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-   General Q & A (https://www.offshoreonly.com/forums/general-q-20/)
-   -   496 ho with raylar 525 keeps blowing head gaskets (https://www.offshoreonly.com/forums/general-q/361687-496-ho-raylar-525-keeps-blowing-head-gaskets.html)

Krope002 07-09-2019 04:08 PM
And I found out from the dealer today it was GM head gaskets. I'll look into that filter. How'd you end up finding out that was the issue?

SB 07-09-2019 04:28 PM
Originally Posted by [email protected] (Post 4695770)
My 496 was blowing head gaskets and pistons, It turned out to be a missed placed 10 micron fuel filter, (causing the fuel to boil and cavitate,) The filter was on the intake side of the fuel pump, we reinstalled it on the outtake side, so far it running well.
Good luck
Was your 496 a Gen VII GM 496 ? or a 4.25" stroked 454 to give you the 496 ? I'll guess the later. :)

Keith Atlanta 07-09-2019 06:51 PM
Originally Posted by SB (Post 4695843)
Was your 496 a Gen VII GM 496 ? or a 4.25" stroked 454 to give you the 496 ? I'll guess the later. :)
SB, if its Raylar, its 8.1/496 Gen VII

Keith Atlanta 07-09-2019 06:54 PM
Krope, the issues may be related. But maybe they arent. Are the bolts holding the heads down SRP or original TTY? (Torque To Yield) TTY shouldnt be reused. There is a chance the TTY bolts are spent if reused and will stretch. Mostly everyone knows this but maybe somebody didnt.

Krope002 07-10-2019 07:36 AM
They are ARP head studs now

SB 07-10-2019 07:47 AM
Originally Posted by Keith Atlanta (Post 4695863)
SB, if its Raylar, its 8.1/496 Gen VII
He did not mention, thus the question.

BUP 07-15-2019 10:18 PM
Originally Posted by [email protected] (Post 4695770)
My 496 was blowing head gaskets and pistons, It turned out to be a missed placed 10 micron fuel filter, (causing the fuel to boil and cavitate,) The filter was on the intake side of the fuel pump, we reinstalled it on the outtake side, so far it running well.
Good luck
Your app is not stock per what you have posted and what fuel system do you have ? I know the 496 in my sleep and the 10 micron filter is a round disc pad filter in the bottom of the gen 3 cool fuel STOCK app and if one has the GEN 2 cool fuel the spin on water fuel seperating filters can be whatever micron rating. There is a 113 micron rated metal fuel canister fuel filter before the boost fuel pump on the gen 2 cool fuels / 496 s.

[email protected] 07-16-2019 11:27 AM
I’m new to the fountain boats, I didn’t even know fountains didn’t come with a speed and marine intake😱
Looking like I have a gen 2 system with a airmotive fuel pump\filter. Did these boats come with that oris that something that was added ?
I wish there would have been a 113 micro filter in front of the pump, and I wish I had caught the 10 micron that was In there. Before I cooked the motor.(2piston and both head gaskets, the boat ran strong 68 mph but now it runs stronger at 73. Mph


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