Ok guys. Thanks for the help in the past. My newly rebuilt LT80 idles fine but under load it dies unless I keep the choke "on" and it runs like a champ. It idles fine both without the choke "on" and with the choke "on". However it dies out when giving it gas under load unless the choke is "on", then it runs fine. This also did this before the rebuild so I have obviously missed something here in the fuel delivery arena.

Here is some background: This machine is old 1987 and has been well used when I got it. It would not idle and would die under load so 2 years ago I rebuilt the carb and replaced the vaccume fuel shut off with a normal (on/off/reserve) petcock. The needle in the carb was shot. Put the carb back on and now it would run, but with the choke "on" only. Compression was bad on the engine (50PSI). So I thought that was contributing to the "choke on runing only issue" So this year I went into the engine and clutches and replaced it all. Now it idles fine but still dies out under load. What have I missed checking? I have read some guys have lack of fuel from a clogged vent cap on the gas tank, I have not checked that yet? Should I go into the carb again? Thanks this is bugging me now.

 

Yes, get into the carb again. It's in one of the lil passageways prolly.

 

I have read about guys saying they have "boiled" the carb? What does this mean? They aren't really boiling it in a pot of hot water are they????
When I rebuilt the carb I let it set in a can of carb cleaner for a day or so, then took everything out, cleaned it and blasted the ports with compressed air. Should I have done something else?

 

You did what I usually did. Berrymans Chem Dip,then spray with carb cleaner,but as LT80 mentions sounds like you missed a passage or something if it only runs good on choke. Old fashioned way that some people swear by is water,vinegar and lemon juice.But I'd still spray em out with carb cleaner even after doing this.

 

Is there a float adjustment of these carbs? I am wondering if the needle is not opening enough and I have the float off. I dont understand what the prime plunger bypasses to allow the machine to run under normal power but when its off, she dies like out of gas.

 

I wonder if the o-ring that goes under the main jet is swelled.
That has been a problem before.
Remove it and go.