Carb synchronising issues

[gtmdriver]

Fair enough. It may be an iffy gauge, but if it reads at all on the Beemer why isn't it reading on the Honda?

Have you tried just sticking your thumb over the plughole during cranking to see if there is any compression at all?

[El__burro]

I had the same thought, yes it has some pressure, i am trying a way to test the gauge, probably with an air compressor?
I am about to buy the tester that mikethebike suggested.
thanks
el__burro

[El__burro]

I was looking at this video I shot the other day (out of frustration) and I have realised that the smoke from the exhaust is blueish.
After that I checked for oil leak and I've noticed that the tacho drive leaks from the screw is supposed to hold it in place but even worse I have oil just under exhaust one, can't tell if is the exhaust bearing or the gasket.
regards
el__burro
http://youtu.be/xfHjuVb1dyE

[El__burro]

Have I found a way to test the compression gauge?
I took a compressor for tyre and attached it to the gauge.
At its best the numbers on both gauges matched. (sorry for the awful picture)
it was 75 PSI
Unfortunately i had to push the compressor pipe in the terminal without any extension otherwise it would not read anything.
Also the 2 compression tester gauges show that one is not working properly.
I have run another test with engine warm still ZERO.

el__burro

[gtmdriver]

So could it be the gauge extension that is causing the problem then?

I can't imagine that an engine could be so worn on every cylinder that it would have absolutely zero compression pressure.

[mike the bike]

The engine wouldn't fire without decent compression.   When air is compressed it gets hot because the same amount of joules have to occupy a smaller space.  More compression = more heat.

[El__burro]

Thanks,
what about the smoke in the video, is it blue? does it mean a blown gasket?
Since the bike starts nicely, I guess the best option
is a brand new tester as suggested above by Mikethebike.
Thanks

el__burro

[hairygit]

Blue smoke is burning oil, most common causes being damaged/ worn bores/pistons/rings or valve stem seals/ guides worn 

[El__burro]

thanks Hairygit, I guess that in any of the above cases the engine must be taken out of the frame?!
It's not good news!
Thanks
el__burro

[hairygit]

On a 750 I'm afraid so. But if you can get a decent compression tester to get a set of readings it will tell you which cylinder is causing the issue, or all of them if it's general wear. Don't despair though, they are easy enough to work on, the hardest part is getting the engine out and back in again if you're doing it alone. If you can get somebody half sensible to help lift it out and back in it's surprisingly easy!

Sent from my X5 using Tapatalk

[MarkCR750]

And if it's not smoking badly during normal use don't do anything!, you were giving it plenty of revs on that video, cracking the throttle open etc , had it been stood for a while before the video?, anyway burning a bit of oil won't hurt anything, wait til it get worse then strip it down, my guess would be a bit of valve guide wear.

[El__burro]

Good day,
not good news, I guess.
I've received and used the new compression tester,
tried a first test at cold
C1 and C2 = 8 bar (115 psi)
C3 and 4= 7.5 bar (105 psi)

then I started the engine and warmed it up for 5 minutes,
Could only measure C1 and C4 as they are the easiest.
Both measured 9 bar (125 psi)
I've read that it should be between 10-12 bar (150-175 psi).
Could this improve by running the bike for longer?

Any opinion?
I guess I need to start looking into new rings, a new full set of gasket and other issue that may come out.

Regards
El__burro

[Chris400F]

Glad you now have a working compression tester.
Might be interesting to try it on your BMW and see what readings you get.

[El__burro]

Thanks. I'll do that tomorrow.
Could it be anything to do with the exhaust copper gasket?
El__burro

[mike the bike]

That's better than the readings on my GS650;   35, 105, 100, 105. .   Worn out with a capital F methinks.