My son's '87 LT80 is making a bad noise - most likely an upper (hopefully) or lower (hopefully not) rod bearing. I'm going to tear into it and rebuild it. While doing so, I thought I might as well try to get some more power out of it. What I'm looking for is an intelligent combination of performance enhancements.

Things I've considered are:

-Possible big bore kit (105cc). Is it worth it?
-Exhaust pipe. I've heard Trinity is good (Dr. Q recommended it, plus I think "LT80" has endorsed it.) I'd like to hear opinions on best bang for the buck, versus best overall if money were not a factor. Are LRD systems good? They sure are expensive.
-Porting. Who has a decent port map for this motor, or are they best left in stock trim with just a clean up? Interested in having reputable person port it, otherwise I'll clean it up myself.
-Piston. Are there any piston tricks? Sometimes 2 stroke engines (and upper rod bearings) can benefit from pistons being ported as well, and lightened (if vibration is an issue). Is this the case with the LT80?
-Carb. I've seen a 20mm carb kit available. Is it worth it? What other mods would it be good with.
-Reeds. Are there any decent aftermaket reeds and reed cages? Are they any better than stock?
-Chain. Being an '87, it already had a 420 chain and sprockets. I've replaced the chain with a #40 chain which is cheap and has even less resistance. Are the chain tensioner kits actually needed? Mine feels pretty good - not too much play. I'm also changing the front sprocket to a 13T for a little more top end speed for driving on gravel roads.
-Clutch. I've heard of a mod that can be performed to the stock clutch. Details. What does it do and how do you perform it? What will the stock clutch hold up to as far as the other mods I've listed? Any aftermarket clutch kits available that are better?
-Chassis. Currently, I have 2.5" wheel spacers on all four corners. It was a cheap way to gain stability, but I'm interested in a double A-arm conversion (possibly from a quadsport 230). If anyone has done this, let me know your thoughts. Any shock recommendations for more travel?

It sounds like there are some intelligent LT80 quadsport guys on here, particularly "LT80". I'd really like to hear your comments. My son is 10 and getting pretty big for the 80. I could move him to a bigger quad (230E or 230Q-sport) but I really like the safety of a 220LB quad and I know they can be built to perform with (and even above) much larger and heavier four strokes.

 

Thanks for asking. You will save hundreds of dollars cuz you did so.
I'll answer what I can. [img]i/expressions/face-icon-small-smile.gif[/img]
Big Bore: Worthless. CC's don't mean speed.
Pipe. The Trinity is what I've come up with after testing. LRD is a good pipe but like you noticed big $$$. I have heard about the LRD breaking from hard riding. It's a lil big and cumbersome to handle the vibration,etc.
Piston: stock is best. Some put a hole in em. I've done it both ways with no difference.
Carb: 20mm.. I can get a stock carbed motor to rev to 12k+. No reason to waste money there.
Reed: Yes they help.
Chain: The 13 front should fit the chain perfectly. A tensioner is a good idea if needed. There are quality chain adjusters available. Prolly not the one your thinking about.[img]i/expressions/face-icon-small-smile.gif[/img]
Motor work: You can clean it up youself. Porting should be done by someone that is expierienced. I've fixxed many a "home brew". LOL
Clutchs: for a stock motor there are a cpl things to do. As far as with a ported motor, the clutchs need to be made for the motor. A complete motor/clutch kit is what you need.
You piece that guys motor with anothers clutchs and the like, will drive you nuts getting it to work.
Hope that helps some. [img]i/expressions/face-icon-small-smile.gif[/img]

 

I have a lt80 that lt80 (jack moore) has built. you have to remember that Im building it for my son. but since hes only 2 1/2. Im riding it. Im 6 foot 2 and 300 lbs. and let me tell you its a blast. I have two lt80 and have yet a chance to race them side by side. but I know the true winner. give jack a call 1(814)922-7470. he is a great guy and give you all you or you son needs for performance. you will probly be looking for another one for yourself. im now saving for jack to do the other one. you ship him the whole motor and he returns alot of smiles. please call him you wount be sorry
as for the duel a-arm set up. I had the dimond j set up and it sucked. stick with the stock or extened set.
hope this helps

 

Thanks for the responses guys.

Jack, I will probably be calling you at some point to discuss options.

 

you wont be sorry. very stand up guy and knows his stuff. great guy to work with