Forum Members: For Christmas I purchased a 1987 LT80 Quad for my boy. It was not running when I acquired it, so I performed quite a bit of engine and electrical work (honed cylinder, replaced rings, seals, etc). The motor runs quite well in low end and mid-range, yet at full throttle it looses power. A plug read shows good color; no signs of fouling. Also, the carb leaks fuel constantly. Any suggestions before I go out and purchase one new of everything would be appreciated. My son is wondering when he will be able to ride his Christmas present. Thanks, Folks.

 

Have you taken the carb off and given it a good cleaning. If not do that first.

 

I agree on the carb cleaning. Remove the lil phillips head screw and remove the brass piece that the float needle sits in and clean thouroughly. Remove both jets and clean also (don't loose the lil black piece thats below the main jet).
Whats the compression? (I understand you freshened it)
If the carb don't fix the top end problem, I'd look in the front clutch's for trouble.
Keep us informed please. [img]i/expressions/face-icon-small-smile.gif[/img]

 

Thanks for your reply. Yes, I have removed the carb a number of times, checking condition, cleanliness, and functionality. I am wondering whether or not the float needle can simply wear out, causing carb top-end problems. Since I do not think that it is normal for the fuel to constantly leak out, I am wondering if the float needle is not seating properly.

Thanks again for the help.

GeeMan

 

Thanks for the reply. Compression is good; I do not remember exactly but the fellow who performed the test will be able to tell me later tonight when he stops by. As for the float needle, it is clean, but I cannot tell if it is worn. I have tried moving the jet needle both up and down with no impact on this issue. Like I stated, the plug color is a nice brownish tint, no signs of fouling or an excessively lean mixture. Could a failing coil produce these symptoms? Or would I see fouling at the base of the plug if the coil was not firing at top end? I am ready to deep six this carb and purchase a new one. On the other hand, I am not sure it is truly a problem with the carb. Any advice from you gurus would be greatly appreciated.

Thanks again, GeeMan

 

Certainly the needles can wear out. They're moving parts.

For the float needle: Check the needle and seat where they meet. There could be a small worn groove in the needle and the sealing rubber should be in good shape. Make sure to set the float level properly, too.

For the jet needle: The taper should be smooth with no wear spots on it. If it appears at all worn, replace both the needle and the seat, as they wear out together.

Both of these could cause it to run poorly, btw.

 

He's right, check for that lil groove around the needle. It very well could be worn.
FYI: there is no float level adjustment.

 

Just got a call from a guy having similiar problem (fuel running out).
I do remember having a petcock problem before.The fuel would run out the hose when in the run position (which is actually OFF when the motor is not running).The fuel should not run out till vaccum is applied to the 2nd hose (in run position). I had to blow back thru the fuel hose. This fixed one machine and not another (bad petcock). Check the petcock and see if that may be it.
I run a fuel shut off valve (dollar item) on most of mine.

 

hi i just got a suzuki lt80 from a guy it has problems the shut of for the fuel was messed up so i put a shut of on it the vacume lines are off the carp cant figure out how they run.it has good take off but when you hit it hard it boogs down almost dies tryed everything please help.thanks jim

 

LT 80
I have a 2001 LT 80. I have removed the restrictors, Installed a DG pipe, Installed Reed Valves, Uni Air Filter, and wheel spacers. My daughter weighs 65 pounds and this is still a dog.... What is the next move with out affecting the dependibality of the bike????
Thanks for your help.....


Webb [img]i/expressions/face-icon-small-happy.gif[/img]