Swapping Head GS850

[Guest]

The warm weather is upon us in the Hoosier state. It’s time to get the bike out. A forum member last year holed me up with a good GS850 head to swap mine that had a mangled exhaust thread. Some may remember my tribulations with that. My question is, when putting the new to mean head on will I need to have the valve seats recut and my current valves reground to match? Also is there any tip or trick for keep the cam chain in place so it doesn’t drop?

[Nessism]

A proper fix involves pulling both the head and cylinder, inspecting all the parts and cleaning/fixing what needs fixing, and then reassembling with new OEM gaskets. If the valves need cutting, cut them. If not, lapping and replacing the valve stem seals is good enough. Same for the piston rings. Regarding the cam chain, I just drop it down to get it out of the way. A magnet stick will allow fast retrieval when the time comes.

[Kodak]

Ahh I know the right thing to do is as you described. Just want to get back on the bike ASAP! This is an ignorant question, how would I know if I need to recut the valve seats?

[Burque73]

If that's the head that came from my assortment of parts, I never would have just slapped it on and ran it. It came to me from an ebay seller and had dirt in the tachometer drive gear. In fact, didn't I send a bunch of gaskets and valve seals too? I have no idea of the condition of the seats or seals and if there's dirt down inside the head. Man, be careful and clean it/ inspect everything.

[Nessism]

You can try propping up the head with ports to the top and then filling them with diesel fuel or mineral spirits (paint thinner). If there is leakage out the combustion chamber side you need to pull the valves to see why. Typically the exhaust valves are worse than the intakes because many idiot owners think valve adjustment is optional and wind up burning the valves. Needless to say this is a halfassed way to assess the condition of the parts but you be the judge what you want to do.

[rapidray]

Do you want to do it RIGHT, or do you want to do it AGAIN?????
Ray.

[Kodak]

If that's the head that came from my assortment of parts, I never would have just slapped it on and ran it. It came to me from an ebay seller and had dirt in the tachometer drive gear. In fact, didn't I send a bunch of gaskets and valve seals too? I have no idea of the condition of the seats or seals and if there's dirt down inside the head. Man, be careful and clean it/ inspect everything.

Hey Roger,

Yes this is the Head you sent me. Do not worry I haven’t even started cleaning the head up and inspecting it for the swap. I have the Suzuki manual and will be following it for this job. I was only asking hypotheticals. Just gathering info before I start.

[Kodak]

You can try propping up the head with ports to the top and then filling them with diesel fuel or mineral spirits (paint thinner). If there is leakage out the combustion chamber side you need to pull the valves to see why. Typically the exhaust valves are worse than the intakes because many idiot owners think valve adjustment is optional and wind up burning the valves. Needless to say this is a halfassed way to assess the condition of the parts but you be the judge what you want to do.

I assume the Suzuki manual describes the proper way so I’ll be sure to check that as well. I certainly don’t want to give the impression I’m wanting to cut corners I’m just curious about the ways to go about it

[Kodak]

Do you want to do it RIGHT, or do you want to do it AGAIN?????
Ray.

Both! I love turning a wrench!

[bwringer]

It depends on what you're starting with.

At minimum, you'll want to replace the valve stem seals, so the valves have to come out, and then you can take a good close look at the condition of the valves and seats.

If you're anywhere within some reasonable ride distance from Indy, I'd be happy to take a look.

[Steve]

If you're anywhere within some reasonable ride distance from Indy, I'd be happy to take a look.

He's about 150 miles due north.

Sounds like a nice ride, to me.

I stopped and visited him last year on my way home from Wisconsin.

.