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No compression?

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OK, so no more clicking, the timing is set by the manual, it spins freely, all put together. Go to start it and... the starter spins, sounds more high pitch than usual. I assume because there is nothing resisting it, so no compression?
All the bolts are fitted tight, the crankshaft and camshafts spin... but doesn't start. I did not replace the head gasket (I know, I know, I should. I wanted to see if I could get by with the same one. I should hopefully get money tomorrow, so I can go buy one).

Here's a video for reference: https://vimeo.com/521670017
 
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You can take the plugs out and feel with your finger if its moving air if you don't have a compression tester. Other than that, check for fuel/air and spark.
 
Jimmbuzz said:
You can take the plugs out and feel with your finger if its moving air if you don't have a compression tester. Other than that, check for fuel/air and spark.
Click to expand...

I don't have a deep socket to undo the spark plugs. I have to go buy one.
 
Not sure why you would attempt to start the bike without the valve cover on. Also not clear how you would check compression but with a compression gauge in the spark plug hole. Spark plugs that you haven’t taken out of the holes. :confused:
 
Rich82GS750TZ said:
Not sure why you would attempt to start the bike without the valve cover on. Also not clear how you would check compression but with a compression gauge in the spark plug hole. Spark plugs that you haven?t taken out of the holes. :confused:
Click to expand...

It wasn't catching, so it wouldn't start. I had to see if the camshafts were turning while the starter was engaged. It sounded higher-pitch than normal, so at I thought something wasn't turning properly.
 
the cams may be 180 degrees out of phase so no compression. It's easy to do.
 
Nessism said:
the cams may be 180 degrees out of phase so no compression. It's easy to do.
Click to expand...

Is it that simple? Could you elaborate? I can go get a picture of the camshafts.
I followed the guide set in the manual: Advancer set to T, 1 on the exhaust cam flush with the area where the cylinder head and head cover meet, 2 pointing upward. 20 pins over to the intake cam, where 3 is pointing. I'd upload pictures, but it keeps saying upload failed for some reason. I try an image link, that fails too.
 
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Doesn't sound too strange.

ZombiePotatoSalad said:
I don't have a deep socket to undo the spark plugs. I have to go buy one.
Click to expand...

Do this, otherwise you can stop wrenching on your bike (You'll need one anyway to maintain your bike).

As usual, one needs air (and compression for ICE), spark and fuel to get combustion An old trick is to drop a teaspoon of fuel down the spark plug holes, this gets most engines to fire (for a few revolutions).
If not, you'll know that either there's an issue with the ignition or compression (or both), and can go from there. If it does, you can begin troubleshooting the carbs.
 
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roeme said:
Doesn't sound too strange.



Do this, otherwise you can stop wrenching on your bike (You'll need one anyway to maintain your bike).

As usual, one needs air (and compression for ICE), spark and fuel to get combustion An old trick is to drop a teaspoon of fuel down the spark plug holes, this gets most engines to fire (for a few revolutions).
If not, you'll know that either there's an issue with the ignition or compression (or both), and can go from there. If it does, you can begin troubleshooting the carbs.
Click to expand...

I originally had one, but lost it when we moved.
 
ZombiePotatoSalad said:
Is it that simple? Could you elaborate? I can go get a picture of the camshafts.
I followed the guide set in the manual: Advancer set to T, 1 on the exhaust cam flush with the area where the cylinder head and head cover meet, 2 pointing upward. 20 pins over to the intake cam, where 3 is pointing. I'd upload pictures, but it keeps saying upload failed for some reason. I try an image link, that fails too.
Click to expand...

When you set up the cams as described, did the notches on the right hand side of the cams point inwards towards each other (correct) or outwards away from each other (not correct)?
 
2BRacing said:
When you set up the cams as described, did the notches on the right hand side of the cams point inwards towards each other (correct) or outwards away from each other (not correct)?
Click to expand...

Towards. I'd post a picture if I could.
 
Go buy a spark plug wrench and remove the #4 plug. Put your finger over the hole in the cylinder head and spin over the engine to see if you have any compression. If not, either the valve(s) are open or the cams are timed wrong.

Set the crank to 1-4T and then look in the cylinder and make sure the piston crown is at the top of the cylinder.
 
As I turned the engine manually, I heard what sounded like a hiss coming from around the left side of the engine.
 
Ok, I do feel compression when I put my thumb over the #4 spark plug hole. But it doesn't feel very strong. Like, not enough to launch a spark plug.
 
Spray some soap water all over the head and cylinders and crank it. If the head gaskets blown youll see bubbles wherever theres an air escape.
 
IF IT WERE ME........ I would take the head off, inspect for bent valves, and reset the cams. ALSO if you look at each shim bucket with the cam lobe facing up from the bucket you should see a lot of gap between the cam and the bucket if a valves bent...they tend to not let the bucket come all the way up like normal.
 
chuck hahn said:
IF IT WERE ME........ I would take the head off, inspect for bent valves, and reset the cams. ALSO if you look at each shim bucket with the cam lobe facing up from the bucket you should see a lot of gap between the cam and the bucket if a valves bent...they tend to not let the bucket come all the way up like normal.
Click to expand...

When you say "reset the cams," do you mean to take them out and redo them in the same way, according to the manual?
Remember, I'm autistic, you have to be descriptive.
 
It sounds like you're missing compression, you shouldn't be able to keep the spark plug hole closed with your thumb (given a compression stroke).

To be sure, you can borrow a compression tester (or buy a cheapo one, should be sufficient).

The hissing noise usually is a cylinder sucking in air, so given your reply re. the notches one could assume that your cams are at least close to correct timing.
 
Yes...by reset i mean reinstall them after checking things out in the head ( bent valves or damaged valve seats ). Following the manuals directions of course.
 
Just got the head gasket today (was supposed to arrive on the 16th). When daylight comes, I'll head outside and put it on.
 
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