leaking head gasket

[Deleted]

gday, has anybody ever built a motor and it starts straight up with no leaks at all, spent 30 minutes tonight trying to finally start it, leaking carby sorted but head gasket is leaking, didn't even look like starting , will check for spark, recheck timing,put air mixture screws out 1 1/2 turns and will try some sealant on the gasket, fingers crossed it might at least turn over a bit.in the Haynes it said from memory that 17 lb,s is the right torque for head , is that right?, seems a bit gentle to me, thanks

[skaterboy]

Top of the morning to you
I have recently rebuilt a motor and the figure of 17IBS FT is close seem to remember somthing like 17.2 ib ft. Did you use a pattern or genuine head gasket. I have tried both and as a result always try and use a genuine one covered in silcone in a bid to help it bind. Have you looked at the head to see if there a small lip between the face of the head and the dome of the head. I only mention as i have a similiar problem ended up having to change the head.

[rich]

I know the manuals say not to use sealant but I always use a very thin smear of RTV and not had any leaks even using pattern gaskets. It's also very important to retorque the head once the engine has been thoroughly warmed up and allowed to completely cool down again.

[peterlc2]

i had mine rebuilt and started 1st kick amazing, then i holed a piston rebuilt top end and again it started 1 st kick, always use genuine headgasket and tighten as you should all the best Peter

[Fingermaus]

Jun 17, 2012 15:50:04 GMT 1 rich said:

I know the manuals say not to use sealant but I always use a very thin smear of RTV and not had any leaks even using pattern gaskets. It's also very important to retorque the head once the engine has been thoroughly warmed up and allowed to completely cool down again.

I've done exactly this with a pattern gasket and all's well so far

[rdstars]

I do the same as Rich there, not had a leak once with a patten gasket and I've had my top end off a number of times. This time around I am using one layer of the patten gasket, RTV and job done.

One little hint, after doing the head gasket leave it till the next day or so till you fill it and start, gives the silicone time to go off.

[Deleted]

thanks for all the replies, it is a genuine gasket so, i will have a go with some sealant and give it a day to go off a bit and take it from there,the head does look to have all its squish area still there,, cheers ken

[ngordoncrosby]

I thought it was a little light on the torque as well so I think I went up to about 20, and had know probs, but also used some sealant but I wished would have used a genuine gasket now

[arrow]

I never use any extra sealant on the original Yamaha gasket. The original gasket is coated with something that makes it stick like 'sh*t to a blanket' on the alluminium surfaces. This is indicated by the fact that it is extreamly hard to seperate the joint. The only time I had problems with the gasket itself was when I used a sealant and it stopped this strong addesion process from working correctly. I have used a radiator leak compound but this was for a different issue (crack between stud hole and barrel) With complete success.

[Deleted]

well checked it out this morning, pulled head and made a discovery, the bike had been crashed(knew That) and the left hand barrell had been welded where one of the exhaust studs had busted, when i bolted on the pipe it pulled the left barrell forward raising it about a millimetre at the back were the reed block is, hopefully it hasnt pulled the head out of shape,i will mount the original pipe that came with it as the bit at the front where the bolts go through look bent on one side, will see if it was done to seal properly without pulling head out of alighnment, hopefully will be a satisfactory outcome, poor old gasket never stood a chance to seal properly, thanks

[webbo]

Ken, I fitted a pattern gasket, leaked, so used a smear of instant gasket. Still leaked but then I had to spend ages cleaning up the head and barrels covered in instant gasket, I then bought a gen Yam one and sealed first time. I still rechecked the torque after a heat cycle. Cheers Webbo

[Deleted]

gday webbo, i did indeed use a gen gasket,but no gasket would have worked i believe due to the barrell getting all pear shape after tightning up the exhaust on the left hand side, hopefully it all sorted now, i will let you know in a day or so, having said that the bike looks good, i might just mount it on the wall like a lions head and look at it, lol

[47x]

Jun 18, 2012 0:37:33 GMT 1 arrow said:

I never use any extra sealant on the original Yamaha gasket. The original gasket is coated with something that makes it stick like 'sh*t to a blanket' on the alluminium surfaces. This is indicated by the fact that it is extreamly hard to seperate the joint. The only time I had problems with the gasket itself was when I used a sealant and it stopped this strong addesion process from working correctly. I have used a radiator leak compound but this was for a different issue (crack between stud hole and barrel) With complete success.

i never use sealant on gaskets,as arrow sez,the original gasket has sticky shit to make it seal.