View Full Version : Gas/Carb problem LT80

03-04-2007, 02:55 PM
Son quit racing these things & moved on to 300EX class, so I thought all my headaches were gone, now daughters LT80 is taking my time.........Anyhow, it has set up for about 3 months, gas smells bad, 1. so i drain tank and add new gas, 2. pull line off carb and open valve.....steady stream of gas, 3. open drain screw and gas drains out bottom of carb......4. shoot a little starting fluid in it, ..... fires right up and dies, no gas is getting to the carb............ vent hose?.........trash in carb? ..... think I need to pull carb, blow out and start new,......... (oh by the way LT80....thanks for all the old help)

03-05-2007, 08:57 AM
Sometimes you have to hand choke it. I've never figured out why.
Use 2 fingers to block the air from the carb and see if that works.
Maybe a squirt of oil in the plug hole to lube/seal the rings.
Lets go from there. :)

03-12-2007, 09:38 PM
Hey guys, I have the same problem with my son's............it was mine years ago. It was sitting for YEARS. I cleaned the carb with carb cleaner (removed jets and everything)blew it out with compressed air, drain old gas. I had the filter off sprayed starter fluid in the carb, choke on and turned the idol up. It would run for 5 seconds then die. Wouldn't even start without the starter fluid(I imagine because it's way to lean without the filter). Put the filter on it, it would start without the starter fluid, but only run for a few secs then die. I'm no expert, but I think the problem is lack of fuel. I really don't want to take it to the dealer because I'll get charged out the butt plus the bike needs plenty of other parts too. I'm on a budget. I also took the fuel cock apart and tried cleaning it.......how do I know the fuel cock is working properly? When cleaning the jets.....I thought I had them clean. Should the hole in the pilot jet be smaller than a pin?

03-13-2007, 10:21 AM
Squirt a lil oil in the plug hole to raise the compression. See if that helps it run.
Turn the petcock to prime. Fuel should run out. In the On position, you can suck on the vaccum line to see if that is working.
Yes the pilot jet hole is small. :)

03-13-2007, 01:00 PM
When I turn it to prime gas flows well. I'll try the oil. With the pilot jet, I just wasn't sure if it was clean..it was so small!

Thank you:)

Boss? did you get yours running?

03-13-2007, 01:39 PM
I haven't touched mine in a week, but I will get it running. Just too lazy to get out there and get started. Then I want to trade it for a Honda 90, girl's legs are growing.

03-13-2007, 07:07 PM
Came home early, removed carb, tore it down, blew cleaner and air through all the jets and holes, reinstalled, shot a little starter fluid in the front, it took it a while, but it finally primed, and ran just fine. Thanks for the info Jack! Just had to quit being lazy and do it. Last LT on our place, ....looking for TRX 90..... Thanks again!

03-15-2007, 08:54 PM
I gave it a squirt of oil and it ran for 10 secs, but the idle was up and down. It didn't start back up after it died. I'm going to try the ole Water Dissplacement attempt #40 trick to see if there is a leak between the carb and the spacer......I'm not 100% positive that the o-ring is not slightly off when I tighten the carb. I guess this could cause my problem?

uh yeah, if i give it any throttle(while it was running for the 10 secs) at all it starts to die.

03-16-2007, 09:15 AM
You are sucking air somewhere thatís the irregular idle. Once you get to idle warm it up and get the most RPM out of the air screw and see how many turns itís out 1 to 2 is good less than 1 pilot to lean more than 2 pilot to rich.

03-16-2007, 09:47 AM
I agree there is a leak.
There is no air screw tho. :)

03-16-2007, 10:58 AM
oops sorry, your right Jack.............. I just went through that with Kyle's 28mm on his 90 e-ton sorry it just sounded to familiar thought I could help, believe me I know all to well how frustrating it can be when they don't run right. :mad:

As soon as some more leafs grow back on my money tree I'm going to do some stuff to Kyle's KFX 80.

You don't spit in the wind and you don't mess with Jack on the LT / KFX 80's lol lol ;)

03-16-2007, 08:52 PM
Hey just wanted thanks LT80, etondaddy and BIGBOSS......I appreciate all the help!!!!!!!!!!!!!!!

She finally came to life after 10years!!

I took off the carb again cleaned the carb spacer on both sides really well and the manifold. Took the head off just to see what condition the cylinder and piston were in and everything looked fine. Put it back together, hit the start button...turned but didn't start....took off the vent hose blew in it........wanted to see what would happen if I sprayed some carb cleaner in the vent hole.............left hose off.....hit the starter ...gassed it a couple times and she started idleing fine!! Even drove it up and down the street just for the fun of it. Just need to get some brake cables and extract the broken rear break bolt and let the kids at it.


Dumbass Inc.
09-24-2014, 02:28 PM
[QUOTLT80LT80;2756151]I agree there is a leak.
There is no air screw tho. :)[/QUOTE]

Hey, LT80. I recently got my kids a 87' Suzuki lt80. Has carburetor problem. I was told you were the guy to speak to. Are you still around? It will only start with my fingers blocking the carb. Then dies if your not gunning it.

09-25-2014, 06:22 AM
Welcome to the forums.
I suspect low compression but a good carb cleaning is always in order. :)