i got home from work tonite and found my kid bought a 1987 lt250 for 250 dollars.......it runs but as soon as it starts it revs up high.....where should he start????? anyone know the best carb settings and jets for mich trail riding????

looks fairly stock..........

 

does tha rpms go down after it idles for awhile?

 

havent let it run long enough.....it revs up high..

somethings up with carb(stock)..wont suck gas.....squirts a little fuel through air cleaner not ether...and it fires right up on first or second kick...havent let it run long enough to see if it will even stay running

carb to cylinder boot looks ok....reeds look ok.....

 

The engine is revving because it is starved for fuel. Take the fuel line off the carb and make sure it flows. If that's OK, remove the carb and spray carb cleaner through every hole and thoroughly inspect the rubber boots. Remove the float bowl, spray in there too, and check what main and pilot jets are in there. This website has a carb schematic that will show you how everything goes together and the stock jetting specs. Nobody can tell you what jetting you require, start with the stock settings and go from there.

BTW, $250 is a steal.

 

Would a rip in the intake cause revving like this?

 

If by intake you mean the carb to cylinder boot, the answer is yes.

 

Thanks sam,
I just bought a quadracer that had a ripped boot/intake. Good to know it would pretty much be impossible to not notice the problem.

 

I have an 87 lt 250 and the other guy is right it is just reving like that because it is starved for gas

And if that is the only prob he got a heck of a deal. I paid 2000 for mine and that was before I put any upgrades on it

clean your carb real good could have some trash stuck in it

 

ok we took apart carb, yes it was nasty.........cleaned it well......main is #360......started it up it idled for a sec or 2 then kept climbing.....then kill switch wouldnt work or pulling the plug wire to shut it down..had to lean the machine on it side to get it to quit....dont want that to happen too many more times.

there are no rips in the intake boot.....


does anyone know how the floats should be set or the needle clip setting???the float arms to the metering valve doesnt look proper

found out today that the machine was at one time from colorado..High Altitude?????

 

I also had this problem. Twice actually. The first time was a melted vent live off the carb. The second time was an air leak in the motor. If you can't find a problem with the carb, you should take the motor to a local shop and have them do a leak down test. Worst case is the motor has to be rebuilt with new seals. At that time new crank bearings wouldn't be a bad idea. Either way your son still got a killer deal. The frame alone is worth $250 if it is in good shape. Good luck