Winter project: upgrading time! (R6 forks and more...)

Yeah the new shed is a big project for me. Lots to learn on working with wood and concrete instead of steel haha.

Yeah I might not split the cases this time due to time constraints. I would like to take a peek since I've never had it open since I own the bike (12+years). Don't want to spend to much time on the bike with the shed waiting.

Anyway I designed the lower arms of the engine stand to be removable. Should allow the bottom end to be pulled.
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I am a little late to the party on these stand pics, this is my original engine which I replaced. I live near a Pratt and Whitney engine factory. This really heavy duty stand came off one of the shop floors when they started downsizing. I think I paid $75 .


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Alright! It's back together and started! Happy with that.

Am having troubles with a hanging idle or the revs not coming down when I give it some gas. My first thought was a bit of leanness in the pilot circuit. Tweaked the mix screws further open but no result. It feel different, the revs are nog going down slow, bit just staying there. Starts pretty good, idles nicely.

Tried some things but no luck. Any tips?

- valves are set
- cam chain tension set
- checked and retorqued the intake boots
- checked with deo for air leaks around the carb
- hooked up a manometer, looks good.
- gas cable not binding
- choke is visually closed
- didn't change or open the carbs, only added a remote idle set screw
Tried to see the timing on the VAPE ignition. There are no markings but it's about on the intersection of where the flat bit meets the circle (left side). When I rev it, it advances like I would expect.

Note about the video, the frame rate is really messing up the strobe effect. The light would flash constant but it seems to be missing a beat every now and then. It actually happens in the video.

So I just retracted that idle adjustment screw a bunch. This seemed to have cured that hanging idle!

They still come down a bit slow but seems alright. Keeps a steady idle around 1000 rpm. Only every now and then it sounds like it misfires
So the main reason i decided to rebuild / de-carbon the engine was some weird metallic sound i heard. I did some testing the last couple days and unfortunately i heard it again after the rebuild....

kind of a bummer. Gave it some thought, talked about it with a friend and decided to see if something is rattling. Because I also hear these sounds after hard acceleration closing the throttle. I made a temporary bracket for the exhausts, isolated the mufflers with some glassfiber and removed the chain guard. Did some testing and holy moly, i dont hear it anymore.

So i could have rebuild my engine for....the fun of it haha:whistle:

Going to do some more testing, to see if this was really causing it.

Since everything was super clean after the build, i could clearly spot some leaking. seems weird some of these have cap nut, and some dont. this one is leaking, shouldn't this be capped??


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Never taken the bottom end apart, can I just remove that one nut without something unspinning on the inside
Yes. That stud should be firmly fastened into the upper case. Replacing the nut and washer shouldn't cause any problems.
So I decided to go to heiden tuning for some support on the carb tuning. He was real busy and had no to little experience with the keihins CVK34. He recommended a pair of new mikuni VM34. Pre jetted for the XS. Since I got very limited time I decided to go this route. Hoping it needs minimal tuning effort to get it running good.

Storing the keihins for later.




Wanted to tune the idle as required today with a buddy. The install went smooth, set the cables by feel to get it started. Started on the first kick! Touched the gas and the cable snapped (crap!) It's a sealed splitter from 2-1, guess I gotta wait a bit more
But the new carbs are not the sollution to my issues.... Unfortunately.

Installed them, and synched them at idle in order to proceed synching them off-idle. But I'm getting basically the same weird symptoms at idle as with the other keihin carbs....

Sometimes hard to start, might idle nicely at 1100 for a while and then starting to misfire. Or the idle would be low and the bike would stall. Or idle would shoot up to 2500.

When it would idle high, I saw with the timing light that the ignition starts to advance.

Anyway kinda done with this bike.

I called heiden tuning about my issues and he had some doubts about my timing. Mainly the timing of the camshaft. I showed him the pictures of my installation last winter. Where I couldn't get the camshaft at 12 o clock. But 5 for or after. He recommended me checking it again because now the head is torqued. Send him this picture:

The crank position was verified with a small screwdriver, and correct. Although it's hard to help over the phone, he got a camshaft and eyeballed my angle. Could be a tooth aka 10° off. This could explain why the problem is still here with a different carb. And affect the idle according to him.

Anyway, I regret not putting in a new chain last winter. Lesson learned I guess. Thinking about what to do, ride my other bike and work on this next year. Do it myself or have him do it. My shed looks like this at the moment so I got enough projects right now haha

Had some time in between the new shed project. So I decided to swap the cam chain. Since I had no shed it had to be done in the living room haha.

The new chain went in smooth. Since I only had to take the valve cover off. We switched it one tooth. Since the guess was, that was issue. It annoyed me how the new chain would also not align properly at 12oclock at the cam sprocket. Now it just a hair before the 12oclock marking. My only guess why, is that the sprocket seems to be a press fit on the cam. Maybe it's been removed before I had it and pressed back on, just out of alignment?

Anyway put it all back together and did 2 small test runs. I really think I had it one tooth off! Because the bike is not showing the same weird symptoms anymore.

Few things I need to sort. It only starts cold without choke, and I need to fiddle with the gas a bit to keep it going. And while cold it seems to have a off-idle-stumble. But ones a bit warmed up she's running nice! Idle would be nice for most of the test ride. Only in the end it would climb slowly at traffic lights from 1200 to 1600.

No weird idle hang anymore.

I did some Googling on a vm34 guide, there seems to have been one in the past? But all the links are dead. Anyone here that has it?

O and did some real life FEM analysis on the way back. The shifter I made, snapped. I guess I need to redesign that to make it stronger.