Topic: CB750F2: Time for a Head Job!

[Loudpipe]

Where can I find a manual and the parts necessary to rebuild the top end of my '78 750F2? 20,000 miles and it's smoking on startup and at idle.  Sounds like a winter project.  If I can source all the parts from the same place it'd be great, but if not it's OK.

Thanks.

[scondon]

  Since it is most likely the valves/guides, Dynoman.net  or Mrieck(forum member) are the two that spring to mind with F2 specific parts/work and knowledge. Not sure if Honda supplies pistons/rings for this engine anymore so you might want to check with them or Dynoman for options.

   A Honda Shop Manual should cover the basics for a engine rebuild and can be found on eBay or free download on the internet(this site?). A '78 specific Honda manual is also available, but harder to find.

[Loudpipe]

What are parts are likely in need of replacing besides just the guides and valves?  The compression is good, and the engine hasn't been making any wierd noises so I really think the bottom end is in good shape.  Also, is there a place around that sells carb rebuild kits and the tubing that runs between?  Number 4 leaks like a sieve and all the carbs could probably use a thorough cleaning.

[rbmgf7]

i have the dealer shop manual and i'ts not too in depth about replacing valve guides for the F2. It pretty much says to bang them out and bang them back in. I can scan the page and send them to you if you'd like.

there's a previous post about someone recently changing their guides. do a search and read up on what the guys said to do. I'm sure the Honda manual is one way doing it but these other guys have better ways.

[bryanj]

78 with 20,000 hmmmm

4 x exhaust valve guides
1 x COMPLETE top end set
Maybe camchain with link
carefully inspect cam chain tensioner rollers and cushion
1 x day of your work
1/2 day "farmed out" work (v/v guide fitting + seat cutting etc)

I have the UK Honda dealer shop manual scanned to cd if you want a copy for cost of postage + a beer

[Sam Green Racing]

Take the easy option and send it to Mike Reick.

Sam.

[Terry in Australia]

Be careful and don't fall into Bryan's cunning trap, English beer is very expensive!

[jtb]

Be careful and don't fall into Bryan's cunning trap, English beer is very expensive!

But it's warm.

[Lumbee]

...loudpipe, go ahead and do the tear down [top end] and wait and see what you find.  if the valve guides are that bad, you will be able to feel the play between the valve and valve guide.  i bet u'll find they are ok...new valve guide seals will stop any leak down into the comb. chamber that would be causing any smoking...

[Loudpipe]

Cool. Thanks everyone.  How about those carb kits?

[mikedialect]

78 with 20,000 hmmmm

4 x exhaust valve guides
1 x COMPLETE top end set
Maybe camchain with link
carefully inspect cam chain tensioner rollers and cushion
1 x day of your work
1/2 day "farmed out" work (v/v guide fitting + seat cutting etc)

I have the UK Honda dealer shop manual scanned to cd if you want a copy for cost of postage + a beer

what would it typically cost to have the guides fitted and cut? My f2 has similar issues- but I won't be getting to it until I finish the 4 cb350's in front of her- I just want to know what that will set me back.

[Lumbee]

..if its just leaky bowls you can get bowl gaskets here pretty cheap...

http://www.crc2onlinecatalog.com/bowl_gaskets.htm

...if you want the whole kit check out http://stores.ebay.com/Sirius-Consolidated-Inc

[Bodain]

what would it typically cost to have the guides fitted and cut? My f2 has similar issues- but I won't be getting to it until I finish the 4 cb350's in front of her- I just want to know what that will set me back.
[/quote]

Well I just did my 78 Head.....

$70.00 for 8 brass valve guides... ( I've only used 4 for the exhaust the intake was fine)
$32.00 for 8 valve guide seals

I removed the intake valves and lapped them. They are fine.
Removed old exhaust guides and installed the new ones.
Then it was $225.00 for the valve job on the 4 exhaust valve.

So I've got $327.00 in my 78 F head. I'll start putting it back together tomorrow night. Should be running Saturday...
If the thing still smokes I'm pulling the engine and selling is as scrap.. I'm not putting another dime in this engine.

[mikedialect]

what would it typically cost to have the guides fitted and cut? My f2 has similar issues- but I won't be getting to it until I finish the 4 cb350's in front of her- I just want to know what that will set me back.

Well I just did my 78 Head.....

$70.00 for 8 brass valve guides... ( I've only used 4 for the exhaust the intake was fine)
$32.00 for 8 valve guide seals

I removed the intake valves and lapped them. They are fine.
Removed old exhaust guides and installed the new ones.
Then it was $225.00 for the valve job on the 4 exhaust valve.

So I've got $327.00 in my 78 F head. I'll start putting it back together tomorrow night. Should be running Saturday...
If the thing still smokes I'm pulling the engine and selling is as scrap.. I'm not putting another dime in this engine.
[/quote]

don't you mean ship it to me so I can swap it with a k head?

thanks for the info!