The kid rides an LT80, recently put a little $ into it: bored to 51.50mm, new piston, rings, top end gaskets, carb kit, KN filter in stock box, Boysen reeds, new petcock. Here the problem, every time I start it cold have to remove the tube from the front of the carb and block it off with my hand. What gives? I spose these carbs can wear out! Also would like to pick up some more snort! Whats the best/least expensive mod. Mill the head 30? Thanks for the help!

 

One more thing, what about a 10 tooth front sprocket, it'll pick up top end but will it be a dog out of the hole?

 

180 grams on rear clutch , mill head. really brings it to life. if moore [img]i/expressions/face-icon-small-wink.gif[/img] is needed get it to jack!!!!! as for the hand choking never had that problem. your turn lt80

 

The choke circiut is obviously messed up. I'd clean the carb. When it was apart, did you remove the choke plunger and clean in there?

Stock gearing is 10/22 (520 chain) cept for the older ones with the 428 chain, those are 12/26

 

When the carb was apart it was cleaned well, but maybe not well enough, will try it again.

I read in some of the other posts that some of you get the lt80 to rev to around 11-12k rpm's, how? Will a pipe and some port work make this big of a change?

Looking for good all around perf. what would the recommended spocket sizes be?

Thanks guys!

 

The holes in the carb are very small. Sometimes it takes a cpl times to get it all. Use compressed air to blow all the ports out if possible.
RPM's:: Yes, it's all porting and the choice of a pipe. That's the quick answer. [img]i/expressions/face-icon-small-happy.gif[/img]
Sprockets: for a stock motor, going up a tooth on the front is possible.

 

Where would be a good place to get the spockets, are the LT80 only parts or do they fit others?

Thanks for the info.

 

If you have the 520 chain size (10/22) you can get a 11 tooth yamaha blaster sprocket.

 

Would like to change the chain and go with the 480.