RD400F mods (from local Portland, OR machinist)

[2stroketimebomb]

Have had my heads cut for squish/c.c./o-ring mods. Exhaust port cut for a standard gasket (not there before). Switching from 1972 VM28 R5 350 carbs to 2003 Keihen PWK28s (KX85). RB Designs http://www.rb-designs.com/ will also be testing a DYNA-S modified for my bike (i hate points!). If it works, I'll most likely buy it! Ron lives right off skyline blvd (NW Thompson). His brother owns Cycle Metrics on a nice twisty bit right up the road. I'll probably be pioneering the carb mod, since we really don't know what the jetting will be, but I've been told to start #45~48 pilots, JJH needles (4th clip) & 150~155 main jets.

Here's a few pics:

Dyna S with his hand made plates !
http://i160.photobucket.com/albums/t163/holypiston/Dyna-ignition-2.jpg

provision cut in the exhaust for standard RD400 exhaust gasket
http://i160.photobucket.com/albums/t163/holypiston/Daytona/RBflange2.jpg

Heads cut /squished & c.c.
http://i160.photobucket.com/albums/t163/holypiston/daytona-14squish.jpg

o-ring cut
http://i160.photobucket.com/albums/t163/holypiston/O-ring-400-a.jpg

http://i160.photobucket.com/albums/t163/holypiston/O-ring-400-d.jpg

PWK28s!!
http://i160.photobucket.com/albums/t163/holypiston/PWK-28-carbs-1.jpg

insert to fill manifold gap
http://i160.photobucket.com/albums/t163/holypiston/PWK-manifold-inserts-1.jpg
http://i160.photobucket.com/albums/t163/holypiston/PWK-manifold-inserts-3.jpg
http://i160.photobucket.com/albums/t163/holypiston/PWK-manifold-inserts-4.jpg

Can't wait to test it out. Should be more efficient and smoother power. I've heard with just the PWK 28 mod on an RZ350 (commuting), a guy is getting around 50 mpg. Not bad

[MA$TER_E]

Wow, thats pretty damn cool :rad:

[2stroketimebomb]

Thanks Masta!

Ron mentioned that part of the reason I probably had such vague jetting problems, was because my squish band and head volume was off. I first measured the squish @ .087"!!! Optimally I think these are done in the .036~.040 clearance range...with the c.c.'s conservative @ 23 c.c. (stock is around 22). Also the head was a one piece that had blowby, it grew and moved around (probably the reason for the stock graphite head gasket by yamaha). he cut the head nicely (to avoid cutting into the gasket area and pretty equal fin-age on both sides). The dowel pins will center it and hold it in place. I had a choice of two different types of o-rings (silicone or viton). We'll try the silicone because it has a higher temp rating. The old carbs i were running were leaking and getting on the chain and everywhere. These should be much better, since i'm going from a roundslide to a flatslide and I hear the Keihens are much easier to tune and live with (not as finicky as an OEM carb). I'll be running period Factory Pipes Products expansion chambers (stinger modified for Toomey T-5 silencers). I should be popping right along this summer.

[JonXX]

That's gonna be wicked quick.

And LOUD. lol

[TOM-CAT]

Nice work. :clapping:

That must have been wicked putting those cylinders on the lathe. Can't imagine they balanced well. :laughing:

[2stroketimebomb]

That's gonna be wicked quick.

And LOUD. lol

Those toomey end cans are LOUD! I wish the silencer core holes were a little smaller. Would probably make it a bit quieter, like the smaller holed cores on our RD350 (J&R poser pipes).

I'm not doing any porting, but you can get someone like Scott Clough Racing to do a stage II and this will probably wheely the first 3 gears w/o a clutch just under power alone w/ that mod, but that wasn't my goal. Just wanted a tighter motor and with the head mods hopefully a cooler /smoother running motor also.

I told Ron that before he did the head mod, i would get the revs to 6k in second gear chop the throttle and then whack it to bring up the front end. He said that I should be able to just rollon the throttle on and bring it up in second w/ the heads right. I'm not expecting that much, but any little bit of power increase helps and I will see if i can get away with stock gearing. That would be nice. So from a 16/39 sprocket to a 16/37...the 39 was nice and 6th didn't feel like overdrive. If the new heads will pull 6th, i can gain at least 5 mph more top speed.

I just pulled the RZ350 head off (Girlfriends bike...she has good taste) and someone has milled that down to the bone...dam. We got a good stock spare and will have that head surfaced and use that. I blew radiator fluid everywhere on a Carson ride, the impeller was chewed up, the tranny was coffee colored and i most likely blew a head gasket..no wonder squish was probably dangerously low and too much compression i'm thinking...thinking .034 or lower!!!

[2stroketimebomb]

Nice work. :clapping:

That must have been wicked putting those cylinders on the lathe. Can't imagine they balanced well. :laughing:

The daytona 1 piece head would have been even worse...super slow speeds. The best thing to do is cut the head in 1/2..so that is what we did. Ron loves the old RDs and helped a few racers back in the day.

Do you know you can buy a CDI german made ignition for the RD with a separate controller to map the ignition every 500 rpm. That's the state of the art and the bees knees for these bikes...but too much coin for me...about a grand for the MZ-B german made CDI and zeeltroinics controller. Best out there and i hear it revs up quick just like the RZ.

man.

Someday...

[Jane Honda]

Masta! :haha:



Those were some really cool pics! :thumbup:

[2stroketimebomb]

Thanks Jane. Anticipation!

Who's the Masta? Sho nuff!

[JonXX]

You might talk to Charlie Brown at Superior Sleeve in NE Portland about a port job too. He did my Blaster and a buddy's Banshee (Banshee motors are the same as yours only different) and they flat out rip.

[2stroketimebomb]

You might talk to Charlie Brown at Superior Sleeve in NE Portland about a port job too. He did my Blaster and a buddy's Banshee (Banshee motors are the same as yours only different) and they flat out rip.

Doesn't he have a couple TZs tucked away somewhere or is that someone else I'm thinking of?

Porting! Probably best spent on the RZ350 (father of the banshee). I know i could get close to SV650 levels of power, but i want to make it through the summer....hhaha. From what i hear the 400s are more prone to eat pistons than the 350s. There was an AHRMA racer a couple years back. Bob Hurst (met him in the pits...I'm not a racer, just was watching them go round). Extreme port job by Harry Barlow (UK). 73-75 rwhp. That's a monster. He had at least 3 or 4 pairs of cylinders, heads, what not. had to change pistons every other race or so (cost him about 12k to do a whole year coast to coast AHRMA back then i believe!!). He's hit about 135 mph (well, he told me he crashed at that speed giving kudos to Barnacle Bill's leathers!!) on that monster. BIG ass carbs. I think they were 38mm (stock is 28mm)? Where i'd run a 230 main jet, he'd be running a 520 main jet @ Sears Point (Infineon). What afriggin monster. He lapped the whole field and caught up to lapped 4th place if i remember correctly. Little RD350 too. I seen a guy drag a knee on a daytona there...only time i've ever seen a someone do that on an RD, but then we're talking late 90s..mm..early 2000 and hardly no one was racing these old dinos.

I hear the AHRMA is coming to PIR. Will have to check that date.

[JonXX]

It wouldn't surprise me if he had a couple TZ's in the back corner.

[2stroketimebomb]

Looks like my motor has passed the vacuum/pressure test. 2003 KX85 flatslides installed, DYNA-S (made to work with the motor...custom ignition plates, cam)..i will be the test mule for this ignition.

Can't wait to pick it up!!

vacuum test:
http://i160.photobucket.com/albums/t163/holypiston/Vacuumtest1.jpg

Pressure test:
http://i160.photobucket.com/albums/t163/holypiston/Pressure-test-2.jpg

Side Views:
http://i160.photobucket.com/albums/t163/holypiston/RD-400F-1.jpg
http://i160.photobucket.com/albums/t163/holypiston/RD-400F-2.jpg

Baby's got back (end):
http://i160.photobucket.com/albums/t163/holypiston/RD-400F-3.jpg

Bring on the spring and break out the stinkwheels!!

[MA$TER_E]

Thats pretty damn cool :thumbup:

[2stroketimebomb]

i hope to take a little camera video of it by this weekend, if i sort my jetting out right.
I'll be doing what your avatar is doing, if i get it sorted.

[2stroketimebomb]

UPDATE: The PK-82 Uni Pod filters are slightly too large by a mm or 2. We also read up that you need that tuned port length of at least an inch (or the midrange gets rich or something like that). When i get the motor in the frame and the carb hooked up, I'll see if we can make a straight up a 1 inch long (2 to 3 inches would be cool) reducer/enlarger spacer to fit between the carb bell and the filter. so the PK-82s are just about 52 mm whereas the bell measures 49mm.....the 4cking box says 50~52mm, but the I.D. is 52 mm and not 50mm.4kers. So i have to see if there is room for a straight away spacer or if we have to angle it inward a bit to fit. Will keep posted with pictures. PK-82 was the closest thing i could find for this weird OD for the intake bell of the PWK-82s

[2stroketimebomb]

It's all pink on the inside (and the outside) for that matter:

http://i160.photobucket.com/albums/t163/holypiston/nycast1.jpg
http://i160.photobucket.com/albums/t163/holypiston/nycast2.jpg

[2stroketimebomb]

Well, I got the bike running. I had wired the ignition out of phase. So a simple wire swap fixed that. Now the carbs are REALLY RICH. Move decision to move to the 4th clip was a bad one i think. I will put that on second clip to see if the pilots are rich also. So, the bike is together and running, but still needs a bit of fine tuning.

http://i160.photobucket.com/albums/t163/holypiston/choo-choo1.jpg
http://i160.photobucket.com/albums/t163/holypiston/choo-choo2.jpg
http://i160.photobucket.com/albums/t163/holypiston/choo-choo3.jpg
http://i160.photobucket.com/albums/t163/holypiston/choo-choo4.jpg

[2stroketimebomb]

Well those chrome end cap pods are going bye-bye. Reading everywhere they are just bad for pressure waves and stuff like that...i could hear it slapping back hard on the pods...not good.

Now that i have a pink slip on (approx. 2"). I can find an ALL foam pod that doesn't mess with the slap back waves....Will be checking float level and returning the needles to the middle clip and letting the slow airjet screws tell me where to go with the slowjets.

:blah-blah: :facesmack:

[2stroketimebomb]

in the middle of my jetting trials. something is rich.

http://www.youtube.com/watch?v=wqpGxeA_SEc

[ZX 14]

Intense Kevin, I hope it all comes together for you!

[2stroketimebomb]

Thanks ZX. The internet is a wonderful thing....getting info and advice from everywhere.

I like my Vantucky smoked to a light blue color.

get er' dun.

[2stroketimebomb]

making progress w/ the idle circuit..

http://www.youtube.com/watch?v=TAvNljdqZJY

[2stroketimebomb]

Been struggling w/ jetting. So far, i think the pilot is right @ 45 pilot...I think. I tried 5th clip all the way down to a super lean 140 main and it's still rich inthe mids even at that low of a main jet, so at least the 5th clip can be ruled OUT!. Middle seems to be the sweet spot. PRevious testing showed even the 4th clip with this main jet was too rich. (keeping a log) A guy in Grand Junction, CO is close @ 155 mains. I found an ultra-light air correction / altitude main jet conversion chart and it came out to 165 main jets. I had 155 main jets in there and it would rev but soft and lean. I'm hoping that the 165 mains will richen up the mids a bit and give me back some of the rip and then i can sort out the needle clip, maybe won't have too.

Air correction @ near 5k feet in elevation:

.95 x 45 = his pilot ( 42) .95 x 165 = his main (155).

Let the fun begin. I'll probably pop in a 168 for a measure of safety...hoping i get some richness near 10k, that would be just about right.

[2stroketimebomb]

well, i got all the way down to a 38 pilot and 1/2 turnson the airscrew. did a dead stop rollon to wfo quickly w/ a 168 ...seemed to rev cleanly. 2nd clip was good, now i find that 1/8th throttle cruising is suffering. Looking at the needle chart (w/ help), it seems the straight diameter needs to be thinner. This is the last "letter" in the 3 letter series. So from a JJH needle to a richer/thinner JJG needle. RB Designs is also comparing my carb internals (OEM kawasaki) to a SUDCO carb and see what differences he can find. Our goal will be to setup the kawasaki PWK28 just like a SUDCO PWK28.

So the fun continues.

[2stroketimebomb]

Still jetting this thing. Wow, from a 38 to a 60 pilot. Now i see why they call these carbs forgiving. I should have seized by now. I was running toulene and then found that fouls the plug readings and i don't have enough compression to be even using it...oh well! been bouncing back and forth between mains and needle selection. I'm still trying to find the right pilot. I think I am close though with a #60 pilot...started at 1-1/2 turns and will probably end up around 1.0. That is good, at least a working airscrew range. 162 seems like the sweet spot for the mains..or feels it anyway. anything richer than middle clip will probably foul a plug. My low end & midrange has been sucking with the smaller pilots . I'm hoping the overlap of a correct larger pilot (thinking i won't have to go larger than #65 pilot) will help my midrange in addition to the richer needle diameter . The 55 would be "ok" cold then the engine warms up and it leans out. I'd start the bike "cold" with a 55 and airscrews at only 5/8ths turns out from full in and it would hang like the choke was on. Even full warm , you'd get that slight hange. I had to jet rich with my last set of carbs on the pilot, but got rewarded with good midrange (daytonas porting is different than the other RD's and the top end signs off earlier. best power is betwen 5800~7800 rpm..then it falls off...you could rev to 9k, but it won't go any further than that, no matter what the main jet size!). Two racers confirmed this! Scott Clough RAcing and a guy in FL. 2006 AHRMA champ. I kept thinking...shit i've gone rich and i've gone lean and i can't get this to rev to 10k...wtf!!! Now I know!

Plenty of people making good suggestions, but when it comes down to it, it's you that has to listen to what the motor wants. I would have to be the one to pioneer this dirt bike carb. should have waited and let someone else spend 100 bucks in jets.

:)

[2stroketimebomb]

Well the port work should alleviate the jetting "bottleneck". This is gonna be a monsta!

Check out the portwork in progress... (RB Designs under direction from Scott Clough Racing).

http://i160.photobucket.com/albums/t163/holypiston/Daytona/RBport5.jpg

http://i160.photobucket.com/albums/t163/holypiston/Daytona/RBport6.jpg

http://i160.photobucket.com/albums/t163/holypiston/Daytona/RBport7.jpg

http://i160.photobucket.com/albums/t163/holypiston/Daytona/RBport8.jpg

http://i160.photobucket.com/albums/t163/holypiston/Daytona/RBport9.jpg

http://i160.photobucket.com/albums/t163/holypiston/Daytona/RBport10.jpg

http://i160.photobucket.com/albums/t163/holypiston/Daytona/RBport11a.jpg


http://i160.photobucket.com/albums/t163/holypiston/Daytona/RBport12.jpg

http://i160.photobucket.com/albums/t163/holypiston/Daytona/RBport13.jpg

http://i160.photobucket.com/albums/t163/holypiston/Daytona/RBport14.jpg

http://i160.photobucket.com/albums/t163/holypiston/Daytona/RBport15.jpg

http://i160.photobucket.com/albums/t163/holypiston/Daytona/RBport16.jpg

http://i160.photobucket.com/albums/t163/holypiston/Daytona/RBport1.jpg

http://i160.photobucket.com/albums/t163/holypiston/Daytona/RBport2.jpg

http://i160.photobucket.com/albums/t163/holypiston/Daytona/RBport4.jpg

http://i160.photobucket.com/albums/t163/holypiston/Daytona/RBport17.jpg

[2stroketimebomb]

http://i160.photobucket.com/albums/t163/holypiston/Daytona/RBport25.jpg

http://i160.photobucket.com/albums/t163/holypiston/Daytona/RBport26.jpg

http://i160.photobucket.com/albums/t163/holypiston/Daytona/RBport23.jpg

http://i160.photobucket.com/albums/t163/holypiston/Daytona/RBport24.jpg

http://i160.photobucket.com/albums/t163/holypiston/Daytona/RBport27.jpg

[2stroketimebomb]

Update: OEM intakes are too soft and the carb could fall out. The banshee intake manifolds can be modded to fit and are stronger. Plus i can run a crossover later if needled.

[2stroketimebomb]

Ron got a break from his usual duties and started thinking on how to make the carb easier to tune. Here is the latest he came up with (airscrew mod and tool).

Really cool stuff. If you look , he also relocated the right side carb (PWK28mm) airscrew...otherwise, both of them would be on the left side.

If you need a guy that does two stroke head mods, boring, crankwork, casework, Ron is your guy.

Really love this little carb tool.

http://i160.photobucket.com/albums/t163/holypiston/Daytona/carb-tuning-tool-1.jpg

http://i160.photobucket.com/albums/t163/holypiston/Daytona/carb-tuning-tool-2.jpg

http://i160.photobucket.com/albums/t163/holypiston/Daytona/carb-tuning-tool-3.jpg

http://i160.photobucket.com/albums/t163/holypiston/Daytona/carb-tuning-tool-4.jpg

http://i160.photobucket.com/albums/t163/holypiston/Daytona/carb-tuning-tool-5.jpg

[2stroketimebomb]

RZ intake manifolds installed (stronger and cheaper!). Also got a banshee pingel petcock that will bolt right up, but failed to notice how big the holes are....will need a 1/4" to 3/16" inch reducer...it's for bigger 33+mm carbs!!

http://i160.photobucket.com/albums/t163/holypiston/Daytona/RZmanifold-3.jpg

[2stroketimebomb]

Pingel Banshee Hi-flow petcock installed w/ RB Designs custom reducers (8mm to 6.4 i believe) this petcock was made for 33 mm and larger carbs...didn't know that.

http://i160.photobucket.com/albums/t163/holypiston/Daytona/pingelinstall1.jpg

[2stroketimebomb]

Ratbike in waiting. I'm gonna un-uglify that front end (remove the accel coils) with some under tank mount XS650 coils.

This is what an RD looked like garage style in the 70s (classic car coils on the downtubes).

http://i160.photobucket.com/albums/t163/holypiston/Daytona/5202010ratawaits.jpg

adapters for vacuum synch

http://i160.photobucket.com/albums/t163/holypiston/Daytona/UPP_RZ_synchadap.jpg

[2stroketimebomb]

Started the bike up for the first time since the Stage II? port job. Seems now the #45 pilot is too lean (bogging a 1/2 and above on the a.s.). Looks like I have to go bigger...like possibly a 50 or 55 pilot.

Here's a current pic:

http://i160.photobucket.com/albums/t163/holypiston/Daytona/stageII-1.jpg

[Flyte Risk]

Can you phiscally fit another bike in that garage?

BTW, Nice thread. Always interesting to follow someone on a new path.

[2stroketimebomb]

Can you phiscally fit another bike in that garage?

BTW, Nice thread. Always interesting to follow someone on a new path.

:lol:They are ALL hers, save the Daytona. That Z1 is a workhorse. We got over 50k miles on it and it's still chugging right along. Needless to say, I have no problems when it comes to getting away on the motorcycle. She GETS IT. :hug:

We have an RD60 in the kitchen and a kawasaki G5 in the living room...another old little suzuki in the backyard and one in the trailer.

I think my GF has hoarding disease, but it's the good kind..

[2stroketimebomb]

A pilot test (45 to 55 pilot) only.


http://www.youtube.com/watch?v=WMgbGUTwmeg&feature=player_embedded



(http://www.youtube.com/watch?v=WMgbGUTwmeg&feature=player_embedded)

[2stroketimebomb]

Took the bike for it's first ride since the port job yesterday. it got worse as it got warmer (engine). Soft is a good term or weak. I have a 155, Ron told me to go richer on the mains for now and leave the other stuff alone. Will try a 162.

[2stroketimebomb]

162 JJH-3 55 pilot. Pilot is good, breaking up @ 1/2 throttle (checked scooter-tech website and 1/2 throttle breakup means a change in needle DIAMETER). the 162 felt rich WFO (burbling). popped the leaner JJJ-3 in and revs up slightly quicker and sound like it cleaned up off throttle..positive sign.

A friend in one of the Carolinas is running a 158 main jet with similar mods. I think I'll try these settings next (right about the time the rains came in):

160 mains ( a step richer, just to be safe)
JJJ-3 (- is the clip position)
55 - 1.5 turns airscrews

[2stroketimebomb]

My GF said the bike sounds better (160 main). Raining until the end of the month. I think i'm getting close now. Just blipped it off the stand. Thinking the main will either be this or the 158. Not much tuning left for the mains and then i can sort the needles if needed.

[2stroketimebomb]

Looks like i mixed up needle diameter w/ needle clip position. RB is telling me 2nd clip. Leaned out on the leaner diameter down low fully hot. It was telling me all along clip position, but i missed that. In between rains.

Going back to original needles, but 2nd clip...lazy midrange.

160
JJH-2
55 @ 1.5 turns.

[2stroketimebomb]

made the move to the 4th clip and installed the RZ350 crossover tube. I think I like it.

http://www.youtube.com/watch?v=j65fUDbgSWg

[2stroketimebomb]

52 pilot

http://www.youtube.com/watch?v=rpL7rxHMVbc

[2stroketimebomb]

My tuner thinks we are getting close on the jetting now. Keep the 52 pilot, BUT go to a leaner diameter needle. So, a change to JJJ-4.

so the pilot looks like it's about right, needles are close and then i can chase the mains in 3rd/4th (plug chop). The 5th when i'm confident it's close. Insulators are dark colored, so richness seems to be a good sign.

I'm just praying my midrange isn't spaghetti soft.

Today should be a good day for a main jet run.

[2stroketimebomb]

Took a long 3 hour ride. found a couple things. the 152 i put in was too rich, the 4th clip was too rich, the needle diameter was ok, but the pilot was too lean (off throttle surging).

I believe this will be the final settings @ 72 degrees F on PREMIX.

150
JJH-3
55 pilot @ 1.5 airscrews (previously tested).

Most RDs that don't have the o-ring head mods and squish band mods that i have will probably run 155 main jets, but it's good to start a little richer (like the daytona). The daytona w/o the mods will probaby run even richer, suggest 162~165 for starters. Needle clip will probably be the same. Pilot for a premix bike will be rich. If you are on the stock injector...it could be anywhere between 38~45 pilot i gather.

I wasn't able to make heads or tails of the jetting until i got the right main jet (plug chop). then the needles fell into place and then i started seeing weakness int eh 45 pilot off throttle. My initial tests were very good with the 52 pilot @ 1.25 and the 55 pilot @ 1.5. The 55 seems the better choice and the most kickass rich crackle that will hold it's own after the bike is full warm. I kept thinking 4th clip was it, but it wasn't and it further clouded my perception of rich and lean. ???which is it???http://www.southbayriders.com/forums/images/smilies/frown.gif

So if anyone has an RD, i hope this helps.

BTW: baseline settings for 2003 KX85 carbs on an RD350:

135-138 mains
JJH-3
#38-40 pilots

2003 KX85 carbs are only 85 bucks a piece from kawasakiparts nation. such a deal for a flatslide Keihin!! and no frigging leaks. O-rings seals in the float bowl and main jet plug are GOOD!!

[2stroketimebomb]

Well everything above leaned out and i was wondering why. I initieally set my timing statically by turning the crank by hand and setting when the 12v L.E.D. light lit up. That's ok (i was reminded later) for an initial STARTTING point, but it was quite a ways off with the bike actually running as i personally found out Doh!!. A zenon strobe light fixed that problem and i had to retard my timing back. That made all the difference and i got my richness back.

2 months of struggling to find out my timing was too far advanced the whole time.

I almost traded these carbs for lesser carbs. I'm glad i found the culprit.

so now w/ the timing retarded the 55 pilot now feels a bit rich and maybe my needle diameter, but in this weather it's running pretty good.

[MA$TER_E]

Ya know I thought about that. I had no clue if it was relevant to your project or not but all this talk about jetting and carbs and the pics of the motor took me back to as a kid out in John Day getting my old suzuki trail bike running. Sit'in out in the driveway, bike propped up on a milk crate cuz it didn't have a stand, stator cover off, a set of feeler gauges adjusting contacts and what not and the awesome difference it made... Gawd I love fuel injection and electronic ignition :yes:

You are the carb wizard as far as I'm concerned :bow:
I've never been to good at adjusting carbs... Gawd damned things...

[2stroketimebomb]

Thanks for the boost Eric, but I've been getting advice from just about everyone...sound familiar? I just take bits and pieces that sound right and try it from there. It is easier to jet when your timing is right. Like trying to tune the bike with an air leak (if the timing is off!).

I'm not expert, by any means, but it's the small stupid things (and i seem to have my share of those) that you figure out later. The bike just always felt lean...now i know why. With that timing so advanced, you could only get so far.

I hear you on the fuel injection. My girlfriend is the big two stroke nut and sometimes can't figure out why i want a nice F3 or F4.

Well, when you finally get down to wrenching on an old bike for say 10 to 15 years, busting your balls....

then you'll know why. She hasn't wrenched much.

I am constantly tinkering. I should have left it alone after the ride last night.

The best it's felt so far with these carbs ( i like it rich in the bottom for an extra boost for the rollon and also when the engine gets full hot, it won't lean out).

So currently 2003 KX85 carbs: 150 mains, JJF-3 (rich diameter) 55 pilots @ 1-1/2 turns. I tried running those smaller pilots (42, 45, 48). but after 45 minutes of riding, i don't like that off throttle surging...hate it. I'll take fat and rich any day over grocery getter perfect. I'm curious to see how it will change from 62 degree to 83 degree. I just hope it's not so fat i foul a plug.

[Flyte Risk]

I know the feeling on the advice thing so I'll keep it short. Plug gap will affect your tune. A big gap with a hot spark will show lean, a tight gap or too cold of a plug will read rich.

[2stroketimebomb]

ok....long story short. shitcan the PWKs. Collaborating between Spec II and RB Designs. I have ordered a set of Spec II classic chambers and now we are wanting to spec the motor to Gary's (spec II) specifications. So head and carb mod changes. Going back to a mikuni carb. ( I recently sand blasted a piston and had a 4 corner seizure with the PWKs..).

We need to recheck out clearances, volume, angle...stuff like that. NOw i have an expert machinist and hopefully the help of a maaster RD tuner (bought his pipes today).

to be continued...

how it goes when you start messing w/ a two stroke dinosaur.

I was getting 2nd gear rollon wheelies, but then the midrange was a marshmallow...crzy...either cruise 1 particular rpm or WFO...i can't deal with that.

[Flyte Risk]

I know another machinist here in the west metro area that could be a good resource for you. If he can fit you in will all his OMRRA clients.

[2stroketimebomb]

Thanks for the offer Mike. Ron is quite good. We were kinda experimenting w/ my daytona and i accepted the risk. Now that i have contact and hopefully some advice from Spec II,( if i didnt' piss him off), we will adj. the motor to Gary's specs. Gary, of all people realize that the daytona was different from ALL the other Rd motors. He knows exactly how much trapped volume i need in my heads. Right now we are comparing numbers, but i don't think the heads are that far off at all. We shall see

the common denominator in both blown motors was the welded many times over pipes and possible restriction from the overwelds and the mismatch with the toomey bansheee end cans. The other problem would be the high compression (if our numbers are off) in the heads...which can be easily adj. for by recutting the heads or just adding a standard copper 400 gasket. I like adj. the head, it's easier to assembly that way with the dowel pins and w/o a gasket.

I'm in good hands. Just the way it goes, especially with a one year motor like this and I don't know anyone else that has done the o-ring head mod on a a daytona motor. learn as you go.

[2stroketimebomb]

I am a bit relieved. Talked w/ Gary of Spec II over the phone not long ago. RB Designs forwarded me his exact head mod and porting mods and i forwarded that to Gary. Gary said the numbers were on and that i should stick with the people doing my motor work (meaning the numbers will work w/ his pipes).

I'm going back to my 1972 R5 350 carbs (Ron is going to see if there is a leak with the new valve seat inside the float bowl and if so maybe find a way to fix it.).

I dropped by Ron's yesterday and a young kid was there w/ a beautiful 1978 RD400E (silver!) w/ brand new Spec II classics on his bike and period rearsets. I asked him how long it took for the pipes to come in. He said that although Gary says his turnaround time from order to shipping is 1 week, it was more like 4 weeks!

It's worth the wait and i've seen my first set of NEW Spec II pipes in person and they look a lot better than the old set i used to have.

[2stroketimebomb]

My brand new Spec II pipes come in a week (Gary @ Spec II ran out of header parts or whatever)! RB has bored my carb from 28 to 29.3mm (old reliable carbs and fixed the leak!).

and what's w/ this July rain. I thought we were done in June-uary!

[2stroketimebomb]

Here is a flow chart that RB Designs sent me showing the improvements over the stock carb bore. Think the bore is now 29.3mm from 28mm. Carbs are my old 1972 R5 350 carbs.

http://i160.photobucket.com/albums/t163/holypiston/Daytona/FLOW_CHART_2.jpg

Now I'm taking this cipro medicine and can't go out in the sun. This will probably be the time when the pipes come in. Hopefully w/ these new pipes (no restrictions), i won't keep blowing holes in the right side piston. Just hoping for a somewhat reliable ride (can't ask for to much on an aircooled motor!).

[2stroketimebomb]

Got the new spec II pipes mounted on (1972 R5 350 carbs/oval-taper bored to 29.3mm). I know a race that runs 170 mains at the racetrack (runs R5 carbs on his RD400C), but i lose a bunch of midrange w/ those. I installed the Spec II recommended 220 mains and it is stronger in the mids (where i ride). RD350-y-boot with tall filter. Jetting: 220 mains, 169-P2 needle jets, 5DP7 needles / 4th clip, 55 pilots @ 1-3/8ths turns (airscrew), 2.0 carb slides (may try 2.5 slides..slightly rich with 2.0 slides, 1.7mm airjets.

Runs "satisfactory" for now. I have it timed @ 2.0, but then read the instructions closely and it seems Spec II recommends 1.9..Still i'm gonna take it for a break-in ride because it rides decently and I've done enough wrenching for now. If i roll on the throttle quick enough it will pop it up in 2nd....I think it's almost there, but you really never attain perfect for too long. So for the 220 mains, i'm trading high rpm revs for a stronger midrange (where i ride m ostly....6k~8.5k). Will dial it in as i find out what the engine will tell me on the local back roads.

[2stroketimebomb]

Ok I finalized my jetting and proved myself w/ a local PNW ride starting at the Sylvan Chevron, through Vernonia and ending @ Deer Island. some of our group got split up and ended up going to Astoria!

I had a couple rules (learn by experience):
1. retard the timing!!!! good thing. For a long ride like this...1.75 BTDC is WAY better than 2.0 BTDC
2. While "high speed" cruising....cruises no higher than 6.5k rpm in top gear on the LONG straights. (this means no faster than a cruising speed of 80 mph to preserve the top end, which put me near the back of the pack (riding w/ the big boys).
3. Rev no higher than 9k rpm (10k is the limit).

I found that the absolute richest setting on the needles is where the bike likes it best. Did the whole ride (i think about 4 hours) and no seizures or any real problems (amazing...testament to RB Designs solid head/carb & port work)...so i think i've pretty much finalized the jetting.

Consistent 2nd gear rollon wheelies w/o using the clutch or chopping the throttle. Just a good whack, even after riding for hours and it comes up.

[Flyte Risk]

(this means no faster than a cruising speed of 80 mph to preserve the top end, which put me near the back of the pack (riding w/ the big boys)

No offense but if thats the case you're riding with the wrong group. We cut it back in the straights to regroup then wick it back up for the twistys. We never have to wait at a turn.

[2stroketimebomb]

No offense but if thats the case you're riding with the wrong group. We cut it back in the straights to regroup then wick it back up for the twistys. We never have to wait at a turn.

What's probably happening here is I'm so far behind that i have to make that up on the straights. Plus i had two riders behind me that i don't want to hold up, but i found that they liked my pace, so all is well.

My rule on my own rides is speed limit on the straights and my speed on the corners. Haven't had any tickets in years doing it this way.

Some people can't slow down to save their own lives though. I'm sure you've been on a ride or two like that.. :eek2:

So i found that i can go the other way. 170 main jet (what most guys are running with R5 1972 carbs) with a rich P4 needle jet, 4.5 clip same pilots and everything else. These are some peculiar piston port carbs in that they allow you to do this. Most people say 170 and i'd have to agree, but i had to make up for lack of midrange with a larger needle jet going from 220 to 170. With the 170 main jet, it's a necessity to go to a P4 needle jet (richer) and that brings back the midrange and the occasional fun clutchless 2nd gear wheelies and the little 3rd gear bump wheelies (if i'm lucky).

definitely some weird as* carbs. you couldn't do this w/ regular RD series carbs.

[Flyte Risk]

My rule on my own rides is speed limit on the straights and my speed on the corners. Haven't had any tickets in years doing it this way.

Some people can't slow down to save their own lives though. I'm sure you've been on a ride or two like that.. :eek2:.

That explains why I ride with the people here almost exclusivly.

[2stroketimebomb]

UPDATE: (long time coming). I've tripled my usual life expectancy for this motor (i usually hole or seize w/i 3k miles). First, I had a damaged dial indicator (which does the timing!). 2nd, i was timing it wrong! what i thought was retarded, was advanced. Once i got HELP! and figured it out, this helped immensely. 3rd, i went w/ a richer ratio on my premix from 32:1 to 24:1...I've got about 9k miles on the bike now, more than i thought i would get. I also had the compression lowered to stock levels (for a 400 C/D anyway) 120 psi..that probably helped w/ the longevity.

So this is the jetting that i have been getting away w/ on 503 to Cougar, Cougar to Carson rides.

1972 R5 CArbs (28 bored to 29.3mm)
240 mains
169-P2 needle jet (shroud cut to 2mm)
5DP7 needles full rich
2.0 slides
2.0 airjets
#30 pilot @ 6/8ths on the airscrews
timing @ 1.9mm BTDC
premix Amsoil Interceptor @ 24:1
B9ES plugs (1 step colder).
Spec II 2010 "Classics" expansion chambers

I've also got some Spec II rearsets that i've mounted up. They look like shit but work very well. Nice to be able to have a little more of a cushion, if i need it. Plus i got rid of the coils blocking the airflow to the motor...Gary @ spec II said this wasn't a good idea.

http://img696.imageshack.us/img696/8408/class2spec.jpg

With any luck, i'll make it through the rest of the summer.

[YAMR6]

It looks pretty, and sounds like you've been busy!

[Jane Honda]

:thumbup:

[2stroketimebomb]

Wow. Thanks YamR6 and Jane!. Been awhile since i last posted. I'm now @ 12,500 miles on the same pro-x cast piston. It may not be as fast now as it once was w/ hopped up compression, but I like longevity over rebuilds every 3k miles.

So I've easily achieved my goal of making it through the summer and then some.

Daytonas are a little trickier to setup w/ their port differences, head volumes, gasket types thicknesses and all that. I basically told the machinist to make the engine internals as close to a 1976~1978 RD400 engine as possible. so i lose a bit of compression, but i gain some longevity.

12, 500 miles and still running good..can't complain.

[2stroketimebomb]

Well,

Merry Christmas and seize free new year to y'all....especially those w/ ninja 250s that don't check your oil tsk. tsk...check it frequently! Our nephew seized his when he didn't bother to check it daily...funny, a 4 stroke seizing.

I tore down the motor at 13,500 miles. I was surprised to find that it has handled the wear and tear of normal everyday riding (i'm not an insane rider) pretty well. I run mainly the full synthetic Amsoil, but at a much richer 24:1 ratio. My previous teardown was at 5k miles and I remembered a racer's advice to sand down any high spots you find on the piston and slap it back together. I think the pistons look alright. I also jetted the bike as rich in the mains and the midrange as it could stand. Seems to be working and no seizures...that is always good. For winter I went to a P4 needle jet from a P2 since i was always full rich on the needles...just the taddest bit rich and was alright w/ the stock 0.022" thickness base gasket. An old racer sold me some TZ one piece base gaskets and that lowered my squish from 0.042" (120 psi) to 0.034"...the gasket is 0.014" thick. I noticed right away it felt more torque, so that is good. Nice to be able to adjust squish w/ just a base gasket and go back if i like to my previous clearance this way. The timing didn't change (rechecked upon base gasket replacement). I regret dropping to a 15 tooth because 6th gear revs out too quick and i like cruising 80mph vs. a tops aof 70 mph w/ the 15 tooth, so back in the 16 tooth front will go.

here's a few pics:

[2stroketimebomb]

HEre's a video w/ it running w/ the thinner base gasket installed. I now find that i need to go back to the P2 needle jet...just slightly rich w/ the thinner gasket.

Should do a compression test to see if how far that might have gone up...don't think it would be much, but still curiuous....run the gas out and then do it!

http://www.youtube.com/watch?v=ZC1hum6QRq4

[Jane Honda]

:thumbup: