Only runs with full choke
- Thread starter mikaleno
- Start date
TheNecromancer13
Active Member
Sounds like you might still have an air leak somewhere.
TheNecromancer13
Active Member
I used RTV on one once, but I had to use a ****load of it and it took 3 tries.
I've always used Permatex copper gasket sealant for any leaks. It never really dries, cleans up easy and lasts a long time. I've had the same tube for about 19 years.
If it only runs on full choke it may have a whacked out float height or a clogged jet keeping it from getting the gas, too. I have had the jet clog twice and I have a filter in the line. The kit tanks are cruddy and the gasohol rots o rings and cheap seals sometimes. The tiny black cruds will clog stuff.
Hope you get it going.
If it only runs on full choke it may have a whacked out float height or a clogged jet keeping it from getting the gas, too. I have had the jet clog twice and I have a filter in the line. The kit tanks are cruddy and the gasohol rots o rings and cheap seals sometimes. The tiny black cruds will clog stuff.
Hope you get it going.
OK, I had a new (NT) carb lying around and threw that on, (no O-ring). That cured the full-on chock condition and it's now operating fine. Now I'm getting the 4 cycling condition and then it kicks in the does the 2-stroke, so it's on and off. I'm running 20:1 cos i'm breaking in my new rings. Do you think that's what making it do the 4-stroke?
Run it out or drain into a container and add a little gas to get to 32/1. Or mix a new batch. Too much oil actually makes your fuel/air mix leaner but all the oil washing through fouls up the running so you can't tell it.
If it 4 strokes at low RPM but clears up and runs well at full throttle, your main jet is ok. Lean the needle by dropping it.
If it 4 strokes everywhere it probably needs float height set, checked for tune and if still out (on the top end), rejetted, then set the needle.
From idle to 3/4 throttle you're on the needle, from 3/4 on up the needle is withdrawn from the jet and the jet is all that counts.
Hope this helps.
Just guessing but after the gas is right drop the needle. It's all trial and error, but it is logical. Fun really. Take your time and change one thing at a time.
To tune a new engine before its broken in is tough, just make sure it isn't overly lean but does 2 stroke most the time.
Once the rings seat it might need more adjusting anyway.
Yep, dumped what was left in my tank into my Ga. jug then topped it off at the station just to thin it out a little. Then dropped my needle one click to it's lowest setting. I'll test drive it tomorrow... I bet my neighbors love my new expansion chamber, it's crackling fresh. Lol.
If the engine hasn't finished breaking in, I'd leave it alone until it does. As they break in they become more efficient pumps. The jetting required will be changing.
If it is broken in, needle at lowest setting, and bogging rich at the low end, check your float height. It could be too high feeding too much fuel.
If that is good, try one size smaller main and start all over again.
Ain't this fun?
If it is broken in, needle at lowest setting, and bogging rich at the low end, check your float height. It could be too high feeding too much fuel.
If that is good, try one size smaller main and start all over again.
Ain't this fun?
Tyler6357
Well-Known Member
It sounds like it's 4 stroking pretty badly and that is what probably caused the blown gasket. If you have put the needle clip on the leanest setting and it's still 4 stroking you should jet down but Slogger is right, it is best to break the rings in before fine tuning.
Yep. I figured as you break in it will need that 'extra gas' that is making it burble. More power, more gas. An engine can be looked at like an air pump.
The better those rings seal, the more air it will draw. Then the extra gas is just right. Best to break it in first.
Good luck to ya, happy trails!
