416ex problem!

[flattracker4389]

hey yall i rebuilt my 400ex a few months ago and got it bored to a 416ex with an 11:1 wiseco piston. i used a full set of cometic gaskets. after i put it back together it ran fine, but i noticed a little oil the front of the head. i wasnt sure if it was oil that came out the motor when i took it apart a few times to get it perfect. so i tourqued all the bolts to the right measurement so i have no clue what was the matter. i checked the oil everytime i rode it to make sure it had oil. after the break in, i participated in a parade. i could tell that the bike was getting hot and on the way back down the road after the parade my bike stalled and would not crank at all. the next day i noticed more oil at the bottom of the head at the base. do yall have any idea wat happened? im goin to check the spark plug but that doesnt explain the oil at the base. do u think i blew the base gasket? if so then are there any gaskets that are more heavy duty then cometic. they are made of paper so they might not have been strong enough for the compression. if u have had a ploblem like mine or could help me in any way i would appreciate it.

Sean

[flattracker4389]

do yall think i might have blown the head? im hoping this isnt too hard of a fix, watever the problem.

[mojoe2878]

where is the oil actually coming from? the bottom of the head or the bottom of the jug where it meets the case?
im confused, you say its coming from the bottom of the head and that the gasket there is made of a paper material, cosmetic head gaskets are not made of a paper material, they are flex steel gaskets, so i am just wondering if you mean its coming from the bottom of the jug where there is a paper gasket.
if its coming from the bottom of the jug, then you may have torn the paper gasket when you assembled it and didnt notice, those base gaskets are easy to tear. that gasket does not blow from high compression ratios.
if its coming from the bottom of the head, then your gasket isnt sealing good, you may have scratched the mating surface or it has slightly warped, or you could have a head stud that is pulling out.
i would go back with the cometic gaskets when you put it back together, your problem isnt from a chit gasket and i have used cometic gaskets on my 440 for a while now and have never had any issues do to gasket failure.

[flattracker4389]

the oil is coming from the bottom of the head where it meets the case. this is the first time i have rebuilt a motor and a friend said that cometic gaskets were paper gaskets. that is why i said paper gaskets. would the messed up gasket be the reason it doesnt run? i havent broke the back down yet so i do not kno if the head is blown. what should i look for to tell if its blown? where can i get heavy duty studs and how much do they cost?

[440exnacsracer]

the stock base gasket is paper also, there is nothing wrong with stock gaskets, they are actually really good. if you didnt harm the stock gaskets, i would put those back in place. cometics are great though. perhaps you didnt clean the surfaces to begin with and left a little oil residue? also, what do you mean by"oil that came out the motor when i took it apart a few times to get it "? did you drain the oil before you started? lmk, im trying to help.
Ben

[flattracker4389]

i'll take a look at my stock gaskets to see how they look. what i meant was that the last time i was putting it together the head cover looked a little off so i took it back off and checked to make sure it was on correctly. when i took the cover off, a small amount of oil from around the cam ran out over the front of the motor. nothing mechanically wrong jus a little mess i made. wat do i need to look for to tell if the motor is blown or not? i have only rebuilt a motor once.

[440exnacsracer]

if the base gasket has no signs of rupturing, i would go get some locktite gasket former (in a red bottle). run a ring around the top and bottom of the base gasket and the head gasket while your at it. this stuff works great and keeps any air from escaping the gaskets. preventing minor blow by usually prevents blown gaskets. if you have to buy new gaskets, use this stuff anyway, it should put a fix to it. good luck
Ben

[motoboy66]

Sounds like you seezed the engine after the parade. That would happen with a blown head gasket. If you took the bike apart a few times, you may have pulled the studs out a little bit. This happened to my buddy with his 400. Everything went together fine, but the engine would seeze soon after. If the studs are pulling out, they will let the head gasket leak, this will inturn allow oil to leak out, and the mixtur to lean out causing the engine to run hotter, causing it to seeze.

[flattracker4389]

i bought some new gaskets today. my friend hooked me up with a good deal. i have a new head and base gasket. by seezing do u mean that i will have to re-bore the motor ? what exactly do u mean? do u kno where to get heavy duty studs?

[motoboy66]

You said that it would not crank, like the piston was stuck, and would not move. This is a seeze. You may be ok as the piston will take most of the abuse, but chances are if this happened, you will need a new piston.