If the compression was good before putting the head on would the problem not be in the head rather than the cylinder? And if so wouldnt it be easier to return the head than modify the cylinder?
compression and exaust temp sensor sxr
- Thread starter flipsxr800
- Start date
If the compression was good before putting the head on would the problem not be in the head rather than the cylinder? And if so wouldnt it be easier to return the head than modify the cylinder?
If the base gasket is a different thickness it will effect compression.
You have alot you didn't check. Is the ADA head & domes brand new?
Are they for a 750 or 800sxr?
I'd pull the motor back down and check base gasket. Should be .020
I was not there for re-assembly so I can only give the info that I know.
ADA head is brand new and was ordered for an SXR, weather or not an 800 was shipped I dont and from what I can tell they would be visually the same as the 750 but I would assume that a 750 head on an 800 would still provide more than 125-130 psi. How much can the base gasket effect the compression? 50psi?
Who is bulding your motor?
It's good to know that the ADA head & domes are new. Much less chance of being wrong.
Is your motor still on stock bore?
Yes, I thicker base gasket will give less compression because there is more space left between domes & piston. Measure squish or base gasket
It is not my motor, I am trying to help my buddy out who is putting his ski together. He doesnt have a lot of time to get online so I am doing the research for him. Stock bore, barely over one MN season on the ski. We will measure squish next and try to find a nice compression guage. Thanks.
SXR-FOREVER
Finally Flippin
- Location
- Lake Minnetonka, MN
Kawi service manual says to hold throttle wide open and crank the motor until the compression guage stops rising.
So since Jon is running 150, the 27-28-29cc domes should bring him up to 180
So since Jon is running 150, the 27-28-29cc domes should bring him up to 180
- Location
- minnesota
thanks trevor for looking that up
I know I would just hate to solve a low compression problem by swapping smaller domes in when there is a slight chance the problem is not from the domes at all. Those 32cc domes "should" be at 180 according to ADA but I am going to give them a call today. But if we go by the crank till it stops method he is at 150 on a cold motor and a cheap guage so maybe it is not that far off at all.