Compression Test

[trionyx]

Hello Way,
My advice would be not to remove the cylinder head..Instead of that buy a transparent appr. 30cm long i.d. 3mm tube (SMC makes it), connect it to a compressor. Turn your engine to TDC position, put the tube into cylinder through the spark hole and blow it out by the compressed air. Even if you cannot blow it out, it moves, maybe you can remove it by "sharpened" screwdriver after directing the eraser bellow the spark plug hole. (Keep the tube vertical to have enough space blowing it out.) That's the easiest way...

[5th_bike]

,,,or put/hold a piece of plastic hose at the end of a vacuum hose and try and have it suck the eraser to it, to fish it out.

[Way]

Oh man, thanks guys!

I've got one of those little portable air tanks from a long time ago that I hooked an air nozzle to so that whenever I change spark plugs or need to clear dirt/dust from something, I can just blast it out. Didn't even think of using it for this.

I could also rig up some tubing to hook to my shop vac if need be. Glad I checked back before I got everything apart. It's nice having others around who can think for me when I have a brain cramp. :drool:

It's raining out right now, I was clearing a space in my walkway so I could bring the bike under cover. Now I have to have the patience to wait till it stops raining.... :whistle:

[OldNTired]

Originally Posted by Water Warrior

Sounds like you will be getting your learning curve increased whether you want it or not. Best of luck and do keep us in the loop.

After reading your posts, and all posts after the one by WW, I think the best advice you got WAS from WW.
Now, I'll give you some:
1. keep track of which cyl head cover bolts come from which holes.
And 2. Break down and spend the $5 on a 22mm socket!
and 3. Remember the top bolt will NOT come out (or go back in) if the cyl head cover is flat
on the cyl head.
Have a new cyl head gasket handy, and a good sealer for the head cover; I used Hylomar, and it is great. I know there are other good ones, but this stuff is the best I've ever used.

[jonathan180iq]

I would vacuum. Don't blow. You could inject debris or other crazy things into the engine.
VACUUM.

[mrlmd1]

Fill it up with oil, maybe it will float out. Then siphon or suck out the oil.

[Way]

Well I spent an hour or so yesterday trying to clear out the cylinder but not sure about the success.

Jonathan, I unfortunately did blow out the cylinder. I understand and agree with your point though. I kept the piston at TDC on the compression stroke so both valves should have been closed. I'm hoping that kept stuff from going into the engine.

Speaking of that stuff, I did get a few wood bits to blow out. I did not however see or hear anything else bouncing around in the cylinder. It makes me wonder whether that pencil had an eraser on it or not, though I'm sure it did, just not as sure as I was because it seems I would have seen something bouncing around in there. It was getting dark and I just grabbed what was in with the tools.

The vacuum was a good idea, but I did not see anything come up through the clear tubing.

Mrlmd1, that is an excellent suggestion. I will try that next. I have a cheapo turkey baster, (the kind with the squeezable bulb on the end) that I can use to suction with. That will be my last attempt.

OldNTired:
Are you thinking I should just give up on the compression test and remove the head? Please elaborate as I've read WW's posts.

1. Will do. I've got some cardboard I can punch some holes in to keep them in order.

2. The fit of the 7/8 is actually pretty good and the resistance to cranking with the spark plug out is not so bad as I think it's going to mess up the crank bolt. But, yes, I suppose I should let the moths out of my wallet.

3. Is Hylomar a UK product? I did a google search and believe it's called Permatex here Stateside which is pretty commonly available. Which type do you recommend for the GZ250?

Thanks fellas

[OldNTired]

Originally Posted by Way

Well I spent an hour or so yesterday trying to clear out the cylinder but not sure about the success.

Jonathan, I unfortunately did blow out the cylinder. I understand and agree with your point though. I kept the piston at TDC on the compression stroke so both valves should have been closed. I'm hoping that kept stuff from going into the engine.

Speaking of that stuff, I did get a few wood bits to blow out. I did not however see or hear anything else bouncing around in the cylinder. It makes me wonder whether that pencil had an eraser on it or not, though I'm sure it did, just not as sure as I was because it seems I would have seen something bouncing around in there. It was getting dark and I just grabbed what was in with the tools.

The vacuum was a good idea, but I did not see anything come up through the clear tubing.

Mrlmd1, that is an excellent suggestion. I will try that next. I have a cheapo turkey baster, (the kind with the squeezable bulb on the end) that I can use to suction with. That will be my last attempt.

OldNTired:
Are you thinking I should just give up on the compression test and remove the head? Please elaborate as I've read WW's posts.

1. Will do. I've got some cardboard I can punch some holes in to keep them in order.

2. The fit of the 7/8 is actually pretty good and the resistance to cranking with the spark plug out is not so bad as I think it's going to mess up the crank bolt. But, yes, I suppose I should let the moths out of my wallet.

3. Is Hylomar a UK product? I did a google search and believe it's called Permatex here Stateside which is pretty commonly available. Which type do you recommend for the GZ250?

Thanks fellas

Well, maybe I misunderstood, maybe I'm dumb, but it sounded to me like the end of the pencil broke off. That means that there is an eraser, and that cheap metal fastener, and some wood sitting in the cylinder. Trying to get that out of a spark plug hole, even if possible, is not going to easy or fast. Personnaly, I don't think that it is possible., because of the angles involved. It would frustrate me to the point of using an 8LB sledge on it!
Good idea with the cardboard!. And you are right, it doesn't take much to turn the engine over without a plug in there But, buying a tool you will use again is never a bad investment. And yes, Hylomar is a UK product. But between my son and I we have used every Permatex product we have found, and Hylomar beats them all for this kind of thing. Permatex used to be my favorite, but the Hylomar is only $1 more and is better. Over half the parts stores I've been in carry it, and I'm in the States. Plus, you can also use it as a replacement for LocTite.

[Way]

I just wasn't sure what you were addressing as far as the compression test was concerned and just wanted to know your opinion. Thanks!

I was thinking to try one last time using mrlmd1's suggestion but I'm wondering if it's worth the mess versus just taking the head off and knowing what I'm dealing with for sure.

Regarding this:

3. Remember the top bolt will NOT come out (or go back in) if the cyl head cover is flat
on the cyl head.

Do you mean to take out all the other bolts first and then tilt the cover so I can remove the top bolt? Or do you mean that all the other bolts come out all the way but the top bolt can only be unscrewed so far but never comes completely out while on the bike? In other words, I can remove all the bolts except the top one, but can loosen it enough to slide the cover off sideways..

Sorry for the questions, it may be that you're not the one who's dumb.. :tongue:

[mrlmd1]

It's much easier to fill it up with oil and see if anything floats out. Or washes out if you inject it with the turkey baster. If there's no debris or anything in there, that's a lot easier and less messy than taking the top of the head off.
You can also ask around different mechanic's shops if anyone has a fiberoptic 'scope to look inside the cylinder. Maybe you could borrow or rent it, or bring the bike over to the shop and let them look inside the cylinder.

I would do the oil thing- that's the easiest.