TOPIC:

Thinking about replacing the valve guides in my KZ750 head while it is off and was wondering if it a fairly simple task to do? is it pretty much punch them out with a drift and then smack some new ones in with a correct sized socket or hollow bar?

they should be pressed in. then they have to be honed to fit the valves

btchalice wrote:

they should be pressed in. then they have to be honed to fit the valves

What he saidB)

Jay

On top of honing the valves, I believe the valve seats should be recut as well... the new seats will position the valves slightly differently on the seats... this issue is called concentricity. The seats should be freshened (valve job), new guides reamed with a 7mm reamer, valve lengths adjusted (valve stems ground) and new seals installed. Before getting to all this work, I would remove the head and wiggle the valves in the old seats to see if there is any rocking. If they don't rock, that is a lot of money and effort to spend fixing what don't need fixed.

The reason i ask is that i have an unknown mileage donor bike. The original bike i am rebuilding looks like it has had detonation in one of the cylinders and stuffed one of the exhasut valves ( externally looking it is pitted) and i have a donor bike that i havent taken the head off yet.

I am planning on buying a set of valve springs from APE
(VS-900K) and a set of adjustable cam gears to suit if they make them. to save on postage to Australia (top shit country) i was thinking of getting a set of valve guides from APE while i was buying some other stuff to save on postage. i am doing An 810 kit on the bike if the pistons ever arrive from Pro-flo. (first set were lost by usps, guy at pro flo has been realy helpful)

I will be pulling the head on the donor bike this weekend. Have to make an adapter for my valve spring compressor for the bike head.

you guys have any good sites for DIY porting?

sorry for the long post. 1/2 a bottle of jim beam will do that to ya

11:30 pm signing out

Why do you want to spend the $$ for a pair of adjustable cam sprockets? Especially considering the shipping cost.

All you need to do is use a rat tail fle or a Dremel (or similar) and elongate the bolt holes a little (.020"-.030", .5mm-.75mm), not difficult at all.

since the valve springs will be $40 AUD cheaper all up including shipping from APE to get to me than through my local kawa shop i was thinking about ordering some other stuff at the same time. as i will be looking at getting my cams reground and welded in the future by ivan tighe engineering. i thought adjustable cam sprockets would be a wise investment. but if i only need to enlage them by a small ammount as i have a dremel and a die grinder it may not be worth it.