1990 LT80. Just got this back from the EX after it sat for six years. We had this for our oldest son and ran good before he got older and quit riding it. I drained all gas from it when we put it up. Now it's our youngest sons turn.

This bike is all stock. Oil injection still in use. It was rebuilt just before we put it up with a little time on it.
What I did: Checked air box for rodents and cleaned, rebuilt/ cleaned carb. Bowl full of oil, strange. Checked and cleaned carb. about four times now. Carb. has the plastic float in it that's not adustable Took exhaust pipe off and checked. Had good flow. Checked petcock and gas flow to carb. by prime. Checked good. Fuel line has see through filter with brass screen. It looks clean. Checked compression, read 118 to 120 depending on what guage I used. I had two so I checked it with both. Checked reeds with one having about ten thousands day light showing and the other flush. DID NOT replace orings from carb to manifold. Checked gas cap by running it loose. Checked good.

What it's doing: Starts rite up by choke by touch of the button, wow. When I take the choke off it will idle about five seconds and then fade off and quit. I can keep it going by just flicking the choke. I definetly can keep it going by leaving the choke on. It will idle all day until I take the choke off.
I will tell you, I am no carb. man. But these appear to be simple devises. I just spent about four hours today cleaning it just to make sure I didn't miss anything.
What am I missing. Any input would be appritiated. Thanks.
Sorry. I should have put this in the kids quad area.

 

It's a Zuki..Your in the right area.
For some reason, there has been a hard time cleaning carbs this year. The end result was to boil the carb to get the gunk out. This is something you may want to try.
Other than that, it sounds like the main seals may be leaking. That would explain why a lil extra fuel (choke on) helps. You can spray carb cleaner around the front clutch and the stator to check.

 

check pilot jet. and make sure your air filter is charged and attached properly. sounds like a lean mixture somewhere.

 

lt80 and newporthillclimber, thanks for the help. I'll be checking that stuff tomorrow.

 

Well, I got it to idle. I sprayed wd-40 around the main seal and carb. manifold area and no change in the rpms. So off went the carb. again. I really focused on the pilot jet on this round. Took the pilot jet out to make sure all was well. Every time I put it back in it didn't look quite rite. Got curious and dug up my old pilot jet and installed it. Looked good and clear. ODD. So now it idles but bogs when working the throttle. I'm going to try some other stuff later this week.
I can't quite figure out how to remove the main air jet (2). There is no prervisions for a screw driver that I can see. Does the needle jet need to be removed for cleaning and how do you remove it.
Thanks for all the input.

 

Air jet???
Do you mean the main jet? If so::if the main jet does not have a slot in the end, it's not the original jet.
Use pliers to remove it.
Original main jet size is 92.5 but a 87 and or 90 main should work fine.
Needle jet?
2 jets, pilot and main. there is no air adjustment.

How ya spend 4 hours on it and not remove the main jet? j/k
If you allready didn't, remove the float needle seat and clean.

 

LT80, what I mean is by looking at the carb from the front, air cleaner side, there are three holes if you will at the bottom of the throat. In my book it shows an illustration of removal of what they call main air jet 2. It's the third hole on right of bottom.

 

That must be why I have no book..They just confuse me..LOL
In 16 years of LT80's, I've never messed with any of those holes.

 

I'll be honest. I do learn more here than from the original suzuki service manual. The break down illustrations are some what nice. Forums are very nice. This one as well as others. It's amazing on how much time people take out of there time to help others through forums. Thanks.

 

Same here... LT80 and bigdog04 you just saved me a lot of hours