View Full Version : need help on lt 80

iceman 22
12-12-2006, 05:07 PM
i have a 2005 lt 80 changed top end to upgrade. Installed a barely used cgr port and polished cylinder and window cut piston. The head is shaved also bought it from member of this site. Well i also installed a 20mm carb and filter. The problem is that it won't start now. It seems like it wants to but doesnt. I pulled apart and checked the gaskets they both are new . Retightened the head and still nothing. also put in a new plug it is br8hs plug . Checked carb and has flow from gas tank. Any help would be greatly appreciated. Thanks i'm new to the lt80 game.

12-13-2006, 07:45 AM
Did you do all that at once?
A ported cylinder needs a highly modded head. A shaved head alone will not do (99.9% of the time).Check the compression...
If all is OK, then put the stock carb back on and see if it runs.
The 20mm carb is not great.
What did you do to the clutchs for that motor?

iceman 22
12-14-2006, 11:17 AM
i bought the set up from big boss on this website. It came with the cgr port and polished cylinder and shaved head. I have boyseen reeds , fmf pipe , k&n filter and removed two rollers from clutch that;s the only clutch mod. I think the problem lt 80 is in the 20mm carb. It keeps flooding the cylinder for some reason or another. I drain the cylinder as best as i can and it does it again. I know it won't crank with raw fuel in the cylinder like that. It also is leaking the fuel out where the exhaust attaches to the cylinder. What would cause this new carb to do this? Thanks for the help in advance. Also the window cut piston came with the cylinder.

12-15-2006, 07:38 AM
OK, then the head would be fine. It's more than shaved. :)
The float needle may not be seating on the 20mm carb.
Does it do it while sitting overnite or immediately while working on it?
Do you have a fuel shut off or do you put the petcock in the run position while sitting? (run is off)...

iceman 22
12-15-2006, 10:05 AM
lt 80 it does it while i'm working on it. I called dg and asked them and they said to put the petcock on on not prime. Lt80 hop-ups told me to put it on the prime setting always, i think this is why it was flooding so much. I'm gonna try to drain the cylinder and put the petcock on the old setting like a stock lt80 carb and see what happens. Also lt 80 the piston only had 5 races on it so i didn't change the rings do you think that this will be a problem or is it already contributing to my starting problem. I also noticed a little slack in piston but not much. P.s. this bike is a trail and dune bike not really a motorcross bike. Lt 80 can you verify for me if 10.25 shocks will fit on stock aarms lt 80 hop ups says yesbut i'm not sure because stock is 9.75. Thanks for everything . I have wheel extendeers on front and back.