my motor is smoking

[user101]

i have a 99' 400ex stock motor...nothing to my knowledge has ever been done to it. its smoking blue at start up and it also gets wasted by other stock 400ex's that are new. ill prolly have 300-400 dollars to use..i know that blue smoke is oil and it has been using oil. i was thinking maybe i should get a stock bore 10.8-1 piston,rings,and have some minor head work done..does this sound like a good idea????

[reconmaster]

i think ur rings could be stickin or valves could be 2 u should get a mnew set of rings maybe, whens the last time u checked and/or changed ur oil.
Get a mechanic 2 check ur motor out 4 u b4 u have 2 spend way more money than what u have.

[exatak199]

if its useing oil i would say go to a 406 b/c it will clean up your cyl.wall if you dont bore it might still burn oil after you rebild it witch would suck:p and all so make sure that you get new valve seats put it cuz if you dont oil could leak witch would make it burn oil.

[user101]

Originally posted by reconmaster
i think ur rings could be stickin or valves could be 2 u should get a mnew set of rings maybe, whens the last time u checked and/or changed ur oil.
Get a mechanic 2 check ur motor out 4 u b4 u have 2 spend way more money than what u have.

i check my oil be4 every ride and change with mobil 1 synthetic about every month

[chucked]

rings and valve seals if you want to stay reliable, 10.8 if you want to kick their ***.

[user101]

Originally posted by chucked
rings and valve seals if you want to stay reliable, 10.8 if you want to kick their ***.

well i figurd while im in there i might as well do sumthin to pep her up a little bit:devil:

[user101]

also id like to gear a little higher but still have respectable low end...wut is the best way to go 16 on the front or the 36 out back??? ive heard that the 16 was a little to tall of a gear to run with a stock motor.

[chucked]

Originally posted by user101
also id like to gear a little higher but still have respectable low end...wut is the best way to go 16 on the front or the 36 out back??? ive heard that the 16 was a little to tall of a gear to run with a stock motor.

When you say "its smoking blue at start up " I know its the valve seals because while its sitting, all the oil in the head is leaking through them. Just thought id let ya know....

IF you put the 10.8 piston in there, you will lose bottom end but gain top end, so if you do the piston leave the gearing stock, by what your saying you want. If you leave it stock do a front sprocket, easier cheaper and you dont have to buy a longer chain.

[quadmxracer]

Since when do you lose bottom end with a higer compression piston with stock gearing? You gain low end and you shouldn't lose any top end at all. But putting that bigger sprocket may make you lose a little bit on bottom.

[chucked]

Originally posted by quadmxracer
Since when do you lose bottom end with a higer compression piston with stock gearing? You gain low end and you shouldn't lose any top end at all. But putting that bigger sprocket may make you lose a little bit on bottom.

well yor kind of right, if you leave your cam stock you would probably gain come bottom end, but if you want the piston to work well you should put a better cam in it, then you would lose torque but gain power.

[user101]

Originally posted by chucked
well yor kind of right, if you leave your cam stock you would probably gain come bottom end, but if you want the piston to work well you should put a better cam in it, then you would lose torque but gain power.

im not gonna have the money to buy a cam..i know that to get the full benefits from the piston a cam would be the way to go but i dont have the money.

[user101]

i also need a good place to get, i think ?valve seats? or whatever i need to get done to the head..im proably gonna tear into it this week sometime after i call around and get some prices on parts.

im gonna use a local shop to do the boring which is gonna be very minor like a 406.

[chucked]

Originally posted by user101
i also need a good place to get, i think ?valve seats? or whatever i need to get done to the head..im proably gonna tear into it this week sometime after i call around and get some prices on parts.

im gonna use a local shop to do the boring which is gonna be very minor like a 406.

your definately gonna need valve seals, the shop should know if you need anythign else, as logn as they know what theyre doing.

[bradrenea]

Check your PMs

[DEAL]

Smoking on start up usually means your valve seals are bad.
So I'd go with new seals, a piston and cam, I wouldn't bother doing any headwork unless you bore the motor.