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Discussion Starter #21 (Edited)
Reuslts of a compression test /cold engine, 1 spark plug out of each cylinder, battery fully charged, full throttle/: Front 110 psi, Rear 115 psi.

Same procedure with hot engine, both cylinders on 110 psi. Put a little syringe of engine oil into each cylinder /3ml/ - both are reading 120 psi.

Those values are way below specs, so I have to figure out what to do next. Got some borescope camera too, looked inside, no traces of valve / piston hit so I guess timing is good.

Valve open maybe? But how? Rocker arms can be slided sideways after torquing cylinder head + cover to specs.

Coolant level is the same as it was when I put engine in the frame, no bubbles or any unusual pressure in coolant.
 

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1999 Shadow 750 ACE VT750CD3 Modified
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I'm sorry to hear this. I think the valves do sound most likely, the compression is going somewhere.
I think the next will be a leak down test, although I might just bring it up to TDC and put it in 5th gear use an air line to pressurize it to see if I could hear where it's leaking, I'm guessing the intake valves based on the previous behavior. I wish I could give more advice, but the hydraulic adjustment of these valves is beyond my understanding.

I wish you luck and hope it is a simple solution.
 

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Discussion Starter #23
TBH I used el cheapo compression tester from ebay borrowed from my neighbour which has a long hose without one way valve / real crap but its all I can borrow on sunday /.


So the reading is way off I guess. Tomorrow I will visit a friend of mine to borrow professional one and take another measurement. Keep you posted guys, thanks.
 

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‘Again’... Okay, when did you last test it, and what were the results? (Nevermind, just read the newer posts!)

Testers can be off, and the 1-way valve is nice, but so long as you can sustain cranking and watch the needle, it should be fairly accurate. You could try testing it with an air compressor, if you have one. In my case, my front cylinder wasn’t firing. Just reworking the heads by relapping the valves and making sure the hydraulic tappets were adjusted brought it back.
 

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Did you open the throttle???
Mine were very low till i opened the throttle and they came up at east 50 pounds.
Check it again= Strong battery or jumped, Open throttle, 8 puffs. See what it says.
 
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Discussion Starter #26
Sorry guys for late reply, been a little busy lately. As I said I borrowed hi tech tool to measure compression and here are the results:

Cold engine, 1 spark plug out of each cylinder, full throttle, fully charged battery

Front cylinder: 178 psi +- 5, Rear cylinder: 180 psi +-5

Now I am suspecting my diy mufflers doing this, time to unmount them and leave just a straight pipe what happens.

Any other ideas?
 

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The only thing DIY mufflers would do, the same as straight pipes, or NO pipes, is run the engine lean on fuel. Unless your pipes were blocked with something, which would create too much of a restriction.
 

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Discussion Starter #28
My mufflers are not anywhere near straight pipes, that is probably the problem I have. i have possible pressure build up in there in open throttle.
 

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Quick test we used to do on cars that we suspected had a plugged cat converter is to disconnect at the header pipe and if it runs strong then you know.
 

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Discussion Starter #30
Today I started my engine with both mufflers off, still the same. Last thing are the carbs.

I mean when compression and timing is good, no stuck valves and electrical things are OK it the last possibility.
 
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