So, I wanted to start off and say I've learned a lot from reading these forums and now have an issue I can't seem to figure out.

I have an LT80 I got from someone because they got sick of working on it. Oil pump went, starter went, key switch went, and so on. Well, he rebuilt the top end twice and it ran great. I've been running it and messing with it, greased the back up with high temp grease by using the fitting. It ran great. Now, when you're full throttle for a bit and it reaches max, when you got to slow down it makes this horrid chattering noise and will die no matter what you do. The other day when it did this, the starter would try to push it over but failed most of the time. Wouldnt make a noise. The relay would click. And I know the battery is good cause I let it sit about 10 minutes and it turned over and eventually started, but made that horrible chattering noise almost like valve chatter. Only louder. I let it sit a few days, fired right back up, went around the yard a few times and it died but started back up. Then went down the road slow and when I came back it died and chattered a lot. Started back up, but would bog or chatter if you got it moving too fast.

Does anyone have any suggestions on where to start with this?

The list of new stuff is:
Starter
Carb
Air filter
Brake cables, front and rear
Key switch
Relay
Fuses
Top end (piston, rings, cylinder)
Spark plug
And I think that's it..

 

Do a compression test.
Service the clutch's.
You'll find something wrong.
Chain/sprockets wore and skipping?

 

Thanks for the quick reply LT80!

I was going to get a compression tester today after work, AutoZone rents them.

The clutches I haven't touched, but, makes sense if they're hung and the starter wouldn't even turn the motor, right?

I don't really know what I'm looking at/doing when it comes to these clutches. I pretty much just pick stuff up and tinker with it till it makes sense. What should they look like? Smell like? Act like? And where is a good place to get parts?

Chain/sprockets are a little saggy but not as bad as my other and the noise is coming from what sounds like the case/front of motor.

Thank you again for your assistance!

 

You can get a heads up with what it all looks like at a online dealers parts fiche.

 

Fair point!

I start with compression first. I read somewhere you said above 90 and someone else said between 115-130. Should I do a cold test and then run it till it's nice and toasty warm and do another test (and try not to burn my fingers on the plug)?

 

Any test. 90 minimum. apply wot while cranking till the gauge peaks.

 

Did it both cold (100) and hot (90). I don't think that's the issue.

I took the side off the case where the pull start would go and the belt was slapping around like a fish out of water. I have a video of it idling and full throttle when it dies and you can hear the noise and see the belt.

@LT80 do you want me to upload them somewhere and send you the links? Would it help any?

 

No reason to. You need to get into the clutch's. Remove both front and rear for inspection.

There is going to be something wrong inside there. That's when pics may help.

 

Alrighty, I'll work on that here in the next few days. Having a full time job really puts a damper on play time!

Thank you for all of your help. I'll update the thread after getting it apart.

 

​​​​After looking at the front it kinda makes sense what I need to pull apart and look at.

But looking at this link here I don't really know what could be a problem or what to look at?

Any insight on what the issue could be on the rear? I don't see rollers like the front clutch.