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Gary Kozdra

Suzuki LT80 bogged down with throttle open

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I rebuilt the top end, rebuilt the carb, and replaced the reed. Starts, runs and idles but has no power.  Cant barely move itself with no one on it. Air filter ok. Sounds like its bogged down with throttle open. Compression test showed 140 psi. Plug looks good. Gaskets look good. Im lost. Any suggestions??????

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@Gary Kozdra I split your post from the older topic you posted in and started this new topic for you within the Suzuki ATV forum so you can get some assistance. What year is your LT80?

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Update.

I removed exhaust which may or may not have made  a difference. 

I opened primary case to inspect clutches.

Front clutch looked ok but there was alot of grease in it. Cleaned a bit and reset rollers. Rear clutch seemed not to engage well. Spring wasnt extending fully it seemed I opened it and took the sheen off the contact points and reassembled. Belt looked ok. Ran with primary open and it seemed better but still not enough power to move the bike with weight on it. Still lost. 

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I have a similar issue with a 1999 lt80; It runs fine until the engine is really hot; then we loose power and eventually it won't stay running. My gear-head friend says he thinks it's an air-leak once it expands. We're going after it tonight with a can of carb-cleaner to try and find/confirm it. We had replaced the carb and put a cheap knock-off topend kit on it (some yahoo had run it without an air-filter and killed the head).

ALso had a sticking clutch problem as the rollers were flattened by the previous owner (maybe a fat/heavy person killed it). That was an ebay purchase.

If you have any success, please share.

-Tks

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Forgot to add that we pulled the air and fuel filters/replaced to make sure they weren't starving the engine. Also, killed the auto-oiler and just started mixing oil/fuel to better control the mix. All the gaskets are new with the exception of the carb-gasket (little plastic one) which might end up being where the issue is located.

 

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I reassembled the clutches and primsry case. Rollers looked good. Just the slightest flat spot on a few of them. Belt was good. When i ran it open the front clutch never seemed to expand but i think its bc the motor didnt spin fast enough to engage it. With everything except the plastics back on it starts and idles fine but with full throttle barely moves the wheels on jack stands.  All gaskets are new. Compression is great. Only thing odd i noticed is motor doesnt sound completely normal and the air temp out of the top end case seems hotter than usual. Im thinking about rebuiling the top end again even though its new. Thought ring clearance was good but maybe its too tight?? Might try a new plug too. What's the best plug to use here??

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