2004 Mule 550, compression loss overnight!!

[Joey S.]

Update. Got the engine out, & removed the piston. Cylinder walls look fairly decent; no scoring I can see or feel. The 2nd ring on the old piston snapped in half as I was taking it off the piston, & they were very worn. I think that's the issue. I'll finish putting it back together tomorrow, then perform the leak down while it's on the bench. With any luck, this will fix it so it'll last another year or two. Next time, I'll just get a remanufactured engine; there's a place here in St. Louis that sells the complete engine for $950.

Joey

[Travis]

On 11/8/2023 at 9:03 AM, Joey S. said:

I have a 1999 Mule 550 which only had 25 psi on compression test. Leak down test indicated cylinder or rings issue, as I could clearly hear the air leaking when I removed the dip stick. Nothing out of the exhaust, & maybe a little out of the intake. I've removed the head, & there's a lot of carbon build up on the valves. I've ordered new valves, & am engine rebuilt kit, complete with piston & rings. When you pulled your piston, did you remove the engine, or were you able to remove the piston while the engine was in the frame? Thanks! I made the mistake of buying this sight unseen while I was deployed, & didn't think about asking for a compression test prior to paying.

download my manual i uploaded here, will tell you everything you need to know and then some