ninjette.org - View Single Post - Low Compression On A Cyclinder, Should I Replace Piston Rings?

nocturncal · February 6th, 2020, 06:39 PM

Did a compression test on my bike.

Bike runs. It sounds like my cylinder may be misfiring but I'm not sure. Sending my carbs to be cleaned today.

Compression test after bike warmed up:

Cylinder #1 (Left side when sitting on bike)
Dry: 145 psi
Wet: 205 psi

Cylinder #2:
Dry: 110 psi
Wet: 195 psi

Valves just adjusted and are in spec.

I don't have a leak down tester, I may consider buying one, but not sure if a leak down test could tell me much more than the compression test.

Wondering if there is anything else I should check. If I do end up needing to replace piston rings, how many days should I reserve if I worked all day on getting the rings on? I've never torn down an engine, closest thing is doing valve adjustments myself.

Does this look like a probable piston rings replacement scenario?
I've heard of those products like Rislone Compression Repair additives, but do they actually work? Could this be a temporary solution (help for 10,000 mi)
Can I replace piston rings with the engine still on the bike?

February 6th, 2020, 06:39 PM	#1
nocturncal ninjette.org member Name: Cal Location: San Francisco Join Date: Jun 2017 Motorcycle(s): '09 Ninja 250R Posts: 180	Low Compression On A Cyclinder, Should I Replace Piston Rings? Did a compression test on my bike. Bike runs. It sounds like my cylinder may be misfiring but I'm not sure. Sending my carbs to be cleaned today. Compression test after bike warmed up: Cylinder #1 (Left side when sitting on bike) Dry: 145 psi Wet: 205 psi Cylinder #2: Dry: 110 psi Wet: 195 psi Valves just adjusted and are in spec. I don't have a leak down tester, I may consider buying one, but not sure if a leak down test could tell me much more than the compression test. Wondering if there is anything else I should check. If I do end up needing to replace piston rings, how many days should I reserve if I worked all day on getting the rings on? I've never torn down an engine, closest thing is doing valve adjustments myself. Does this look like a probable piston rings replacement scenario? I've heard of those products like Rislone Compression Repair additives, but do they actually work? Could this be a temporary solution (help for 10,000 mi) Can I replace piston rings with the engine still on the bike? Last futzed with by nocturncal; February 7th, 2020 at 01:16 AM.