[singhg5]

When I checked mine a little while back it was in the 130 range, well above spec.

@Scott:

On your C5 I think there is no kick start lever so you must have used electric start button to do the test.

Did you disconnect electric power supply to igniton coil or/and fuel pump while doing the test ?

[Ducati Scotty]

Correct, no kickstart.  I didn't disconnect anything.  Pull plug, peg throttle, hit the start button and measure.

The ignition wouldn't matter, the plug is out.  With the fuel pump connected there may be som fuel going into the cylinder but that shouldn't matter.

Scott

[singhg5]

I consider 80-85psi too low.

If I got that reading on an Iron Barrel, I'd be taking the head off to see what's wrong.
And an Iron Barrel only has 6.5:1 compression.

@ACE:

What is the range of compression pressure you see in iron barrel ?

There may be some head gasket leakage in my bike, since normal range is 90 to 110 psi in RE Service Manual.  

It is good that Scott tested his C5 so we can compare our EFI bikes and his
130 psi may not be all bad. There may be variation in gauges and perhaps some effect of method used. Ideally one should do same test when bike is relatively new and then at a later stage (say after 10 or 20K miles) so that any changes in engine can be detected.

[Arizoni]

I suspect the iron barrel and the AVL will have higher compression readings if for no other reason than they do not have an automatic compression release that's holding the exhaust valve slightly open at very low rpm.

Actually, I was rather surprised the UCE would have a compression as high as 110 psi because of this auto comp release.
Learn something new every day.

[Ducati Scotty]

I wondered if maybe my auto-decomp wasn't kicking in because the motor was spinning too fast and if that's why my reading was so high.

Scott

[Ice]

 Or pull the plug and squirt in some Sea Foam and wait 20 minutes then reinstall and fire it up.

 Do this at night and only at night.


 To see in broad daylight the cloud that comes from the tail pipe for up to 30 seconds might cause a hart attack.

[ace.cafe]

@ACE:

What is the range of compression pressure you see in iron barrel ?

There may be some head gasket leakage in my bike, since normal range is 90 to 110 psi in RE Service Manual.  

It is good that Scott tested his C5 so we can compare our EFI bikes and his
130 psi may not be all bad. There may be variation in gauges and perhaps some effect of method used. Ideally one should do same test when bike is relatively new and then at a later stage (say after 10 or 20K miles) so that any changes in engine can be detected.

The Iron Barrel typical range is 110-115psi for a stock Bullet.

[Maturin]

What about the power output of your Bullet, Singh? Did you recognize any changes? If piston rings or valve stem seals go weak, that should have some influence, aswell as you should have some blueing from the exaust when closing the throttle at high revs.

[TWinOKC]

What about the power output of your Bullet, Singh? Did you recognize any changes? If piston rings or valve stem seals go weak, that should have some influence, aswell as you should have some blueing from the exaust when closing the throttle at high revs.

+1  

I would think you would notice a loss of power?  Maybe top speed would be a little lower?  If there is no loss in power I would leave it alone.

[Ducati Scotty]

I'd recommend a few things.

1) Do your compression test as before but then also do it with 3-5ml of oil while the engine is warm.  If your compression goes up significanlty this may be an indication of worn rings.

2) Do a leak down test.  You'll need a leak down tester ($50 at Harbor Freight) and an air compressor.  It's like a compression test but using the air compressor to fill the cylinder with compressed air.  Then you see how quickly it escapes to tell how well the rings and valves are sealing.  In addition to the pressure readings just listening at the intake, exhaust, and oil fill plug for a hiss can tell you if air is escaping from the intake valve, exhaust valve, or rings, or any combination of them.  Even listening without the gauges can tell you this sometimes.  You can do that much with just a compressor and the fitting you already have from your compression gauge that fits in the spark plug hole.

Scott

[clubman]

I guess it must be a misprint. This is the same owner's manual which recommends I lubricate the chain "every 3,000 kms or earlier as required"  

It's a misprint. Mine only has the D at 18.75m too. The chain lubing is the same as yours though. To be fair, if they are thinking of the old fashioned way of placing the chain in boiling wax you might just get away with 3,000km intervals. I have been using this method for the last three thousand miles and it is superb, though I do it every 1,000m. Thus far the chain has required no attention at all between maintenance sessions.

[2bikebill]

Boiling wax? Streuth!  I reckon I'll stick to the squirt & go method every 300 miles or so ....

[clubman]

The chain maintenance equivalent of convenience food, mate! It's just not authentic! 

[2bikebill]

No it loves it - really. Now & again I get a can of paraffin and the wife's toothbrush and give it a good scrub too. Quick wipe before a good dowsing with Wurths Dry Lube and off I go. Simples 
Boiling wax?    Surely there's a law against it.....   

[clubman]

Paraffin and the wife's toothbrush - now you're on the right track! Here's what you need to do when you decide to complete your journey back in time. It's fun - really! You'll feel really noble once it's done. 

http://www.putoline.com/en/products/catalogue/segp_offroad/pchmp/559/off-road/chain-maintenance-products/chain-wax/