Hey All,

First post here. Use to post elsewhere but certain LT80 experts abandoned years ago... Anyway.

Long story short:

92 LT80

Someone's been in it, but I don't know to what extent. Stock carb, air cleaner, pipe, etc. Nothing "high performance" that I can see.

160 PSI compression
new air filter
Clean carb
New plug (BR7HS, and BR8HS)
Added another ground wire just to make sure.

Quad is getting worse every time I start it. Ran it the other day myself, and it seemed slow, but figured I'd get my son on it in the yard anyway. Later when he rode it it was really slow (6-8MPH). Brought it in last night, cleaned the carb thoroughly, put a new air filter on, changed plug, etc. It fired right up, but it was late, couldn't test it. Fired it up just now, and it barely turns the back wheels.

Thanks in Advance,
Tom

 

An update on this...

I cooked out the pipe today (posted elsewhere here), and it's running better. Unfortunately I would say it's back where it was a few days ago. Better, but still not right.

Low RPMs sound OK, but when it gets up higher it sputters, and just won't rev any higher. With me (210lbs) on it, I need a long flat straight to get it to top speed which is really bad compared to where it use to be.

I use to pull wheelies on this a few years ago with no effort.

Also, clutch is engaging at low RPMS. I'll have to figure out what's going on there too.

 

Another update....

No replies so I just kept plugging away at it. Ended up ordering boyesen reeds, and a few main jets. Went with the 90 main, and fired it up. Revving a lot higher now, sputters at the top still, but I don't know if there's anything I can do about it. I ran around the yard a few times, and checked the plug. It seemed a little on the light side. Moved the needle clip from the top slot to the second, and ran around a few more times. It was a little darker, but still light. Let the boy run it around for about 15 minutes, and checked it again. It is tan on 1 side, and I'd say brown on the other with a little bit of oil on the plug. Sound about right?

The power is definitely back to where I remember it when we first got it. If I lean back a little and nail it it wheelies no problem. I had to turn the throttle limit screw in until there was only about 5/16th of an inch of threads showing. I would guess that he's running between 12 and 15 MPH with it that limited. I tried his hot wheels radar gun on it last week, and it didn't really work.

Now that I'm pretty happy with the motor I'm gonna check on the clutches. I've never had them apart.

 

Was the reed cracked?

 

Hey Jack,

No the reed was fine. I just figured as long as I was in it I would put the boyesen one in. Only thing I can figure at this point is that some of the gunk from when I heated the pipe took a while to find it's way out. You had advised me to heat the pipe up when I first got it, but I never did because it was freshly painted. This year it got to that "last resort" status, and I finally did it.

 

Sounds like you have it licked mostly. I've got a later model lt-80 that smokes like a banshee. Runnning way to rich. Wondering how yours does and if you ever had to address excessive exhaust smoke? Sorry, not trying to hijack your thread, just sounds like you've turned some wrenches on your machine and may have seen this before.

 

When I first got it, it smoked like a SOB. I swapped in a new carb, and it smoked less, but still smoked a lot. Turns out the original carb had a 97.5 main jet in it, with 92.5 being stock. It smokes less with the 90 main jet now, but it's still a smoker. The plug isn't soaked in oil anymore though. There is a little bit of oil around the outside, but not soaked.

I would guess that the 97.5 that was in the carb for god knows how long contributed to the clogged exhaust though.

I'm an LT80 amateur, but I've learned that when certain people post specifics on these quads the best thing to do is listen.