[gnomer43]

Ok, I have a '72 CB500 and I am in the process of pulling the motor, but it is not coming out very easily. I was wondering if I have to remove the oil pan to get it out or should it just come out with the oil pan still on and I am just not manouvering it correctly in the frame? Right now the oil pan is the only thing I see that is still catching on the frame (already removed the breather cover and tach hose) is there something I am missing?

 

[bmartin]

I believe the 500 motor only comes out on the right side (as you sit on the bike). It should pop out without removing anything but the motor mounts.

 

[gnomer43]

thanks, but now I have another question. The odometer has 22,000 miles on it, should I tear into the motor while it is out, or should i just leave it alone. Before I took it out, it turned over with no problems, but it wouldn't crank because of dirty carbs, and I am rebuilding them. Any suggestions?

 

[bmartin]

This is one of most common questions - "should I tear into the engine". The honda 4's are one of the most reliable engines on the planet. 22k on a honda motor is nothing. To answer your question - do a compression test of the engine, if that checks out ok - leave the engine alone!!!!

If the engine has been setting for a while - you may want to dump a few cc's of marvel mystery oil in each spark plug hole, let it set for a night and crank the engine over (with the plugs removed) a few strokes to lub the rings up a little.

Get yourself a good shop manual and do a proper tune-up and ride with the wind. If your going to rebuild your carbs - don't cheap out with a rebuild kit - use a honda NOS stock kit - Don't buy a cheapo kit off ebay. In most cases, all you will need to change are the rubber parts. The stock metal parts should be fine to re-use unless your carbs are real junk.

good luck

 

[HackAsaw]

Have you heard the engine run? Sound good?

Done a compression test? Ok?

I've owned and seen a few low miles inline Hondas that needed a case split with very low miles but pretty much only because they had been unmercifully hole shotted on the strip and the throttles held wide open for pretty much their whole life

If the primary chain is noisy, you may need to go inside if you like the engine that much

me, if it were just another one just like the other one, I'd simply find another to plug and play

goodies inside?

different story

 

[bmartin]

Hackasaw has a good point - if the engine sounds a way off and it's not a matter of tuning, then it would be far cheaper to replace the engine then doing a rebuild. I owned a 72 500 and that little engine was pretty much bullet proof. As a demo for my friends, I use to balance a nickel coin on the engine block and throttle it up to 6 Grand and hold it without the nickel falling over.

One point I'd like to add - under the oil pan is an oil screen filter - you may want to pull the oil pan and clean that screen. If you see tons of metal in the screen - than you may want to question the engine. All and all - your engine should be fine.

 

[gnomer43]

Thanks guys, I appreciate all the advice. As far as the carb rebuild kits go, are the keyster rebuild kits crap?

 

[bmartin]

YES