Cylinder head side cover 1980 CB750C

[realjakebaker]

So, I am in the process of rehabilitating a 1980 CB750 C that was abandoned for two years. It is almost all stock, and it is my first bike, so I am learning a lot about motorcycles and their maintenance. I am having an issue with the charging, but I still haven't gotten around to putting a volt meter to the rotor and stator in the alternator to check for continuity/bad rotor. I am having an issue with a high idle after the bike warms up, but I still need to spray some whatever around the carb boots to check for an air leak. I am having an issue with the choke not being "floppy" enough for that little baby spring to activate it when the choke is pulled, which is probably going to lead to me pulling the carburetor again (GAH! I had a hard time getting it back in there after the last time I pulled it to clean the carbs and replace the jets n'at. I ended up putting the boots that go from the carb to the air box on the carb before trying to get it into the engine boots, and then shoving them in the air box after everything else was all situated.)  I need to tension the cam chain and make sure my spark plugs are properly gapped. But I am confident that I can do all of those things and get the bike back together.

The reason I am posting is because it looks like the previous owner might have dropped the bike and one of the cylinder head side covers (#2 at this link http://www.partzilla.com/parts/search/Honda/Motorcycle/1981/CB750C+A/CYLINDER+HEAD+COVER/parts.html) is dented in and no longer flush with the rest of the cylinder head cover. It has some movement to it if I press on it. Basically, I wanted to get someone's opinion before I took a screwdriver to that bad larry and pried it off. What am I going to find under there? Am I better off just leaving it? Should I spray carb cleaner on it while I am testing for leaks at the boots to see if that is where the leak is? Can I replace it without taking off the entire cylinder head?

I would hate to do all of these other things and still have a bike that runs like junk because this little $12 silver dollar sized cap is dented and wiggly. I REALLY don't want to start dismantling the engine, because that will result in me opening a whole new can of worms, I'm sure. Every time I fix something, I seem to find something else that is wrong.

The good news is that the bike starts and runs if the battery is mostly charged, and  despite the high RPM I can ride it around a bit, but I have probably only ridden it for an hour total.

Thanks for any advice.

[Beekeeper]

As long as it's not leaking oil through the VC gasket at that point, I don't think you have anything to worry about.  The VC gasket actually forms a sort of pocket around that end cover, and the end cover sort of hangs on a lip on the head.  I'd source one or more if you need them, and if it bothers you, swap it out when you adjust the valve shims at the proper interval.  Offhand, I think the shims should be run and adjusted every 5000 miles.  I wouldn't pry it out the end though, because you have to pull the VC to replace it.  Most certainly head and or VC damage would occur if you start prying on it.

[realjakebaker]

Doesn't look like it is leaking anything, so that is a good sign.

Things I figured out tonight:

1. There is a small air leak at the #4 carb boot. Found it out by spraying a bit of wd-40 on the boot while idling, engine revved way up. Tried it on the other boots and did not get the same result. Rode the bike around for a bit and cinched the hose clamp down a bit further. Did not try to spray anything else on it, so I will try that method again later.

2. I have been having an issue with the bike idling way too high, and I think it begins and ends with the choke not working properly. The arms are not seated correctly. When the choke knob is pulled, the big hook that the cable goes in moves up, but the smaller brass choke arms do not move with it. I have to set the idle screw high to get the bike to start and not gutter out in idle when it is cold, but when the bike warms up the idle goes up, and the screw can be turned way down. If the choke worked properly, I imagine it would get rid of this "high idle, then start, then drive, then reduce idle" process that i've been going through. Everything needs to be re-seated, which will be near impossible to do with the carbs on the bike. Sigh.

3. Another issue about getting the bike to start reliably seems to have just been a very dirty air filter. I let the bike pull naked air tonight, and it seemed to run much smoother and start much better. The bike also works much better with the fuel petcock on.

I did not get around to adjusting the cam chain or getting an resistance reading on the rotor/ checking the stator for continuity. I am on another message board for riders in my area, and I am hoping one of them will let me borrow their motion pro tool and perhaps be kind enough to show me how to use it and maybe even get my air-fuel mix down. Other problems for other days.

[Beekeeper]

The idle problem are usually related to vacuum problems, which you know you have at least one bad carb holder.  Also, the proper paper element is required for the CV carbs to operate properly.  If the bike has been parked for a couple years, then I would guess the valve shims have been neglected, and need attention.  You can hit the cam chain adjustment at that time also, and swap that end cap too.  These old Hondas remind me of flat heads.  Usually, if you can turn them over, they will run, unless they have been severely neglected.  You know yours will run, but to run well, needs attention.