Hi Guys

I have a problem in my datto it smokes a bit in higher rpm and smells fuel and also engine idle speed vary depend on the engine temp and also sometimes when i engage clutch it increase rpm(but not always), my mechanic said the Idle Air Mixture screw doesn't funtion so he can't tune the engine he was trying his best but could not sort out the issue.

what would you guys think ?
what cause this to happen ?
i am going to try it on next Saturday again so need your guys help

thanks
Regards
sumith

I would think to replace idle mixture screw perhaps.

What colour smoke?

If smoke is black then is excess fuel/too rich mixture.

If blue then oil

If white then water

Hi thedevilshands

Actually smoke is black a bit, we checked the needle and it was ok, and also replaced the rubber o-ring on it too ..

thanks
Regards
sumith

Hey Sumith, I'm confused
You said

Quote: "my mechanic said the Idle Air Mixture screw doesn't funtion so he can't tune the engine he was trying his best but could not sort out the issue."

and now you say

Quote: "we checked the needle and it was ok, and also replaced the rubber o-ring on it too .."

The idle adjustment screw is OK now?

Hi Mate

Actually by look of it ,nothing wrong for better confirm we replaced the o-ring too, is that possible it to go wrong or not functioning, my mechanic has never come a cross such a situation , don't know exactly, only think it doesn't respond to the tune up, best think is to buy another one and see right ?

thanks
Regards
sumith

When in doubt always replace the cheap stuff first!!

maybe its just an ignition problem and its not burning all the fuel,rather than the carb supplying to much fuel.

Hi greendog

I doubt it is an ignition problem ,because recently i have reaplaced the spark plugs , contact point and ignition coil and ignition condensor including air and fuel filter too..the only problem is that since you can't adjust air flow it smokes and no smoothing (simply Idle Air mixture adjustment doesn't do any thing to the engine idle speed .



thanks
regards
sumith

perhaps the contact point gap is not correct? what gap do you set the contact point? (sorry bad english)

Hi Guys

May be i will try this week end if not try to put new carburetor rebuild kit perhaps to see how it goes ?

thanks
Regards
sumith