piston rings

It means It's your piston rings, if the compression didn't shoot up significantly, or not at all, it would've been the valves
Pete

pete greek1 wrote: It means It's your piston rings, if the compression didn't shoot up significantly, or not at all, it would've been the valves
Pete

So my rings are already bad at 28,000 miles?

blink543 wrote:

pete greek1 wrote: It means It's your piston rings, if the compression didn't shoot up significantly, or not at all, it would've been the valves
Pete

So my rings are already bad at 28,000 miles?

Could be. Maybe you or the PO used crappy filter pods? Aftermarket foam air filter? Overheated it? Ran it low on oil? Never changed the oil? Ran it hard before warming it up? The list goes on and on. It depends.

More likely, the rings are just a bit stuck from rich running and/or the bike having sat a lot.

Even if the rings are just stuck, replacing them will fix the problem (leading you perhaps to believe that they were actually worn).

All of that being said, 135PSI is perfectly fine compression. I wouldn't worry about it if I were you.

jackleberry wrote:

blink543 wrote:

pete greek1 wrote: It means It's your piston rings, if the compression didn't shoot up significantly, or not at all, it would've been the valves
Pete

So my rings are already bad at 28,000 miles?

Could be. Maybe you or the PO used crappy filter pods? Aftermarket foam air filter? Overheated it? Ran it low on oil? Never changed the oil? Ran it hard before warming it up? The list goes on and on. It depends.

More likely, the rings are just a bit stuck from rich running and/or the bike having sat a lot.

Even if the rings are just stuck, replacing them will fix the problem (leading you perhaps to believe that they were actually worn).

All of that being said, 135PSI is perfectly fine compression. I wouldn't worry about it if I were you.

Someone was telling me about some top end cleaner that u pour in the cylinders and let it soak and it cleans it out?

blink543 wrote:

jackleberry wrote:

blink543 wrote:

pete greek1 wrote: It means It's your piston rings, if the compression didn't shoot up significantly, or not at all, it would've been the valves
Pete

So my rings are already bad at 28,000 miles?

Could be. Maybe you or the PO used crappy filter pods? Aftermarket foam air filter? Overheated it? Ran it low on oil? Never changed the oil? Ran it hard before warming it up? The list goes on and on. It depends.

More likely, the rings are just a bit stuck from rich running and/or the bike having sat a lot.

Even if the rings are just stuck, replacing them will fix the problem (leading you perhaps to believe that they were actually worn).

All of that being said, 135PSI is perfectly fine compression. I wouldn't worry about it if I were you.

Someone was telling me about some top end cleaner that u pour in the cylinders and let it soak and it cleans it out?

Yeah, there's lots of stuff you can try, however, I'll point out two things:

1) Nothing I've ever put into the cylinders of an engine has done a damn thing to remove carbon (and I've tried it all [except the really caustic stuff])
2) If you were able to pour something into the cylinders to remove carbon, then that would actually lower your compression because all that carbon is actually making the combustion chamber a little smaller.

Knocking the rings loose is one thing--cleaning the combustion chamber is another.

People soak cylinders in ATF, Seafoam, acetone, etc in an attempt to free rings. It takes a *long* time soaking (and you have to replenish the fluid which either evaporates or drains into the crankcase).

I've had much better luck adding seafoam or MMO to the crankcase and just riding. Could take months or years to work, depending on how many miles you do, but you may indeed discover that compression goes up and oil consumption goes down. I'm sure everyone will tell you that seafoam in the crankcase will ruin your clutch etc. Well, it won't.

You don't seem to have a severe enough problem to warrant any action though. Unless it's burning a lot of oil, smoking, hard to start, etc. then that 135PSI is just dandy. If you ride hard and often and change your oil when you should, you might just find those compression numbers go up without any other action.

You really should torque that cylinder head down properly, though. That alone might get you up to 150PSI.

jackleberry wrote:

blink543 wrote:

jackleberry wrote:

blink543 wrote:

pete greek1 wrote: It means It's your piston rings, if the compression didn't shoot up significantly, or not at all, it would've been the valves
Pete

So my rings are already bad at 28,000 miles?

Could be. Maybe you or the PO used crappy filter pods? Aftermarket foam air filter? Overheated it? Ran it low on oil? Never changed the oil? Ran it hard before warming it up? The list goes on and on. It depends.

More likely, the rings are just a bit stuck from rich running and/or the bike having sat a lot.

Even if the rings are just stuck, replacing them will fix the problem (leading you perhaps to believe that they were actually worn).

All of that being said, 135PSI is perfectly fine compression. I wouldn't worry about it if I were you.

Someone was telling me about some top end cleaner that u pour in the cylinders and let it soak and it cleans it out?

Yeah, there's lots of stuff you can try, however, I'll point out two things:

1) Nothing I've ever put into the cylinders of an engine has done a damn thing to remove carbon (and I've tried it all [except the really caustic stuff])
2) If you were able to pour something into the cylinders to remove carbon, then that would actually lower your compression because all that carbon is actually making the combustion chamber a little smaller.

Knocking the rings loose is one thing--cleaning the combustion chamber is another.

People soak cylinders in ATF, Seafoam, acetone, etc in an attempt to free rings. It takes a *long* time soaking (and you have to replenish the fluid which either evaporates or drains into the crankcase).

I've had much better luck adding seafoam or MMO to the crankcase and just riding. Could take months or years to work, depending on how many miles you do, but you may indeed discover that compression goes up and oil consumption goes down. I'm sure everyone will tell you that seafoam in the crankcase will ruin your clutch etc. Well, it won't.

You don't seem to have a severe enough problem to warrant any action though. Unless it's burning a lot of oil, smoking, hard to start, etc. then that 135PSI is just dandy. If you ride hard and often and change your oil when you should, you might just find those compression numbers go up without any other action.

You really should torque that cylinder head down properly, though. That alone might get you up to 150PSI.

I probably should torque it but I am planning on taking off the top to swap it with a different kz650 top because I snapped the tach holder. I'll have to look and see what's going on. How is it that rings are stuck tho? I thought they weren't supposed to move?

blink543 wrote: I probably should torque it but I am planning on taking off the top to swap it with a different kz650 top because I snapped the tach holder. I'll have to look and see what's going on. How is it that rings are stuck tho? I thought they weren't supposed to move?

But if you don't torque it now and recheck the compression, then you won't know whether or not you need to worry about replacing the rings when you have it apart...

The rings are split. Basically spring loaded. They ride in a grove in the piston. Carbon buildup and rust can cause them to remain stuck in a closed/pinched position, rather than pressing outward with their full force against the cylinder wall. This allows combustion gasses to bypass the rings (blowby) and enter the crankcase (one symptom being low compression). If it's the oil rings that are stuck, then the motor will also pump oil from the crankcase into the combustion chamber and burn it... This causes more carbon/gunk buildup and further sticks the rings.

There are also usually some oil ports in the piston wall under the oil rings which can get clogged with gunk as well. The only way to get this stuff out is to either remove the pistons and clean them, or to run some kind of solvent (seafoam) through the crankcase (for many many miles).

If you do take the pistons out and try to clean them, you'll see how difficult/impossible it is to remove carbon buildup with anything other than physical abrasion.

Some large percentage of the time, the problem is just this buildup, but it would be kind of silly to take the pistons out and clean them without replacing the rings while you're there....

The rings and the cylinders also wear, but fairly slowly when not abused. Rings can also fail by breaking or loosing their springiness (from overheating).

The "Seafoam Soak" will definitely remove a ton of built up carbon. How I did it:

1) Use the vacuum line between the carb holders with a T fitting and vacuum line.

2) Use some small vise grip pliers to squeeze the vac tube so only a little air gets by,

3) Start engine heat up. Use the line to draw seafoam slowly into the engine adding a little over time.

4) For the final, release the pliers clamp which will suck up all the seafoam quickly into the engine and stall it. Let it sit for about 20 minutes to work, then restart and run until the black smoke stops coming out the exhaust. You won't believe how much burned on carbon it will blow out.

bountyhunter wrote: The "Seafoam Soak" will definitely remove a ton of built up carbon. How I did it:

1) Use the vacuum line between the carb holders with a T fitting and vacuum line.

2) Use some small vise grip pliers to squeeze the vac tube so only a little air gets by,

3) Start engine heat up. Use the line to draw seafoam slowly into the engine adding a little over time.

4) For the final, release the pliers clamp which will suck up all the seafoam quickly into the engine and stall it. Let it sit for about 20 minutes to work, then restart and run until the black smoke stops coming out the exhaust. You won't believe how much burned on carbon it will blow out.

Yeah, but are you basing your statement on the amount of smoke you made, or on actually LOOKING in the combustion chamber?

It's easy to make smoke....

jackleberry wrote:

bountyhunter wrote: The "Seafoam Soak" will definitely remove a ton of built up carbon. How I did it:

1) Use the vacuum line between the carb holders with a T fitting and vacuum line.

2) Use some small vise grip pliers to squeeze the vac tube so only a little air gets by,

3) Start engine heat up. Use the line to draw seafoam slowly into the engine adding a little over time.

4) For the final, release the pliers clamp which will suck up all the seafoam quickly into the engine and stall it. Let it sit for about 20 minutes to work, then restart and run until the black smoke stops coming out the exhaust. You won't believe how much burned on carbon it will blow out.

Yeah, but are you basing your statement on the amount of smoke you made, or on actually LOOKING in the combustion chamber?

I noticed looking through my spark plug holes there's a good amount of carbon built up on the pistons so maybe u are right. They could be stuck

It's easy to make smoke....

Quick question, on retorquing the cylinder studs. Should I loosen one nut then re torque it ? I was thinking I ahould do that following the head torque pattern in reverse. I feel that trying to retorque from where they sit won't yield good results, as the nuts are probably a little stuck

RandomKZ650 wrote: Quick question, on retorquing the cylinder studs. Should I loosen one nut then re torque it ? I was thinking I ahould do that following the head torque pattern in reverse. I feel that trying to retorque from where they sit won't yield good results, as the nuts are probably a little stuck

Yeah. One at a time. Loosen the nut (just enough to break it free, no need to completely loosen it), then torque it to spec and move on to the next one. Spraying some WD-40 on them all and letting it sit for 30 minutes or so will help break them loose without too much effort.