you need 75psi+- just to run.. the fact it went up a bit with some oil in the cyl indicates rings are worn, but that is still CRAZY low psi. Did you have the throttle open when you were cranking ? having the slides closed off won't allow much/any air in while cranking, and results in low numbers, but those are really low.
Min spec for a 3rd gen r6 is 185PSI with butterflys held open, and a warm motor.. Warm or cold won't make much difference, around 5psi or so. Also, slow cranking will lead to low numbers, ya need a good strong battery.

I would get someone to do a leak down test.. that will be more telling. Considering ALL your cylinders are crazy low, that would make me think it's just something up with the way you are testing.. If 3 were 180psi, and 1 was 80psi, then i would believe that cyl has a major issue. OR, the motor really is in a bad way

 

... me think it's just something up with the way you are testing.. If 3 were 180psi, and 1 was 80psi, then i would believe that cyl has a major issue. OR, the motor really is in a bad way

I can post a video of how I am testing if you would like? I don't really see where I went wrong with the compression test. It seems pretty straightforward.

 

Yes throttle was wide open.

It's a 99-01 R6 with 34k miles.

Compression test was a cold motor.

I had a jump box connected to the battery to be sure I was getting a lot of power, so that shouldn't have been the problem.


Let me know what you think!

 

Bump! Someone please help me.

Maybe timing is off? I don't know how to check timing.

 

I would start with - timing - valve clearance


Then warm it up and do the test again

 

How do I check timing? All the threads I seem to look at are too old and the pictures are gone / bad links etc.

I'm guessing I pull off the top cover to expose the timing chain?

 

http://www.r6messagenet.com/forums/...forums/r6-maintenance-technical/39254-r6-service-maintenance-repair-manual.html

Heres the manual. Figure out the rest

 

Can you at least help me understand what's going on?

Is it the timing? Or the rings?

I looked through the manual briefly, but I will need to look at in depth to find out how to do the timing. I will have to do it later.

 

valve clearance too.. if you are checking timing, the cover will already be off and you can check valve clearances at the same time. if some of them are zeroed out, that could be part of the low comp issue.

 

I think he wants one of us to go do it for him

 

Before doing anything try to have the motor warmed up before doing the compression test. Metal expands when it hot/warm. As I believe you did the compression test when the motor was dead cold right.

 

as i posted earlier , that is only gonna make about a 5+- psi change. I have done many compression tests, hot and cold, on many year r6's. That is about the diff from cold to hot you will see. Yes, you should do it after running the bike, but it is not going to suddenly take his readings from 80psi to 180psi. You will see a significant difference (low reading) if you don't hold the throttle open, or hold the butterflys open (3rd gen fly by wire).

I think he wants one of us to go do it for him

wouldn't that be convenient !

 

If you need a motor, I've got one. And it works too.

 

Pm sent

 

Don't get a new engine. Tight valves may stay open causing low compression. put all the exhaust vlaves back to spec and try again.

 

Don't get a new engine. Tight valves may stay open causing low compression. put all the exhaust valves back to spec and try again.

Ok not sure how to do this but I will do some more research and read the manual to try to figure it out.

 

Exhaust are too tight..

 

I also find it hard to believe that you are getting such low readings on an engine that runs and idles fine. Also carbs can be difficult to clean. Even the smallest of dirt can clog a jet and cause fuel to not enter that cylinder. But at the very least I'd get those exhaust valves fixed and report back after that. Don't toss the motor just because you are frustrated.

 

Not the best audio but sounds ok. Have you checked to make sure you are getting spark to the troubled cylinder?

 

Getting spark, getting fuel, getting everything. If you pour fuel into cylinder 1, starts to run and sound better. So I tried adjusting screw on that carb, works better but still header is just warm (Can't unscrew the screw anymore). So I'm not sure what the problem is. I sort of messed up, cross threaded main jet holder thing, so I ordered new ones about a week ago. Should be here any day now and I can change that part out. When I adjust clearances, and put new carb parts in, hopefully my problem will be fixed!

I mean I guess I could adjust idle jet.. But that doesn't really make sense to have one idle jet way higher than the others?

 

Remeasured. Just in case. I think I was doing it a little wrong last time.

Also carb parts came.. so that's figured out. Hopefully after I adjust valves, compression goes up! And all my main problems are solved! Finger's crossed!

I need to go buy shims on Tuesday.

 

So I downsized my shims by 2 sizes, from 184 to 175.. and you would think it would be in spec now right? Nope. Compression is now 100... but clearance went from .152 to .17... so I need to go exchange for even thinner shims. All headers are running hot now which is good (I think that's because of new jets, and barrels for the carbs). But if PSI jumped that much higher, I'm sure when I'm in spec.. my problem should be fixed.

I did measure all the shims, and they are what they say they are in mm.

So old clearance measurement was 0.152 and old shim was 1.84. I changed out that shim with a 1.75. So, 1.84 - 1.75 = 0.09
Now we can add 0.09 to our old clearance number to see what the new clearance will be: 0.152 + 0.09 = 0.242 which is in spec, great!

Now, why is the clearance at 0.178? HUH? I'm super confused. Where am I going wrong?

 

If you put a 175 shim in there your clearance should be .24 which is good. Where is that 178 coming from

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I measured the clearance again after I put it all back together and that's what I got .178, but it should be .242 which is why I am confused.

 

Measured the old shims you took out too? Sure your setting the cam timing properly?

 

Yes the old 184 shim measures to be about 1.84mm
The new 175 shim also measures to be 1.75mm

I think my timing is dead on basically.. I followed the manual.. Unless the manual is wrong? Lined up the lines on the cam sprockets, and the line on the bottom with the circle thing.

Should I go exchange my shims for even thinner shims?

 

For the measurements to be that off I'm going to guess your measuring wrong or not properly setting TDC for each cylinder. Can't tell from this side of the screen though. But if you think you are doing it right always go by the final measurment. If it is still off get the other shim.

 

I guess I could make a video, I think I'm following the manual exactly. To make sure I'm at TDC, I shined a light down the spark plug hole and cylinder 1 is definitely much higher than the others. Plus the camshaft lobes are facing away just like the manual says they should be. I am measuring the distance between the top of the valve bucket and the lobe. Let me know what I am doing wrong.

 

Ok get the cam lobes facing 11 and 1 o'clock. Use your feller gauge to get a measurement between the valve bucket and the cam lobe.
it doesn't have to be a tdc to measure clearance as long as the lobes are like stated above. You do have to set it at tdc to get the timing right when putting it back together.

Ex. clearance is .15 and say you want .20. The valve shim is a 1.80 when you measure it, so you want more clearance so you go to a smaller shim. A 1.75 shim would give you the .20 you want.

Do that for each valve. Then time it ***follow the manual with the timing marks and turn it over by hand to ensure its good. Valve hitting a piston will be very costly if you start it like that.

button it up, fire it up, sit back drink beer. Done

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Ok get the cam lobes facing 11 and 1 o'clock. Use your feller gauge to get a measurement between the valve bucket and the cam lobe.....button it up, fire it up, sit back drink beer. Done

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That's basically exactly what I did... Now why are my measurements off?

 

Well... I reshimed everything. I'm in spec. And guess what? My compression is about 80 in every cylinder. I guess new engine.

Factory calls for exhaust to be 0.21-0.30 and for intake to be 0.11-0.20.

All exhaust valves are 0.229
All intake valves are 0.152