Hi, I've been working on my sons lt80 off and on for few months now. I've been following most of the recommendations I've found here, thanks by the way, and I still have an issue. I removed 2 front rollers, then cut rear shoes and drilled to 180g, but still doesn't have a good stall or take off. Soon as you hit the throttle, it takes off. It has plenty of power, just with me on it if I stop on a hill it really has hard time taking off. My boy weighs 50lbs, but it still won't spin, or leave with authority. So I got an idea, I lightened shoes to 170g, then wouldn't move. So I'm back to 180g and all is the same, I also put all 6 rollers back in, no noticeable difference, except top speed.
Please help, thanks for reading.

 

Compression?

 

Aha! We were thinking alike, I did a compression test on it and I'm getting 90psi. Kinda on the low side I think. Could that be my problem? It starts right up on cold mornings, and runs good so i didn't think about it really till today.

 

90 is minimum but it should be fine.
I'm wondering if the pipe is plugged.

 

Well I removed plug like posted on here, it revs out fine, top speed about 25ish, doesn't seem it but if it is what can I do? It's a 93 if makes a difference, I'll take comp again it's been a mth or so and few good rides in between. It seems to blow pretty good thru both plug hole and tip, but still could be. I've never removed pipe from engine could the restricter still be in play? I'll look just kinda scared to remove the nuts off studs pretty rusty. Thanks a lot Lt80 I've been following your advice for mths now and just finally got nerve to make my own profile, there's been a few times on different rides I could've helped, so now lookin forward to helping.

 

Ok, to go thru this again, 90psi comp, new reeds, uni filter, I removed pipe and air blows thru it easily, but I heated it and burnt out some carbon, not much, blows thru easy as before. Clutch shoes 180g, front has all 6 rollers, removed two once no difference just lost some top speed. I'm still not getting any stall, if sitting and idling, just touch the throttle and it moves, if you nail it it goes ok, just no revs till moving good, even with my 50lb son. Has no problem goin with him, just I was expecting more, most people seem to be night and day difference, mine is same as the shoes being the 216g they were. Sorry so windy on this, but I'm guessing it'll have to wait till I get fresh bore. I bought pro x piston, and gaskets, getting head shaved .030. Then I'll let you all know. Thanks again.

 

Are all the restrictors removed? they came with 3 limiters, a disc in the exhaust, which you would have seen when you removed the pipe, a spacer in the carb, that keeps the slide from going all the way up, and a washer in the secondary clutch, which keeps the top speed down by not allowing the sheaves to fully close. Take off should be better, though, when I played around with my son's LT80 years back, I opened up the reed cage, it is very narrow, I ran 4 rollers in the front clutch, never touched the secondary except to give it a good cleaning, it was all gummed up and not working real good. I rejetted for the intake work, and that thing would spin and throw dirt all the way up a hill with my son on it. It did have a rebuild and a .020 over piston in it, that could also have been a factor.

 

I've had carb apart for cleaning, didn't see the spacer on top of slide to stop travel, there wasn't a restrictor in the exhaust inlet, and when had the rear clutch apart, I don't remember a washer, just shoes, and drum, but didn't pull apart any farther than the shoes.
I just think engine is weak, I've got piston kit, just have a ride on Good Friday the 29th, so it'll be coming apart after that tho, thanks and maybe I'll have to take apart rear again and look for washer.

 

I might see if there is rust/yuck on the stator. Sometimes they need to be sanded to clean them up
.
Don't pay 95wolv no nevermind on the rear clutch. While I was stealing parts from his ride, I added a shock absorber washer off a 1979 Ford LTD to his rear clutch to confuse him.

Altho a new piston is a great idea, I'm not convinced that either the carb or electrical can be ruled out.

 

Ok I'll give it a look, it's worth the time, oh forgot to mention I pit the 90 main jet in it also.
But I will certainly give the stator a good inspection and cleaning. Thanks again