Hello everyone,

New to the site and may I say, man there sure is a lot of knowledge on here! Good to see.

Well I got my 6 year old a 89 LT80 that has probably sat for a good number of years from an Uncle of mine. And let me just say he is not the best at maintaining his bikes. This thing is bone stock but I really want to get this thing running good for my Son. He is pretty aggressive and needs something that will move well in the desert and the dunes. Anyway I got this think all torn apart and am going threw just about everything...

Flywheel was reall rusty...cleaned and check the stator which looked fine.

Cooling fan is missing fins and it looks like it was rubbing up against the platic cover, which will also be replaced.

Removed the Clutch inspection cover only to see that the belt probably needs to be replaced.

So by now you all probably know that this thing needs a good goin' threw...my question is would anyone have any other suggestions at what else I should look at??

How about the Oil pump, is failure common there? The Carb is stock and I am not 100% sure its good. I don't mind leaving the injector system on if it works fine but don't mind blocking it either.

I also noticed that the Clutch could be an issue, any slight mods I could do there to increase performance?

Thank you very much for any input!

Cheers!

 

Welcome to the forums. [img]i/expressions/face-icon-small-smile.gif[/img]
You need to do clutch maintenence. Remove the clutch cover (not the pull start hole cover) and remove both clutchs.
Front: check for flat rollers,hardened grease,and gouges.
Rear: check for bad bearings. You can take the rear clutch shoes down to 180 grams each. That'll help the take off. No other clutch mods will get you much if any with a stock motor.
When you take the cover off, you will notice a black plastic piece on the end of the crankshaft. That's what drives the oil pump. Now is the time to decide injection or mix. Simply leave that piece out if you want to go to premix. A synthetic oil at 32:1 works well.
Nothing wrong with the stock carbs other than needing a good cleaning usually.
Gidday. [img]i/expressions/face-icon-small-smile.gif[/img]

 

Thank you very much LT80 really appreciate it. I will do that this week trying to get the bike ready for our first trip next weekend....man I am cutting it close. Goinig out to Ocotillo Wells for the weekend.

I am going to remove the injector system. And now that I have torn into this thing...I have some other questions.

I have everything off the bike carb and everything out from there. I did a quick compression test (without the carb on) and I got a reading of 70psi. This would still be a good reading right? Even though the carb is off. And I no 70psi is not where the compression should be.

My thinking is, since the cooling fan was not working correctly the cylinder may have reached the upper temps and fried the rings??? You think that would be a correct assumption?

I guess I will take the cylinder off tonight and see what up there. I am thinking this cylinder has been messed with. Should I just re-ring it or do piston and rings?

Thank you very much for your input...my son is really excited about this thing hauling some but.

Cheers,

Dunedawg

 

Happy to help. [img]i/expressions/face-icon-small-smile.gif[/img]
70 is bad period. You will need the next size piston/rings and a bore. Should be 120 or so.
The carb off is no issue cuz you test with wide open throttle.
The fan prolly had little to do with the piston. I think it's just wore.