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Discussion Starter #1
Anybody know where jets can be bought for this carb? Searched here and with Google and am running into a wall.



I have a 114 main, stock jet, and it's just running way rich. I may have to change to a different carb or try lowering the fuel level in the bowl.
 

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These things tend to develop a wandering idle when you lower the float level. Rejetting and leaning the pilot is probably your best bet.



The 114 works well for me from my home elevation of about 4,000 until somewhere just south of 8,000 feet. When I say "well" I mean "acceptable", but far from optimum at much above 7,000. Within a very short distance from home I can be near sea level or at 9,000 feet, depending on which fork in the road I take, so jetting has always been a compromise. Having witnessed your riding style
you need it optimized. I'm curious to see what you come up with.



I've currently been running the late model CV carb with its corresponding stock jetting as an experiment in hopes that it would offer at least some advantage in the higher elevations, but no joy. It's just as bad and suffers that slight (but present) "CV Lag" when you whack on it.



Seems someone in here was able to source 110's or maybe even smaller and used them on a Colorado trip. Can't 'member who right now, but they'll prolly come forward
 

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I agree. I have a cv carb and my buddy matt has the old carb "which i like better" and both bikes started to studdder in the higher rpm's at about the same elevation somewhere around 8-9,000' but they will keep running up higher. You could put some holes in the airbox lid and just plug them when not needed if you cant find any jets but i imagine they are available.
 

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Discussion Starter #4
Thanks for the replies. Surprised about the CV not being better. I did not know the newer bikes had CV. I've been running a CV carb on 250/300 KLX's since 94 and like them. I don't mind the lag and do like the smooth power control. I run the KLX from 3 to 8K with no change other than the normal power loss at higher elevations. Generally CV's are supposed to be less sensitive to elevation changes. I may try one and see what it does for me on the TW.



In the meantime I dumped out many years collection of jets that came mostly from I don't remember where. But I did discover that the old 6MM hex head Mikuni jets have the same thread and fit perfectly. At least to the eye and feel. I didn't have anything below 114 but I ordered a 110 and a 105 from PJ Motorcycles that have shipped and should be here in a couple of days. I'll let ya'll know what happens.
 

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Discussion Starter #5
Thought I'd update my progress.



I goofed up a bit on my main jet selection. I had went by memory (not good to do at 71)and thought the main jets that were fitting the TK were Mikuni. Didn't fit. Went back to my stash of jets and looked a little closer at the ones that fit. There was a clearly marked star-burst K on the jets indicating they were Keihin. My bad. The jets I have are long body. I called PJ Motorsports and asked if one of their short main jets had the same thread as the 6mm long hex head. They said that was 99101-393. They are round with a flat screwdriver slot. The steps were smaller in the jet ranges so I ordered a 112 and a 110 this time around.



In the meantime I removed the little washer under the needle clip, turned the idle mixture screw way in, and lowered the fuel level to about 1/4 inch below the float bowl gasketed surfaces. The darn thing is running pretty good! If it weren't for the fact that I'll be at this elevation for 2-3 months, I would not bother with the leaner main. But I'll get to see what effect it has on WOT even though I'm not there very much.



New main jet testing to follow.............



http://www.pjmotorsports.com/keihin-jets.html#main jets (scroll down to 99101-393)
 

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I have an idea where you may have gone afoul.



"Correct" float bowl fuel level for the early carb is 7.5-8.5 mm below the seam, whereas the CV carb fuel level is even with the seam. The manual is kinda confuzzling.



Maybe yours was too high to begin with? Might explain some of it since you've now lowered it to 6mm.
 

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Discussion Starter #7 (Edited)
Ok. Bike is finally running pretty good at 7,500 feet elevation. Possibly a tad rich but not much. Current jetting: 105 Main, 45 Slow Jet out 1 1/2 turns, fuel bowl level set at 28mm on the float.

Here's the story on the 45 Slow Jet. I bought the bike at around 3,000 feet elevation. Even with the mixture screw out 4 1/2 turns it would barely run enough to warm up with the choke out. Very sensitive to throttle input even when warmed up. I raised the fuel level up to the mating surfaces of the bowl and that resulted in semi-acceptable performance, with the mixture screw still out 4 1/2 turn. The mixture screw actually fell out once on the cases but I didn't lose it. It was somewhere past 4 1/2 turns.

When I got to the 7,500 foot level where I'm now camped it would not tolerate the high fuel level setting. And the fun began. Lowered the fuel to 6mm and turned the mixture screw in to 2 1/2 turns. It was back firing down steep slopes! Idle still to lean. I'll spare the details but I have about 8 main jets now. I was beginning to think I had a bad coil or CDI.

Very happy this evening when she cleaned up on 105 main. She was still ratty at 108 even. I'll see how things are at 10,500 tomorrow. If too ratty, I have a 103 to try.

Throttle response is much better with the 45 idle jet. I found it in my accumulated stash of jets.

Anyone have a CV carb they'd like to trade for a TK? Nothing to do now that I have the Tk sort of sorted out.
 

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The variables on stuff are difficult to account for. I live at 4,000 feet and run the 40/114. Starts chokeless on the first kick even when cold andpower loss/ rich condition is negligible until well over 8,000 feet.

Can't explain your results, but if it ain't broke I reckon you can stop fixin' it. lol.
 

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Discussion Starter #9
Who knows? I bought a 1976 Yamaha IT250 second hand way back when that had an IT400 main jet emulsion tube in it. That took a while to find.

I've read elsewhere on this forum where people had the idle enrichment screw turned out 4 or more turns to get it to start and idle. And long waits for the engine to warm enough to ride.

The carb was of course cleaned right after I bought it and tiny copper wires were ran through all orifices including air jets.

It's been a puzzler. Needing to figure out what jets fit didn't make it any easier.
 
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