valves or rings?

[justin1022]

i was wondering what is wrong with my quad i think its valve seals but was just doulbe checking it smokes on idle then from idle to about 3rd and quites and sometiems it dont smoke at all its weird i just put hot cams stage 2 in it too.

[Hondamaster5505]

I think your problem is the cam.

Your bike was probably getting a little aged and close to being tired, but still had some life left.

By adding the cam, without a high-compression piston, that actually makes you loose compression. So the cam just lowered your compression that much more, almost making it tired in a sense.

That's why the piston and cam make a great combo. Stock compression is only 9.1:1, so with the cam it's even lower than that.

A stock 400ex should be making somewhere around 100-128psi. Yours was probably a little over 100, and the cam cause it to drop below that.

[drew416ex]

Originally posted by Hondamaster5505
I think your problem is the cam.

Your bike was probably getting a little aged and close to being tired, but still had some life left.

By adding the cam, without a high-compression piston, that actually makes you loose compression. So the cam just lowered your compression that much more, almost making it tired in a sense.

That's why the piston and cam make a great combo. Stock compression is only 9.1:1, so with the cam it's even lower than that.

A stock 400ex should be making somewhere around 100-128psi. Yours was probably a little over 100, and the cam cause it to drop below that.

I dont know that that should make it smoke though. I do believe in changing pistons when you get a cam, but I dont see why it would make it smoke. Usually if its seals it smokes off of start up. Since its doing it at idle I say its rings.

[justin1022]

Originally posted by drew416ex
I dont know that that should make it smoke though. I do believe in changing pistons when you get a cam, but I dont see why it would make it smoke. Usually if its seals it smokes off of start up. Since its doing it at idle I say its rings.

ya you se i thought maybe since i put a new cam in and i didnt do valve spring or anything maybe it was working the valves hard and the seals went but i am not sure...

[bigballz400]

put the old cam back in and see if it still smokes.....only an hr project.....could be the oil ring on the piston...warming up is smokes but once the cylinder gest hot u dnt see it burnin oil.......i think ur oil ring is goin bad.....a buddy of mines oil ring is goin out and its burnin alot of oil u can see it drip from the exhuast....but really no power loss....idk

[justin1022]

Originally posted by bigballz400
put the old cam back in and see if it still smokes.....only an hr project.....could be the oil ring on the piston...warming up is smokes but once the cylinder gest hot u dnt see it burnin oil.......i think ur oil ring is goin bad.....a buddy of mines oil ring is goin out and its burnin alot of oil u can see it drip from the exhuast....but really no power loss....idk

ya around the end cap there is some oil sprits but i never lost any power.

[UNBROKEN]

mine did the same thing and it needed rings and valve seals

[justin1022]

Originally posted by bigballz400
put the old cam back in and see if it still smokes.....only an hr project.....could be the oil ring on the piston...warming up is smokes but once the cylinder gest hot u dnt see it burnin oil.......i think ur oil ring is goin bad.....a buddy of mines oil ring is goin out and its burnin alot of oil u can see it drip from the exhuast....but really no power loss....idk

could it possibly be over fueling? i was thinking that today because i was rideing and it does it only when i start riding for the first time that day then it quites after you hit about 4th then its good and it will start again if you are trail riding going easy you no thats why i thought it might be over fueling because when it needs the extra fuel it quites smoking but then when im going easy it smokes i went to a sand pit and was rideing the piss out of it to see if it would smoke and it didnt not at all so i dont no what it is.. and my oil doesnt move on my dip stick its so weird.

[DementeD]

blue smoke = oil
black smoke = gas