550sx XCompression is good

So with talking to some motor heads online I found that 140-150psi +/- 10psi difference in each hole is a suitable compression. In fact we are about 5 psi higher than the normal/average 550 for that year which I guess makes sense considering it is bored 1mm over. The only way we could get higher compression is by milling the head and/or porting and polishing the exhaust but that is done by people that know what they are doing and not a bunch of armatures in a garage toying with jet skis.

That's good news!

What kind of compression were you getting in your 550? With a Dremel you can probably port/polish a bit without screwing anything up, as long as you clean up the debris and don't take off too much material.

Brapple ... can't believe I just noticed that!

Jeremy wrote:

What kind of compression were you getting in your 550? With a Dremel you can probably port/polish a bit without screwing anything up, as long as you clean up the debris and don't take off too much material.

Brapple ... can't believe I just noticed that!

Brapple huh huh, umm the question is what kind of compression were we getting. The reading we got out of the 550sx 94' is at around ~142 hole one and around ~150 hole two. That was the first reading we took, well actually like an moron I took a reading without gaskets or the head tighten to spec but we won't go into that. The other 550 motor we have which is basically the same has 150 compression in each hole on the numbers. I guess if we wanted we could try to hone the cylinder and P+P the exhaust.

Weekend of April 30th I think we'll be there for kiddo's birthday and we could paint skis too!

Jeremy wrote:

Weekend of April 30th I think we'll be there for kiddo's birthday and we could paint skis too!

Bad ass!!!

She lives and skis, Got the 550SX put back together aside from some small things didn't get the gas tank back in b/c I can just pour gas down the carb to start etc. Started the replacement of fuel/exhaust lines pretty much done with exhaust about 6/10th done with fuel. Just need to pull the carb check for bad lines, crap in the carb see if it needs a rebuild. Other than that it is ready to go!!! Very exciting. It is load as shit with or without the exhaust so we will see how load the PJS and other 550 reed motor are. There were two bolts not tighten fully on the head at the front cylinder I am guessing this was the reason for poor compression in the front one and I am happy to report 150psi in the rear and 149psi in the front. I am pretty sure +/- 1 psi is in the area of awesome!!! Now both 550 motors are registering the same PSI ratio give or take. Getting pump for summer.

Thumbs the fuck up! I wish I can have that kind of success with removing the bearings from the DRZ linkage!