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Mikuni TM33 Trouble

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I just installed a new TM33 on my KLR250. It runs great on the low - midrange, but when I open it up it seems very limited at about 7,000 RPM's. It runs very smooth up to a certain point and then it seems like it's governed or restricted somehow. I am running the stock 127.5 main jet. The bike ran fine with the CVK34 & 118 main, so I don't think there's anything else that could be wrong with the bike.

Any ideas? Do I need a bigger main jet?

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Remove the air filter and use a mirror to look at the slide. Make sure it is opening all the way.

Ride on

Brewster

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how did you mount the carb on your bike?

i have just fitted one of these to my old klr as well and had to modify a few things to get it to fit, just wondering if you did things an easier way..

do you have any pics?

i haven't got mine running yet, bought d.o.a. so am unable to help in that respect, but am very interested in how you are going with yours, I should have mine going by this weekend and then will report what it does.

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thanks for the tip Brewster, but the slide is opening just fine. I still don't know what could cause the governing effect that I am consistantly getting.

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hey heller44,

I had to build a special throttle cable bracket. The stock one that came with my TM33 was a bit tall. Actually the whole carb sits a few degrees to the right, but it fits nicely after a little grinding on my right motor mount. I have a pic I can email, send a note to swerld@yahoo.com and I will reply with a pic.

I am still having the problem at 7500 RPM's where the intake seems restricted at that level and won't move past that speed. It is the same in any gear.

I am enjoying the performance increase though for general riding. I hope to eventually find the tuning problem with the high end. I'm thinking that I may need to check my needle adjustment, but that requires me taking the carb apart.

Hopefully someone will offer another useful tip.

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I just installed a new TM33 on my KLR250. It runs great on the low - midrange, but when I open it up it seems very limited at about 7,000 RPM's. It runs very smooth up to a certain point and then it seems like it's governed or restricted somehow. I am running the stock 127.5 main jet. The bike ran fine with the CVK34 & 118 main, so I don't think there's anything else that could be wrong with the bike.

Any ideas? Do I need a bigger main jet?

The 33mm pumper on my KLX300 uses a 145 main jet. You may want to try a bigger jet to see if that helps.

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i looked, and i am currently running a 37.5 pilot, and 125 main.

had a problem similar to yours when i first fired it up, wouldn't read over ~7 thou on the guage. turns out that it didn't like running without a battery. installed a 68mF cap in the place of one and it hits redline when it sounds like it should.

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