gs1000 wiped out bearing surface

[nitro3custom]

I am currently running with a wiped out bearing journal in the head. surprisingly the bike has run like this since I got it. And it runs real good. Has anybody ever machined the head out and put bearings in Like in a kz1000? I never did understand why they spin in the aluminum anyway.

[Nessism]

They run the cams on the aluminum because it works and is cheap; as long as decent oil is used, and the engine isn't overheated to death, the head lasts the life of the engine. Regarding machining the head, sounds like a good project but I have no assistance to offer. A new/used head off ebay typically sells for about $150 or less so you might want to just go this way to save time and money unless you are a machinist by trade, in which case please post lots of photos of this project.

[BassCliff]

Greetings and Salutations!!

Hi Mr. nitro3custom,

I can't really help you with your bearing either, but I'll share some GS lovin'.

I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", the Carb Rebuild Series, and the Stator Papers. Now let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

[chef1366]

Is the lower bearing surface that is part of the head toast?

[nitro3custom]

Thank you for the welcome. I've actually been a member for a long time but just mostly just read. My bike is a 1981gs1000l and I'll post a pick of it as soon as I can. I have another head from a 78, but I am considering the bearing route. That's just in a planning stage though. I can do the machining but have friends who could do it for me too.


Yes the head is toast and I think the cap might have been too. I've been running it that way for about since i got it just because I haven't gotten around to doing anything about it. and i am still amazed at how the bike runs knowing that there's a problem

[duaneage]

i have a 8 valve head from a GS1000G that is in decent shape for sale. PM me for details

[nitro3custom]

No luck finding bearings yet. And I have a 78 head that I can use but I'm now finding out I might need to modify or make adaptor plates for the 81 carbs. Luckly it's winter and i've got time. i did send my cams to web through dynoman so that's underway. Just going with the 118 grind, this bikes pretty fast for street bike as it is.

[Big T]

You'll spend more time and head aches and money on adapting the small port 78 head than just swapping your damaged head for a proper one

Not hard to find one, just check post #6

[blowerbike]

simple fix..
install the larger boots on the early head...
mark the port size difference/remove boots and funnel the port to match the larger boots.
both heads have the same size valves and combustion chambers.
or find a nice CV head thats priced right.
the bearing idea was bad to start with when a replacement head would be much less labor intense.
even kawi quit using the bearings a million years ago...no benefits and they saved a ton of money.

[7981GS]

simple fix..
install the larger boots on the early head...
mark the port size difference/remove boots and funnel the port to match the larger boots.
both heads have the same size valves and combustion chambers.
or find a nice CV head thats priced right.
the bearing idea was bad to start with when a replacement head would be much less labor intense.
even kawi quit using the bearings a million years ago...no benefits and they saved a ton of money.

Have you actually done this?
How much material did you have to add to the bolt bosses so that you could drill/tap new threads for the manifolds to bolt up? (after filling the existing threads)
Or did you elongate the ear holes in the manifolds to line up with the smaller port head threaded bosses?
How did you keep the larger O-rings sealed now that they are hanging over the edge of the port mounting flange?
Blending the post size difference would not take too much. But how did you mount the manifolds/seals?

Daniel

[blowerbike]

Have you actually done this?
How much material did you have to add to the bolt bosses so that you could drill/tap new threads for the manifolds to bolt up? (after filling the existing threads)
Or did you elongate the ear holes in the manifolds to line up with the smaller port head threaded bosses?
How did you keep the larger O-rings sealed now that they are hanging over the edge of the port mounting flange?
Blending the post size difference would not take too much. But how did you mount the manifolds/seals?

Daniel

no no and no...
no welding or drilling/tapping ect...
slot your boot mounting holes or purchase a set of "big boots" from schnitz racing/APE or who ever you choose.
and yes i have done a few of these in the past 20 plus years.
FYI
i have installed 32/34/36mm vacuum/jet kitted carbs on small port heads on 77-79 GS's and 73-80 ish KZ/Z1's.
i only give advice from my past experiences..no guessing or 5th hand bad information from billy bob's sister's cousins brothers friend's dad ect../..ect..
this is a simple procedure.

[BlackStar]

Cary Aspy over at scnitz racing did mine while he was doing the valve job on my cyl. head. Matched to ports to the Kawi intake boots so that RS34's would mate up. IIRC there was less than 1/8 step that needed to be removed. No hole relocation work needed for these boots. There is plenty of material.
Unfortunately Cary is no longer with us.
To answer a few questions. I did elongate the manifold holes a little, not much required.
These boots don't used O-rings, the seal is integral, a little Yama-Bond and your good to go.

[7981GS]

With the aid of some old parts that I have laying around,
I took some pictures to graphically show what I am talking about.
'79 GS1000 head and '81 intake manifolds.

Centered on intake port:


O-ring hanging on the edge:




Port and manifold:


So, you would NOT have a problem with the seal hanging on the edge?

I can see an intake manifold that is designed to be used in this application but, modifying a stock one and relying on this to seal?

Daniel

[Nessism]

So, you would NOT have a problem with the seal hanging on the edge?

I can see an intake manifold that is designed to be used in this application but, modifying a stock one and relying on this to seal?

Daniel

Daniel,

You highlight why people use Kawasaki intake boots when performing such a mod. The KZ boots need the mounting holes slotted before they will bolt up. Z1 Enterprises sells the boots for $55/4 boots - cheaper than GS boots. http://z1enterprises.com/detail.aspx?ID=314

[7981GS]

But why would anyone go to the expense/trouble for small port flow?
I just got the larger port head and used the 34CV's on the 850.
Jetted for the 4-into-1 header.

Daniel