blew a head gasket

[tyman2395]

hey guys i blew my head gasket while breaking in my motor it has a 11:1 wiseco piston why would it blow a gasket?

[shawn3389]

what are you running for jets? if it isn't jetted right could cause that...also did you get HD head studs or new ones??

[tyman2395]

i got the 450r carb and was running a 155 dyno jet and no same studs but i will go get a pic of it to show yas lol

[shawn3389]

a 155 sounds small to me i run bigger and i have a stock piston and mine runs very nice and the plug looks good too

[jcs003]

possibly had head bolt torque spec issues.

[dariusld]

It probably didn't seal well from the start. What kind of gasket did you use? How was the condition of the motor before the rebuild? Does it have alot of hours on it. How was the head and cylinder surfaces? I have a feeling this won't be the last head gasket you blow.

[dariusld]

Originally posted by tyman2395
i got the 450r carb and was running a 155 dyno jet

I didn't understand this part.

[shawn3389]

a 155 DJ is small, if you run a motor lean bad things will happen......

[tyman2395]

what is a good gasket kit brand i am gonna get one this week

[jcs003]

Originally posted by tyman2395
what is a good gasket kit brand i am gonna get one this week

cometic

[tyman2395]

so this kit ?

http://cgi.ebay.ca/COMETIC-TOP-END-GASKET-KIT-HONDA-99-06-TRX400EX-400EX_W0QQitemZ120387656034QQcmdZViewItemQQptZMoto rs_ATV_Parts_Accessories?hash=item120387656034&_trksid=p3286.m20.l1116

[jcs003]

Originally posted by tyman2395
so this kit ?

http://cgi.ebay.ca/COMETIC-TOP-END-GASKET-KIT-HONDA-99-06-TRX400EX-400EX_W0QQitemZ120387656034QQcmdZViewItemQQptZMoto rs_ATV_Parts_Accessories?hash=item120387656034&_trksid=p3286.m20.l1116

that is what i bought for my 89mm kit.

[tyman2395]

k and should i get heavy duty head studs?

[NacsMXer]

Originally posted by tyman2395
so this kit ?

http://cgi.ebay.ca/COMETIC-TOP-END-GASKET-KIT-HONDA-99-06-TRX400EX-400EX_W0QQitemZ120387656034QQcmdZViewItemQQptZMoto rs_ATV_Parts_Accessories?hash=item120387656034&_trksid=p3286.m20.l1116

That seems to be the right one if it's a "top end" gasket kit. Make sure to ask the seller exactly what you get because the ebay item description doesn't tell you much.

[jcs003]

yes mune are from GT thunder. have a machine shop tap the holes for you with the tap GT thunder suggests.

[tyman2395]

so a roll form tap ?

[jcs003]

Originally posted by tyman2395
so a roll form tap ?

thats what they recommend. they have a MSC part number on their website for our convience.

[brian76708]

did you torque the studs to spec?????

[Ruby Soho]

get a MLS headgasket.

[jcs003]

i looked up my records and my builder actually used the gasket from JE pistons. my builder must not of used my cometic. anyhow, cometics are good gaskets.

[tyman2395]

heres some pics

http://i492.photobucket.com/albums/rr286/tyman2395/my%20400ex/100_1392.jpg

http://i492.photobucket.com/albums/rr286/tyman2395/my%20400ex/100_1393.jpg

http://i492.photobucket.com/albums/rr286/tyman2395/my%20400ex/100_1394.jpg

http://i492.photobucket.com/albums/rr286/tyman2395/my%20400ex/100_1395.jpg

[dariusld]

Man, now thats a blown head gasket!!!

Did the head bolts feel tight when you took them off?

[n811]

I seem to have problems with aftermarket gaskets?I dont know why but they all eventually leak?? I spend a bit more for Honda gaskets now and No leaks?

[tyman2395]

dariusld Man, now thats a blown head gasket!!! Did the head bolts feel tight when you took them off?

yup they were pretty tight

[F-16Guy]

The forward stud is the one that usually pulls because it is closest to the exhaust ports. The aluminum gets hotter there, and eventually weakens, allowing that stud to pull out. My 416 did the same thing. I checked the studs and put a new gasket on. The nuts torqued down fine, but it blew again within an hour or so. I decided at that point to have GT Thunder to install HD studs, and I haven't had a problem since.

[tyman2395]

ya i am having my motor redone by the shop my mom is paying for it i ordered the crf450 cam chain and the gtthunder hd studs, i am getting them to look over my gears and their putting in a +4 crank and i already have my 416 piston so it will be a 440 now right? there putting in the studs and chain. Should i put a new clutch kit in it? they look good but i might get a new one i heard stock is the best one to run? and there putting in a aftermarket oil pump my friend has for me my mom is paying for all this and once i get it back i am taking out to our local shop and getting them to rejet it for me should be relaibe then lol :devil: