hello

i just got a 1985 atc 125m it wont run. i clean the carb all the jets,filter,etc i have spark. i cant check compression cuase you need the engine warm up at operating temp before you can check compression, it seems to have some cuase if i can the intake off and place my had over it i can feel a sucking. all i know my arm is getting tried of pulling!!!! lol

any ideas?

 

Do the compression anyway. Hot or cold will vary, very little.

Also you can give it a shot of ether and see if it pops or starts. This will tell you if it's fuel or something else.

Also you might take it to the top of a very big hill and try and push start it instead of pulling your arm off.

 

i did the compression test even tho my adpter (mine adpter is shorter then the spark plug for reach that is) dont reach down there it was reading about 30 psi...... i did have some poping noise and it backfire once but nothing after that

i was reading somewhere with it not reaching it will get a fase reading ( my adpter not reaching like the spark plug does)

 

i was also thinking maybe cam timing is off? i havent check that yet

 

i have a bad feeling its got low compression damn i hope not if so well then...

 

If you got 30 psi and you had a screw in compression tester that is good.....your done. It won't even light at 30 psi. You have found your problem.

Take it apart and see what's up.

 

ok i guess i could have a stuck value but most likey bad rings damn

 

or maybe even a stuck ring but i doubt it will be that easy damnnnn what does it cost for a head and piston, rings now a days? is it even worth repairing it?

what sucks is i dont know how good the rest of the enigne is meaning clutch,etc

 

I don't know but nothings cheap nowdays as you know!!
One thing you can do to give you an idea what is wrong is do a leakdown.

If you don't know what that is just Google it.

You can make a leakdown tool by using an old sparkplug and an aircompressor with a regulator on it.

 

i have a hand pump leak down tester i would have to make a adpter for it to fit but been awhile sense i have done engine repair if i recall i have to block off exhaust and intake? and by doing a leak down test what will that show? or how will that help me narrow the problem done? been a long time sense i have play with engines so refreash my memory please