85 250r carb problem

[tbus93]

On my 85 atc 250r after I bought it the stock 34mm pj carb idle adjustment isn't working the bike starts and runs just fine but with a little throttle and when you let off it idles it self to low and dies does it if I left of the throttle while riding as well help??

[shortline10]

Couple things to check , small jet might be a little clogged , also do a compression check on the motor , 2 strokes don't like to idle when they have low compression .

[tbus93]

The compression is a little low on this bike sitting at 140-145 but that's what it was after I bought it and it idled just fine then recently I can't get it to idle I had to put a new petcock on it so I wouldn't be surprised if it needs to be rejected because the old one was clogged up

[yaegerb]

140-145?? Way too low. Need new rings and a bore/hone. Minimum acceptable level for compression on an 85-86 R is 170. Fix that before you screw with your carb because your carb might be fine. BTW, while you are in there, replace the base gasket that you said is leaking. That's another reason it won't idle.

[tbus93]

I can't deny it does need new rings and a hone/bore I ordered a 39mm pwk for it my uncles 85 atc leaks twice as much and his compression is sittin at 205

[yaegerb]

I can't deny it does need new rings and a hone/bore I ordered a 39mm pwk for it my uncles 85 atc leaks twice as much and his compression is sittin at 205

I don't understand the point you are trying to make. Compression sitting at 205 is way too high for a stock motor, 190 is as high as you can go with new rings, bore/hone. Maybe he's running race gas and has a big bore?

Anway, good luck with dialing in the 39PWK, I can guarantee without fixing the aforementioned problems it won't run as crisp or possibly any better than it does now.

[tbus93]

I will probably pull the motor after the weekend I won't be able to ride for two weeks should be enough time to get all the parts to fix it up