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roadhor

TTR 125 valve clearance

11 posts in this topic

Could someone that has a manual please tell me where to set the valve lash on my Daughter's 125 TTR ? Also I've read that adding heavier oil in the forks is a good thing to do , but was wondering if anyone has ever tried 30wt motor oil in the forks ? Would it hurt anything ? Thanks for the help.

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intake valve 0.08mm-0.12mm

exaust valve 0.10mm -0.14mm I think you want the valve clearance, which is the distance between the valve stem and rocker arm at TDC

Backlash is something different, it is the distance a sprocket moves backward after the power to move it in one direction is relieved

never heard of anyone going over 15w on the fork oil

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Thank you Florida , Yea I want the valve clearances , I've heard it called a bunch of different things including "lash" but that mat not be correct terminology. Thanks for your help , I may try some no-detergent 30wt motor oil in the front forks so to see what happens. Thanks again. Rob

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Man that 30 wt oil is thicker than you think.. may take out your seals too.. May want to look at the thickest fork oil or atf. I think most people would discourage the 30 wt oil but everyone here tries everything!!

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just bought my 15 yo daughter an 03 tt-r 125, originally thought the carb was the issue but after some work I want to think I need to adjust the valves, the bike idles great revs to low rpm, but when help open it wants to cut out to the point of dying and the exhaust turns cherry red. I'm thinking someone has tried to adjust the valves and got them to tight. can anyone tell me if I am heading in the right direction with my thoughts. Thanks for any help

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just bought my 15 yo daughter an 03 tt-r 125, originally thought the carb was the issue but after some work I want to think I need to adjust the valves, the bike idles great revs to low rpm, but when help open it wants to cut out to the point of dying and the exhaust turns cherry red. I'm thinking someone has tried to adjust the valves and got them to tight. can anyone tell me if I am heading in the right direction with my thoughts. Thanks for any help

Yes, whenever I pick up a used bike I always give it a good tune up and checking the valve clearance is right up the top of the list [tight valve clearance will eventually lead to burnt valves!] Bigdaddy450 is correct [intake .0031~.0047in.] [exhaust.0039~.0055in] Remove both  plugs on the left hand engine cover, turn the crankshaft counterclockwise with the rotor nut till the little "I" on the rotor lines up with the ^ mark on the crankcase cover, measure the clearances. Also wouldn't be a bad idea to pull the carb and give it a thorough cleaning while you are at it, be sure you can clearly see through both the main and pilot jets when held up to a light source. Stock main jet size is #105, although if the airbox has been modded you should have a #107.5 or #110. Needle clip should be in the middle position. You may also need to remove the little cap over the fuel screw in order to fine tune the adjustment. Hope this helps!

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Thank you Racer, I knew part of what you posted. the rest of the info was very helpful,, and the part of removing the little cap I had no idea about. I will post back afterwhile and let you know what I found and if I have it lined out.

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Those have horrible carbs (well, I think so anyway)

A larger pilot jet will makes. Huge difference, assuming the rest of the carb is ok.

One I had I never could get it right- first carb that ever defeated me.

I replaced it with a different one and it was like night and day.

I have the info around someplace for the pilot jet size to try.

Going from 5wt to 30wt is an awfully big jump.

What is the issue?

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Thank you Racer, I knew part of what you posted. the rest of the info was very helpful,, and the part of removing the little cap I had no idea about. I will post back afterwhile and let you know what I found and if I have it lined out.

Some years the factory put a little cap over the fuel screw, most have long been removed by now but thought I should mention it. The adjustment screw is on the bottom of the carb, just in front of the float bowl, turning it out richens the mixture, in the leaner.

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