avasdaddy
New member
i have 128 lbs of compression in all three but i know specs are around 140-150 lbs. Can anyone tell me if this is too low or how low is too low?
hereismylife
Active member
I was told that 130 or lower the engine should be refreshed or rebuilt....
Just make sure they are within 10% of each other...
Just make sure they are within 10% of each other...
avasdaddy
New member
they are all within %10 but how much is it to refresh trhe engine ands what exactly does that take?
If I were you I would do new rings, pistons, etc. Weisco (SP?) sellls a kit to do a new top end. About 400 bucks...
i have 135 with a peak head and a peeled gasket
it was 112 new
it was 112 new
Bluemonster2
New member
I dont know what these motors come with stock for compression but I know that they dont have 150psi with all layers of your headgasket. My 98 xtc is around 135psi w only 5000 km full headgasket. My stepdads sxr 600 was in the 125 range from about 6500km until he rebuilt it with 13000(was still running very good) Most people w redhead motors have between 120-130psi. The important thing is that all the cyl are close to each other.
Also when you do eventually rebuild it use oem yamaha pistons and rings wiseco are junk especially for a stock sled, to much clearance when cold and they have to be religiously warmed up and broken in. The sxr 600 that my stepdad rebuilt has 145-150 w only 1 layer of headgasket,
Also when you do eventually rebuild it use oem yamaha pistons and rings wiseco are junk especially for a stock sled, to much clearance when cold and they have to be religiously warmed up and broken in. The sxr 600 that my stepdad rebuilt has 145-150 w only 1 layer of headgasket,
Snowsnake
New member
Personally if they are with-in 10% I'd ride it the way it is or at least try a different tester.A compression test on a 2-stroke isn't really very definitive of the condition anyway.How many miles on it?If it's reasonably low and you really feel the need I would just re-ring the stock pistons as they are a far better piston than a Weisco.IMHO people get carried away "freshening up these engines".I've got approx.15,000 miles on my Viper and the motor hasn't been apart.If I would've built it every 5 K likesome do I could have spent upwards of a grand and for what?It still gets to a 100 mph pretty quick withmore left.IMHO keep your money and use it for fuel.
bluemonster1
LIFE MEMBER ONLY ONCE!!!
GOOD MORNING Scott.....
Bluemonster2
New member
bluemonster1 said:
Good morning Doug, lol Actually not feeling too bad today a little weak but not as sick as I thought I was gonna be!!!
mopar1rules
Active member
i wouldn't worry about rebuilding it. if it runs good and all cylinders are within 7% from one another, then just run it. also, not all gauges read the same, so don't get too caught up in compression numbers from the gauge. most important is that all cylinders are within 7% of one another.
methanolhemi
New member
Compression does not tell you if your rings
are worn out anyway. A leak down test will
give that answer to you. There is a write up
in tech pages from Mrviper.
are worn out anyway. A leak down test will
give that answer to you. There is a write up
in tech pages from Mrviper.
Weatherbyman
Member
compression
So much depends on the conditions under which you test and the compression gauge itself. If you have 128 PSI on all three cylinders, I would ride it and enjoy the scenery.
So much depends on the conditions under which you test and the compression gauge itself. If you have 128 PSI on all three cylinders, I would ride it and enjoy the scenery.