Honda-SOHC

SOHC.co.uk Forums => CB750 => Topic started by: Robbo on May 24, 2012, 01:15:52 PM

Title: F2 valves
Post by: Robbo on May 24, 2012, 01:15:52 PM
My F2 is burning a bit of oil, it is leaking a little so I was going to take the engine out to check it out.
In a previous post an old article said to replace valves, springs, retainers and everything every time you have an f2 apart as they are more likely to cause severe engine damage when they fail.

After having a look around it seems like this is going to cost hundreds of pounds, $750 from dynoman and waaaay more from csmnl.
Has anyone done this, is it necessary? Is there a cheaper way to do it without compromising the engine?

Title: Re: F2 valves
Post by: Tomb on May 24, 2012, 04:56:41 PM
yep, keep topping up the oil. :o
Title: Re: F2 valves
Post by: Seamus on May 24, 2012, 04:59:48 PM
I would measure all the bits and only replace stuff that was out of spec.

When does it smoke, under load = rings/bores etc
on overrun, then valves etc.

Hope that helps

Title: Re: F2 valves
Post by: Robbo on May 24, 2012, 09:47:14 PM
Gunna test the compression this weekend, this should give me an indication if either the valves are not seating right or if the piston/rings are knackered.

In this weather I just want to be riding, not wrenching.
Title: Re: F2 valves
Post by: Bryanj on May 25, 2012, 07:22:23 AM
When they smoked under warantee it was just replace valve guides(exhaust only NORMALY) stem seals and gaskets/"O" rings all they rest was usually OK
Title: Re: F2 valves
Post by: Waggles on May 28, 2012, 10:34:45 AM
Think it was me that posted that old article. As I said at the time I can't remember where I found it and it could easily be quite old. Automatic replacement was probably good advice when parts were cheaper! I think its best to take it as a warning of a possible weak spot and check carefully as Seamus says.