Topic: First post - need advice on 1978 CB750F I am looking to buy

[daewon774]

What's up everyone?  This is my first post.  I've been lurking around reading and catching up on some research for the 750s.  I'm trying to find a project bike for the upcoming winter.  Hopefully a decent 750 that I can cafe out.  I found an ad locally on craigslist for a 78' CB750F.  I was wondering if there were any main concerns other than the valve issues that come up from time to time? 

Also, I was sent this through the email from the owner "As I mentioned in the ad, the last time I ran it it developed an oil leak which dripped onto the pipes.  I wasn't able to locate it.  It was after an oil change and I wonder if I didn't seat the old style filter cartridge quite right."  I just wanted to see what everyone thought the culprit could possibly be before I go see the bike?  Gaskets?

Thanks in advance, hopefully I'll be a CB owner soon. 

[BobbyR]

He may have stripped the bolt on the filter cover or did not place the o ring in properly if at all. Take a look at the valve covers for signs of a leak.

[MRieck]

 I have seen cracked oil filter covers especially around the bolt hole

[754]

might be tach seal..

[daewon774]

thanks for the posts everyone.  I'll check the valve cover and see where the leak is coming from.  Any other advice when I look/ride the bike?

[bryanj]

Any blue smoke walk away unless you are going to send the head to mike, search F2valve guides!!

[BVCB650]

Any blue smoke on start up isn't too scary if it goes away in time. No biggy to rebuild heads. I had a valve stem tip that sheared off so that I couldn't set that valve. Got a new/used fleebay head and slapped it on there. Runs like a scalded dog now.

[bryanj]

That works for all but the F2/3 which are notorious for bad guides

[BVCB650]

That works for all but the F2/3 which are notorious for bad guides

So are the 650's. Bad guides let the valves tip. There was a recall back in the day. Not a huge repair thing. Just a little time and money.

[kvallelunga]

As an owner of a '78 F, I say go for it. These old gals' are getting scarce. If it runs it won't cost much to make it yours. If it doesn't you should be able to get it cheap enough to make it worthwhile to repair. Even if you bought a newer, say $2000 dollar bike, you still probably need tires, battery, brakes, tune-up, etc, getting you into some big money quick. Even if it is the valve cover leaking it's only time to fix it, the cost of the gasket is negligible.

[MRieck]

Any blue smoke on start up isn't too scary if it goes away in time. No biggy to rebuild heads. I had a valve stem tip that sheared off so that I couldn't set that valve. Got a new/used fleebay head and slapped it on there. Runs like a scalded dog now.

Compared to what? Personally every one on these F2 heads I've ever seen had a problem. Guides, blown out valve faces, bad tips and out of round stems. I guess I brand new head would be OK....for a short while. I have many of these heads too.

[BVCB650]

Any blue smoke on start up isn't too scary if it goes away in time. No biggy to rebuild heads. I had a valve stem tip that sheared off so that I couldn't set that valve. Got a new/used fleebay head and slapped it on there. Runs like a scalded dog now.

Compared to what? Personally every one on these F2 heads I've ever seen had a problem. Guides, blown out valve faces, bad tips and out of round stems. I guess I brand new head would be OK....for a short while. I have many of these heads too.

Compared to an unscalded dog.  ???The valve guides were recalled back in the day. Maybe they got it right. Maybe not. At any rate, the head on there now is a 6000 mile head and thats 19K less than before.

[jtb]

Compared to what? Personally every one on these F2 heads I've ever seen had a problem. Guides, blown out valve faces, bad tips and out of round stems. I guess I brand new head would be OK....for a short while. I have many of these heads too.

Surely you're not including my head in that mess, Mike.

[750Caferider]

I've got a 78 750 F and am learning that the 77/78 750F's are a little harder to find parts for but not impossible.  There are pros and cons to each year or K model.  The biggest concerns I would have is what is my budget, good local machine shop, ability and time to source parts and weather you are going to do the all the work yourself(engine rebuild if neccesary)?  Good luck and hope to see your bike on here!

Cheers,

Anders