SXR Compression Vs. Motor Life

[icecoled007]

I just picked up an 05 SXR and the guy just put on a milled stock head.

I am planning on keeping this ski stock. Dont really want to be spending a bunch of money on it.

The ski is putting out about 175 in each cylinder. How much will this shorten the life on my motor? Should I just put a stock head on?

Also he put O-rings on the stock head. Has anyone heard of people doing this before?

 

[Mark44]

175 is not a lot of compression but of course any more psi on the piston works the engine harder but at 175 I wouldn't worry about it. O rings are used all the time. I use an ADA O-ring head on my skis.

Mark44

 

[djkorn1]

175 isn't too high...It'll be fine. Just leave it. Some stock SXRs are at 175.

 

[kevbo]

Dont understand why he would install an O-ring in a stock head unless it has replaceable domes or an other than OEM gasket was to be used. Use a new OEM gasket if possible even with the O-rings.

 

[suva]

I'd guess he had a groove machined in the head to hold the compression orings and has sealant to seal up the water passages.

 

[tor*p*do]

also if you go to a stcok gasket it will add volume the thickness of the gasket
and lower the compression

 

[Scorn800]

Thats fine to run. It's similar to a r&d head which uses o rings around domes only. Just use a skim coat of 1211 when reinstalling.
This boat is in CO and read 175? compression will be more at sea level.

 

[Idok]

something doesnt sound 100% right........even and especially if the head was machined for an O-ring it would bump the compression WAY up.....or at least it does on a yami..

 

[Lucaumpits]

what about 235psi?:naughty:

175 is not a lot of compression but of course any more psi on the piston works the engine harder but at 175 I wouldn't worry about it. O rings are used all the time. I use an ADA O-ring head on my skis.

Mark44

 

[icecoled007]

something doesnt sound 100% right........even and especially if the head was machined for an O-ring it would bump the compression WAY up.....or at least it does on a yami..

Ya, thats what I initially thought also.... the compression is lower at higher altitude. If this ski goes to sea level it will read over 175.

 

[icecoled007]

I'd guess he had a groove machined in the head to hold the compression orings and has sealant to seal up the water passages.

Ya, thats what he told me. The only problem is I am missing the little hole in the OEM gasket that direct water. Will this be an issue?

 

[djkorn1]

yes, it will get no water and overheat.

 

[icecoled007]

yes, it will get no water and overheat.

I dont think it wont get any water.... it wont get directed water. Right now it has the full wide open areas for water to flow through. THe OEM gasket restricts the water with the little holes