- Location
- Forsyth County, GA
This is what I got on my freshly rebuilt engine...this seems high for 35cc domes on my ADA and maniac ported 735?? maybe because the cylinders are coated with oil and it's so fresh...? (Cheap tester too)
Does this seem right (compression)
- Thread starter paczowski123
- Start date
High Speed Industries
Your one stop shop for quality parts @highspeedind
- Location
- Lake Havasu City, AZ
I think the oil in the cylinders is throwing your gauge off. Start the ski and get the oil cleared out. Let the engine cool completely and try the test again.
- Location
- Forsyth County, GA
Yeah, I kinda figured something like that...it kinda caught me off guard when it kept going though!! Ha...I was thinkin no more than 190-195 and I got this..I'm gonna do the break in and retest with a different gauge
High Speed Industries
Your one stop shop for quality parts @highspeedind
- Location
- Lake Havasu City, AZ
Oil or fuel in the motor will make a huge difference. It can also ruin your gauge.
- Location
- Forsyth County, GA
Yeah, I knew that...I turned it over many times with the plugs out to disperse any standing oil or what not...but, it's a cheap gauge and wanted an idea...that just seemed high
- Location
- Forsyth County, GA
Yeah, I'm going to run it and do a break in run to get a better baseline...probably use a different gauge as well..I figure it's probably a combo of being so fresh and unseated, as well as oil on the cylinder walls..
- Location
- Forsyth County, GA
Ha! The gauge very well could be "poop!" We'll see what numbers we get with a second gauge!
- Location
- the jetski grave yard
on a 4 stroke that has low compression, thats how you tell if its a ring or valve problem. squirt oil in the spark plug hole and check compression. if it goes up its rings, if not its valves. it doesnt take a lot of oil to make a 2 stroke read very high comp , but unless you put oil in the cyl, oil isnt the cause of it being high.
- Location
- Forsyth County, GA
Well, there was oil in the cylinders from the rebuild...and it has not been run since the build...that plus the cheap gauge is I think giving me the false reading...a pic below is during the rebuild to show the oil I coated everything in...but like I said it was turned over many many times with the plugs out to help disperse the oil...but who knows since it was not run
- Location
- the jetski grave yard
if you crank it over a bit with the plugs in, all the oil will go by the rings and you can get an accurate reading. oil doesnt just stay there and keep you reading high. in the pic, it looks like oil is running down the walls? that'll raise comp for sure.
- Location
- Forsyth County, GA
I'll try that, thanks!...and next time I'll use a gauge that hasn't been abused so much...
- Location
- St Charles IL
35cc domes on my 781 is pushing around 210+
- Location
- Victoria BC
The 760 ADA 35cc domes give a higher compression than the 701 ADA 35cc domes.
Big Kahuna
Administrator
- Location
- Tuscaloosa, AL
35cc domes on my motor @83mm was blowing around 190lbs
Philip Clemmons
Owner, P&P Performance
- Location
- Richmond, Va
Those numbers are not unreasonable.
- Location
- Forsyth County, GA
But if they held at that psi even after break in, I would need to be running at least a 50/50 mix of race fuel and pump gas??
Big Kahuna
Administrator
- Location
- Tuscaloosa, AL
Depends on riding style. WOT the you need more octane. If riding a short hull where your just riding around in circles and depending on your setup you may be ok. But not sure accuracy of your gauge. And that is all a gauge is. Just one reading of part of your setup.