Topic: Reviving a CB750A - Should I drop the pan - for preventive maintenance?

[raymond10078]

BACKGROUND:

I have a 1978 CB750A (~15,000 miles) that is being brought back from the dead.  The bike sat for 10+ years before I bought it.  The oil was very black.  Replaced oil and filter.  My original plan was to run it for a short while 50-100 miles, and change the oil and filter again (this plan was due to the fact that when you change the oil an a "A" bike, about 20% of the old oil stays in the converter, etc, and can't be drained out - if I change the oil twice, about 6% of the old oil will remain).
 
So far, I've ran it for about five minutes total (stationary).

I'm thinking about dropping the pan, just to see what is in there - maybe to clean out what had settled there over its years of sitting, and the make sure the screen is clean.

Is this a good idea, or does it invite unnecessary risk (broken bolts, etc)?  Would you do it?

UPDATE - THE ANSWER:  Dropping the pan to clean the pump inlet screen is a recommended periodic maintenenance item (every 12 months or 6,000 miles), per the Owner's Manual.

[Simpson]

I think its a good idea with little risk. This winter i finally pulled the pan on my K0 and it came with a piece of mind to be able to inspect for metal shavings and plastics tensioner plastics parts. I was also able to get a glance inside to other areas for better engine inspection.  

[Duke McDukiedook]

Yep, check your cam chain tension and your oil screen and pump while you are in there.
You'll want to change the pan gasket and drain plug crush washer also.

I would change your oil again after only a few minutes of running (under load) if the oil is that dirty after your first change- no use in running cruddy oil in there any longer than you have to.

[RamblinMan]

Don`t forget to change the filter each time you change the oil , price of filters is cheap compared to engines .

[raymond10078]

What is interesting (to me anyway), is that I finally obtained an Owner's Manual, and dropping the pan to clean the pump inlet screen is a recommended periodic maintenenance item (every 12 months or 6,000 miles)!  I didn't expect that!

If I had known that, I wouldn't have asked the question . . . .

[stinkfinger]

Curious to know what the pan and filter looks like in yours.
I need to do mine(it sat for an extended time also)
but havnt had time.......excuses/excuses

Tony

[jweeks]

Anywhere there's a filter screen, debris builds up over time. Don't forget the gas tank has a crude screen at the outlet. Hondamatics in storage tend to rust up the gas tank. Rust flakes can/do cover the screen that allows gas into the carbs. You may seem to have a lean condition that really is restricted fuel flow. Sam G. found that out the hard way a year ago. Gas also turns to a gel or solid after enough storage time.
     Oil won't do that. Condensation in the oil pan is all that you usually get with storage. If there's gas in the oil, that's another problem. If the screen on the oil intake is covered, it's usually from silicone from rebuilds and pieces of gaskets. If you're finding metal flakes in the oil intake screen, you've got other problems to check for. If there's metal in the oil, a magnetic drain plug is the best way to find it. How much you find helps to determine if there's a motor problem. Just my 2 cents.
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