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 Post subject: Head gasket gone??
PostPosted: Thu Feb 08, 2018 8:43 pm 
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Joined: Mon Feb 25, 2008 11:44 am
Posts: 345
Location: Northern Ireland
Is my head gasket leaking? Rebuilt my engine about 7 years ago. Just started it this week for the first time since rebuilding it. I have started it 3 times now, just to heat cycle it (new cranks and pistons/rings) Bubbles coming from the radiator, at first I thought it was just air bleeding out but now I think its because the coolant system is getting pressurised. Also, creamy brown oil gathering at tailpipes which reminds me of the emulsified oil you see in a four stroke rocker cover when a head gasket is gone. Check out this video and let me know what you think;




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 Post subject: Re: Head gasket gone??
PostPosted: Thu Feb 08, 2018 9:41 pm 
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Joined: Sat Feb 04, 2012 7:36 am
Posts: 2438
Location: Eastern Ontario Canada
Yes :sad:

Did you use Yamaha head gaskets? It is highly unusual for them to leak.

Did you re-torque the head bolts?

Aftermarket head gaskets have a very high failure rate and most here will tell you not to use them.

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1985 RZ500
1985 RZ500 Project Bike
1986 RG500 ATR
1986 NS400R
1987 TZR250
1988 Honda RC31
2007 DL650 VStrom
2014 Triumph Thruxton Modified


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 Post subject: Re: Head gasket gone??
PostPosted: Fri Feb 09, 2018 8:19 pm 
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Joined: Mon Feb 25, 2008 11:44 am
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Location: Northern Ireland
Thanks John. Its so long ago I cant remember if they were genuine gaskets or not! Probably not. I'll have to try and get some yamaha ones.

I had re-torqued them ok.

Any tips to get them sealed; any dressings etc that can be sprayed on them or such?


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 Post subject: Re: Head gasket gone??
PostPosted: Fri Feb 09, 2018 11:07 pm 
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Joined: Sat Feb 04, 2012 7:36 am
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Location: Eastern Ontario Canada
There is no need for sealant with Yamaha head gaskets. keep it as simple as possible and it will work just fine.

You do need to check your heads to make sure they are actually flat. If the head is warped you will never get a proper seal. Heads can warp by not following the proper bolt number sequence, poor milling, etc.

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1985 RZ500
1985 RZ500 Project Bike
1986 RG500 ATR
1986 NS400R
1987 TZR250
1988 Honda RC31
2007 DL650 VStrom
2014 Triumph Thruxton Modified


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