Hello -

So few years ago I rebuilt my top end and did a clutch mod on my LT80 thanks to all the help from here (Jack).

Now, I have a new problem. The quad ran great, but it has now sat for about the last year. I went to start it up and battery wouldn't take a charge. So after replacing, I got the old girl running again. I had the problem that many others seemed to have - would only run with the choke on and was "sluggish" at best. It really screamed before...I assume dirty carb and bad gas.

So I drain the old fuel and take the carb apart and clean the jets etc. Carb was pretty clean, but I think the jets had some gunk in them. I get it all put back together and on the quad and have developed a new issue. It will start up, but it revs all the way up. No throttle control. (Note to self - this gets very exciting, even with the brake set. My neighbors probably had a good laugh or think I'm a complete idiot! Luckily, no damage and no injuries, I got to the key quick enough as I chased it across the driveway.)

I mess with the throttle screw, cable and no luck. So pull the carb again, reinspect and reinstall. Still the same thing.

I even pulled the cable and needle jet out from the top of the carb. It still fires up and runs wide open with no throttle mechanisms attached.

I'm thinking I have fuel free flowing into the carb, maybe from a bad needle and seat?

Any thoughts/ I'm done with it for the day and will probably tear into again tomorrow.

 

When the carb is in your hand, with the bowl off, I blow thru the fuel supply tube and work the float to get an idea if it's working.
You sure you got the slide in correct? It sounds like you got it in backwards thus it's not going to seat thus high rpm's..

 

I've had that problem before as well and it was (like lt80 said) due to the fact that I had put the slide in wrong it's not hard to do lol. Best of luck with the troubleshooting!

 

Well it turns out it was the throttle sleeve. I had it in backwards, all three times I tore it down. I really thought I had switched it in my trouble shooting but apparently not.

In thinking about it, all the pulling of the sleeve and throttle linkage just gives you wide open throttle, so that's why pulling the sleeve and throttle needle gave me the same result.

Now she runs strong again. FYI - when I did my rebuild, I shaved the head .030, bored .030 with a weisco piston and did the clutch mod with new clutch rollers. I got good results and a lot of power increase from this (especially on a motor that was low compression).

Thanks for the help.

 

I'm not an expert but I will agree with lt80 because it happened to me no the lt-z50 i'm working on. There is a notch cut out on the bottom of the slide and if you look in the port where the slide goes into you will see the piece where that notch is suppose to fit over. Good luck on the fix and let us know if it helped.

 

Lt80, can you tell me the float height on a LT-z50 atv, been looking for an answer but no one seem to be interested in answering me or I'm to impatiante.