I recently purchased a 98 lt80 which I planned on giving to my son for his birthday next month.
The quad had not ran in several years, and was all "gunked up" in the tank/carb.

I have pulled the carb off and cleaned it out thoroughly using carb cleaner, wire through the jets, and blowing it out. I replaced the air filter with a new "UNI" foam filter. I emptied out the gas tank and had to replace the fuel pet **** with a new OEM pet ****. After opening the clutch cover, I found that there was some type of oily gunk inside the cluch area as well. I replaced the clutch belt with a new one, and replaced the crank seal on that side of the motor as well. The cylinder compression measures 110PSI.

After the above maintenance, I started the quad. It fires up, and seems to idle pretty good, but when I try to ride it (I am 170lbs) it will barely go (maybe 10mph at best). I jacked the rear of the quad up and tried to rev it up (wide open throttle) but it seems to not want to rev up as it should. Seems to fall flat at the higher rpm's.

Since my boy's birthday is coming quickly, and I would like to get this running as soon as I can, where should I start?

I purchased a carb rebuild kit and plan on taking the carb back off the bike and using the kit to rebuild it as soon as it arrives in the mail. Would the clutches create this type of problem? And suggestions to get this thing running as it should would be appreciated.
Thanks

 

If you are well away from neighbours who could complain, remove the exhaust and try it without. Also check the exhaust port, I don't know if the 80 is the same but the LT50 forms a curtain of hard carbon right next to the piston.

 

did you maintance the clutches while you had it open? are you sure its an engine problem and not a clutch issue? run it without the clutch cover on and make sure the variators are moving properly

 

Remove the exh pipe. There's a lil washer with a hole thru it. Kind of a rev/ Perf limiter
Throw it away
Do the clutch/shoe mod it helps a bunch

Lastly if that's not enof contact LT80 he is the man when it comes to fast lt 80's

I have a stage 2 built engine for my sons lt80 and it will drag my 290lb **** about 30 mph

 

I didn't check the clutches while I was raving the belt, so with my luck I'm assuming that it will probably be a clutch issue.

I will remove the exhaust pipe and see if the restrictor is still there and remove it if it is.

I'm not planning on making this thing a "rocket ship", but rather a good running quad until my son gets used to it. He is riding a 50cc right now.

What are the mods to the clutch (if any) that I could or should do based on keeping this thing basically stock.

 

I'm thinking that the grease got hard in front clutch thus boogering parts all up and a no go.
I could be wrong tho. Better take it all apart and maint front and rear clutchs.
Remove 2 rollers and take the rear clutch shoes down to 180 grams each. Smooth that thing out for the lil fella.

 

Thanks LT80, I was thinking that I should have serviced the clutches while I was in there. So, does lightening the clutch shoes down to 180 grams, and removing two rollers from the front clutch only make the clutch smoother, or are there some other benefits? I am thinking that I am going to have to limit the throttle (using the screw limiter on the throttle) until he gets used to the added power jump from his LT50. Will these mods still benefit it on low power settings.
Assuming that the front clutch assembly needs new rollers and a plate, where is the best place for those parts. Is it better to get OEM parts from the dealer, or are there better, and /or cheaper ones out there that you could recommend.

Thanks in advance!

 

Oh, one more question. Do you just grind down metal off the clutch shoes anywhere, or can you let me know how YOU would go about it. I do have a good digital scale that measures grams, so I just need to know how and where to lighten the shoes.
Thanks!!!!

 

oem is the only option as far as i know.

as far as lightening the rear shoes, and removing rollers from the front, it raises the stall speed and does smooth it out after the initial take off, but i really cant speak for what it does on a stock engine, i've only done it on a jack aka lt80 ported engine, so hopefully jack or another member can chime in on its affects on a stock engine.

i highly recommend either removing the head gasket and applying some sealant in place of it, or having the head milled .030 to raise compression, it doesnt really add a ton of noticeable power, but more makes the engine run a lot better and crisper

 

you will see excess metal on the outer edge of the shoe, where there is no friction material, thats where you cut the bulk of it off, jack knows how much to leave on there, and then drill holes in the bottom or sides to achieve the exact weight