Popping anyone?

[daves79x]

Good illustration. My hope with Leslie's bike is that exact thing was happening when it got warmed up and he hasn't run it enough to burn a valve. CBX valves clearly don't 'grow' .006 inch when hot, but I'm sure they expand enough to take up .0015 and then some. Only way to know is to shim them properly and see if the compression comes back. We'll know soon. Thanks

Dave

[Kool_Biker]

Here are the preliminary results so far.

img122.jpg

Leslie

Please update us on the progress of this very interesting thread.
So your problem(s) were due to some of your valves being ultra tight .. By now I guess you have adjusted and put everything back .. so how have things improved?

'Popping anyone' was one of the most active threads, read like a detective story, but has abruptly stopped ...

Best, Aris

[EMS]

'Popping anyone' was one of the most active threads, read like a detective story, but has abruptly stopped ...

Best, Aris

See, Aris, here in the United States everybody is very familiar with making popcorn and we all know that the "popping" eventually stops.....

[SPLINTER]

No...I have not yey made any additional progress. We have been in the process of relocating where I work and that has consumed most if not all of my time. I also have been waiting on some parts I ordered that are due to arrive any day now. Next wek I'll continue the work on the bike and will post any progress I make. Hang in there!

[SPLINTER]

OK everybody...here are some results. After shimming the valves and getting everything gapped correctly, cleaned and reassembled, I start the bike and...... the freaking popping is still there. I decided to run the bike for a week and see if the valve in question re-seated it self. Not quite! Although the popping has been reduced somewhat, its still there. Compression on that cylinder still shows extremely low (15 lbs). I know...burnt valve! Isn't that great news . After the bike warms up for a while, the popping is hardly noticeable. I plan on doing a valve job at the end of fall when the weather starts to get cold again. I thought of doing it myself and wonder if having it done by someone else would be a better deal. Anyone care to guess on the cost of a job like that? I will post again the minute I make any progress at all. So... it may be a little while before I make additional headway, but will eventually continue this thread for others future reference. Thanks to all of you who helped along the way. I really appreciate it very much. I'll be in touch!

[EMS]

Once you take the head off yourself, doing the valves is easy, provided you don't need the seats recut or new valve guides installed.
The things you need to watch for:
Proper valve spring compression tool to R&R the valves.
Valve stem seals may be hard to install. Proper tool recommended
Lapping tool required.

Here are a few pictures:

The valve spring compressor is from Summit racing. The small end works perfect for the CBX. The valve stem seal removal and installation tool I had for a long time. Don't remember where it came from. I recommend to use a plastic 35mm film cartridge

You cut the cartridge lengthwise and trim the length to fit the recess in the head to protect the walls from the tools

[SPLINTER]

I'd like to go ahead and re-cut the seats and valves at that time. Maybe go as far as replacing rings and seals, since I'll be there already. Nice pics!

[daves79x]

Leslie:
Well - it was worth a shot. Hope everyone reading this thread sees the value of checking valve clearance. On your bike, I'd just pull the head, and if it's an exhaust valve (probably is), I'd just get the new valve, try lapping it in (unless there is visible seat damage), and if that works - let it go at that. If you wanted to go further, all I'd remove are the exhaust valves, lap them and install new seals (you'll destroy the old ones anyway). The intakes usually look pretty good. So a couple of tools, a new valve and seals, and $120 for a head gasket should fix you up. I wouldn't go any deeper. Pulling the cylinder off is just a lot more work and you need some more tools to reinstall it. If the bike has the compression you noted (except for #2) and doesn't smoke or use much oil, I'd not go any deeper.

Running the bike a lot with a known burned valve could damage the seat further and lead to more expense. What you need done is just a weekend job. Good luck and ask away if you need more help.

Dave

[CopperCollar]

Here is a source for the Valve Seal Remover

http://www.sears.com/shc/s/p_10153_12605_SPM222409654P

http://www.amazon.com/Schley-Narrow-Acc ... B000M1F5CA

Good thread for reading, at least for me.

Mike