- Location
- atlanta
New built never ran 61x/62t. Bored to 82, thrust girdle head with 35 domes. Compression 215/220... Any thoughts? Intake and exhaust where not on the block when I spun it over
High compression after head install
- Thread starter yamahaulass
- Start date
bored&stroked
Urban redneck
- Location
- AZ
I think it'll run great lol
Otherwise you sure the domes are actually 35cc?
Otherwise you sure the domes are actually 35cc?
- Location
- atlanta
Yea double checked the domes.. Ya2135L
joecef
Live fast, Die Fat
- Location
- Canada, EH
My ski is the exact same, same head same domes. I'm at 215 in both. I checked with two different compression testers. I'm thinking run with it haha. That's what I'm gonna attempt. Or if your worried go up in domes. Try 37cc
Quinc
Buy a Superjet
- Location
- California
Pull out the plugs and hold down the start button for 30 seconds to blow the oil out, then run her for another 30 seconds or so and check it again.
- Location
- atlanta
I pulled it apart and checked base gasket thickness.. Its a .5 gasket. Put it all back together, spun it without the plugs to get excess fogging lube out. Checked compression again and it is now at 225/230. Seems stupid high
Quinc
Buy a Superjet
- Location
- California
Cylinder or cases decked at some point?
- Location
- atlanta
I'm not sure but the cylinder is 119.2 tall so I'm thinkin that's not it. And joecef is having the same issue with the same set up. I would probably need 39cc to get to 185psi
Quinc
Buy a Superjet
- Location
- California
I would let it idle for a few seconds to make sure all the oil and crap in the cylinder is burned off.
- Location
- atlanta
Did not but l did spin the motor by hand with the head off and the piston stop just short of the top of the cylinder
- Location
- atlanta
Will do next time. If it's too tight what can be done?
I'd check it now, not before you ride it. Thicker base gasket.
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Big Kahuna
Administrator
- Location
- Tuscaloosa, AL
Bad answer. You may be raising port timing by doing that. Install OEM base gasket. Put the head on and check squish. If squish is to tight then you need to see about getting the domes cut and also measured to confirm CC volume.
- Location
- atlanta
I've got a decent amount of work before it's running, for like to get it resolved while the motor is still on the bench. I do trust the gauge but will try another. Maybe because the intake is not on? Also I though .6 was the thickest gasket available?
Big Kahuna
Administrator
- Location
- Tuscaloosa, AL
Also check with a different guage. After assembly 9f my motor last spring 8 checked compression and was blown away. I was blowing 220 lbs. Guess what. My 10 year old Snap On guage is way out of sync.