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Discussion Starter · #1 ·
On my 01 MXZ 700 i keep blowing base gaskets. I installed Cudneys 670 piston kit so i have to stack a .8 and a .5 base gasket. I have run this flawlessly for 3 years now. I reringed the engine over the summer. On the first 50 miles i blew a base gasket. It spit it out the mag side and it was allowing it to injest coolant. I was able to get replacement parts over the weekend while on vacation. I used HI-Tak to glue the 2 gaskets together then i torqued them to spec at 21 foot lbs. I put on an easy 30 trail miles and it was fine. Then we hit the lake and ran about 10 miles or so about 80 - 100 mph. Again i spit a gasket but this time out the PTO side. Any idea's why? I know many run this set-up w/out any issues.
 

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mudweiser said:
I used HI-Tak to glue the 2 gaskets together then i torqued them to spec at 21 foot lbs.
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I believe the jugs torque to 29 Ft. Lbs. and the head to 21 Ft. Lbs. The 600 HO uses the identical bottom end and that's what it is.
 

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mudweiser said:
So you thinki the differance in 8 lbs is whats causing the base gaskets to blow out?
What sealant is everyone using when they glue these together?
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8 lbs is alot. I think that's the problem alright.
 

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Why don't you just get a thicker gasket instead of gluing two together?
In fact, why not call cometic and get a 60 thou gasket for $20 and take your head to the machine shop and pay one of the machinists $15-20 cash after hours to cut your head on the mill if you can't do it yourself so you can run your pump gas. Instant shim kit and you only paid at most $50 Canadian, you have'nt had to stack gaskets like you should'nt anyhow, and run better. It's worked on my motors for the last three years, so I know it works fine.
 

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Discussion Starter · #8 ·
milrlite said:
Why don't you just get a thicker gasket instead of gluing two together?
In fact, why not call cometic and get a 60 thou gasket for $20 and take your head to the machine shop and pay one of the machinists $15-20 cash after hours to cut your head on the mill if you can't do it yourself so you can run your pump gas. Instant shim kit and you only paid at most $50 Canadian, you have'nt had to stack gaskets like you should'nt anyhow, and run better. It's worked on my motors for the last three years, so I know it works fine.

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I need 51 thousand of height. Much more then that and i have way too much port timing (the cylinders have been ported) and the thing falls flat on it's face and EGT's go way down. I need to stack the gaskets because of the taller deck height of the 670 pistons. Thanks for the advice though. I spoke with the dealers Tech and he said when they do this, they use a small punch and peen the cyliinder and case to help hold the gasket in. from there use Permatex spray hi-tak to hold it in. I guess i will try that and see how it goes with the cylinders torqued to spec.
 

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mud, should be able to stack them dry but if it's giving you trouble try a very light coat of hylomar blue on them. It doesn't harden like the hi-tak and allow things to shift around and settle in place.

Not to question your skills but make sure you square up the jugs with the y pipe, and jug spacing BEFORE you tighten the base bolts. If your using the inset style head use that to set your jug spacing. If your using the alum shim it may help to rough it up a little. IMO the 700 case jugs is not a problem for gaskets that would require punching the surface, at least not comapared to some other motors. If you choose to do it , one of the those auto snap center punches at the lightest setting works pretty well.

The confusion about torque spec l is partly doo's fault. The early 700's used 8mm bolts and were spec'd at 21, doo was slow to change the spec when they recast the motor and used 10mm.
 

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Discussion Starter · #10 ·
BMEP said:
mud, should be able to stack them dry but if it's giving you trouble try a very light coat of hylomar blue on them. It doesn't harden like the hi-tak and allow things to shift around and settle in place.

Not to question your skills but make sure you square up the jugs with the y pipe, and jug spacing BEFORE you tighten the base bolts. If your using the inset style head use that to set your jug spacing. If your using the alum shim it may help to rough it up a little. IMO the 700 case jugs is not a problem for gaskets that would require punching the surface, at least not comapared to some other motors. If you choose to do it , one of the those auto snap center punches at the lightest setting works pretty well.

The confusion about torque spec l is partly doo's fault. The early 700's used 8mm bolts and were spec'd at 21, doo was slow to change the spec when they recast the motor and used 10mm.
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The cylinders were squared with the pipe first. As far as the aluminum shim, i'm only running 2 base gaskets. No shim.
 
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