Hey LT80,
I bought the cylinder set from you so I don't know if port work was done. No sweat on the bearing, we're square. I'm happy to get your help and parts. I'll try lowering the needle one notch. What does that do? Tractor Suppy suppose to have #40 and If I can find a 14 tooth I'll try it. Thanks

 

Ok, Thanks.
Yep, wish I would have done some port work.
I do know the head is shaved.
AS far as the bog, Still running all 6 rollers?

 

Hmmm, "Bog" "rollers" you'll need to educate me please.
Didn't know head was shaved. That'll add compression right? A good thing.

 

LT80 , I'll send you a PM.

 

After doing some poking around, "rollers" it seems refers to the clutch rollers? I don't know if there are 6 or less.
When I tear it down, should I use less then 6 rollers????? what would be gained or lost? I'll search for more info
and try figure it out. Perhaps I can find a diagram. Thanks all.

 

The "rollers" on a centrifugal clutch determine at what RPM the movable sheaves engage the belt pushing you forward. The "stock" set-up has 6 rollers and engages pretty quickly...but that's aligned pretty well with the stock motor making it feel torquey down low with a decent top end.

If you modify the motor (porting/stroking/other) then the power & RPM ranges where you make the most power also change...thus requiring a change to the weights (rollers) in the primary & secondary. Removing weight means you need to spin the clutch faster (more RPM) to engage with the same belt force as if there was more weight...modified motors will spin higher in the RPM range so the stock clutching will need to be changed...

In a stock motor removing rollers will just increase the RPM at which the clutch engages...good for the hole-shot, but because you have the same overall RPM to work with you will suffer some in top speed...

 

Excellent Jack. Thanks for taking the time to explain all that science to this rookie. Greatly appreciated. Only motor mods is the top end I bought from you and That was a bored cylinder, possibly shaved. Then I added new gearing and chain.
Now that I understand a bit, I'll play with rollers see what we get.

 

I’m looking at buying a 1999 LT80 and the current owner says it’s hard to start. He says the petcock is broken and that to get it running he has to take the spark plug out, blow the gas out of the top end and put it all back together and then he said if cranks for a little while and starts up. Does this sound like a simple replacement of the petcock and possibly a carb rebuild? To me it sounds like engine is flooding out while sitting and then won’t start due to this. Would love some input as he’s only asking $500 and I’d like to see if it’s worth that or maybe offering $400.

 

You are correct, it's flooding while sitting there. A arb cleaning would be in order. I install a on/off valve next to the carb. Shut it off and let it run dry. No more flooding. Also, Ethanol plays a big part in the flooding.
Buy it.

 

Hollywood, if I had chance to buy an lt80 for that price I'd be all over it. Then I'd read these threads for fantastic help. LT80, Dirtdevil and many others know their stuff. If it weren't for them I'd have a yellow yard ornament and grandkids would be playing video games instead of racing. My hats off to you all.

p.s.
As lt80 advised I added an inline on/off and a small inline filter to manage fuel. Last week I bought the recommended Banshee petcock (direct replacement), works perfectly.