my sons lt 80 has a lot of mods done like 2mm oversize piston ,transfer ports,front rollers lightened,heavier rear clutch spring and clutch shoes lightened,carbon-fibre reeds .reed cage bored out , 95 main jet , but his bike is still not quick enough taking off and top end. anybody got any jetting ideas .his drive belt runs on top off a washer at the front variator clutch if i take out this washer will it help any?

 

To answer the clutch washer question,,You can do one of 2 things:: 1) grind the washer to the same size as the clutch bushing 2) order part# 09180-16043. This is the long version of the clutch bushing that was used on the older models.....This will improve low end.
Why isnt it fast? Here's my version of what I see acording to the specifics of the work in your post.
1) Boring to 52mm don't do much at all for power gained. It was a waste of 4 bores
2) Boring the reed cage is another thing that dont produce much,altho no harm done here.I make the cage flow a lil better,but I dont bore it.
3) transfer ports? What is done 'exactly"?Did they raise the transfers? Did they flow the transfer tunnels? This is a crutial part in LT80 porting.
4)Nothing mentioned about the exhaust port. This is very critical as it dictates how the motor rev's.
5) Jetting: bigger isnt allways better,and expierience tells me that lower is the way to go. Try a 85,87.5,90 main jet
FYI:My motors use a 37.5 pilot,and a 77.5 main,and will rev to 9800 rpm's,but I wouldnt go to that on your motor without alot of expierementation

 

LT, I'm definitely not trying to start anything as you know your stuff on these machines, but Rick (MacDizzy out of California) says there is an automatic power gain from going 2mm just to start with and doing nothing else. It makes me crazy[img]i/expressions/face-icon-small-confused.gif[/img] to see conflicting stories. Check it out on his site at www.macdizzy.com He also built an LT80 for his son to run at Glamis and it revs to 95 or 9800 also. Let me know what you think. By the way I really appreciate all the help youve given me so far. Bubba

 

I agree with LT80... I run 37.5 and 80 jets with premix, and with porting revs to 9800... I have found head squish clearance quite critical.
Jack, could you email me ... I have lost your address( along with my computer stolen by some low-life) Thanks...

 

Bubba, no offence taken! [img]i/expressions/face-icon-small-smile.gif[/img] I'm happy to help.
I know about Ricks page.and have talked with him some about LT80's. The basic difference between his and mine is that his depends on a pipe to make the motor run at the rpm's listed.
I have made my motors run,and run very well,on a stock carb and pipe. And will give you 5 total bores.
Do motors make HP from boring?? My opinion is that boring gives you minimal HP gain.I'm not saying that there isnt any gain,just minimal.On a 250R you will notoce a difference,84cc's,,,,,minimal [img]i/expressions/face-icon-small-smile.gif[/img] again,IMO