Hey guys,
A buddy of mine has an 86 YZ125. The top end was inspected by a small engine company and it was determined he needed new rings, so after replacing the rings and making sure the top end is all there, it's time to tune the carb.
The bike has stock jetting except a 45 pilot where a 40 would be. The air filter is new, oiled, and clean.
Symptoms:
Leaking vent tubes, going to check float height and needle valve this week.
Revs up fine in neutral, but underload has a hard time going from midrange to the powerband. it's fine once it's in the powerband.
Very bad low end power but it's a 125 so what can you expect.
My plans: Throw stock pilot in there and set the needle one setting leaner. Fix the float height.
Other random issue: When he gave me the bike to look at I think he had kicked it over and over, as after bump starting twice with no luck, I finally managed to get it started and about 3 cups of gas came shooting out of the exhaust in the form of black sludge. While this was going on it seemed to be leaking gas out of the powervalve cover (???), this is not comfirmed, it was just dripping off the waterpump cover and was originating at some point on the exhaust side of the engine. Problem dissapeared when I finally got it started and cleaned out.
Anything I'm missing or you guys would do to help me square this away?
A buddy of mine has an 86 YZ125. The top end was inspected by a small engine company and it was determined he needed new rings, so after replacing the rings and making sure the top end is all there, it's time to tune the carb.
The bike has stock jetting except a 45 pilot where a 40 would be. The air filter is new, oiled, and clean.
Symptoms:
Leaking vent tubes, going to check float height and needle valve this week.
Revs up fine in neutral, but underload has a hard time going from midrange to the powerband. it's fine once it's in the powerband.
Very bad low end power but it's a 125 so what can you expect.
My plans: Throw stock pilot in there and set the needle one setting leaner. Fix the float height.
Other random issue: When he gave me the bike to look at I think he had kicked it over and over, as after bump starting twice with no luck, I finally managed to get it started and about 3 cups of gas came shooting out of the exhaust in the form of black sludge. While this was going on it seemed to be leaking gas out of the powervalve cover (???), this is not comfirmed, it was just dripping off the waterpump cover and was originating at some point on the exhaust side of the engine. Problem dissapeared when I finally got it started and cleaned out.
Anything I'm missing or you guys would do to help me square this away?
