GS850 Rebuild or Oh my god what have I done?

[koolaid_kid]

That stator is on its way out, btw. Check the spare motor and see if it looks better.

[loud et]

New springs....good one.

[Daffid]

I pulled the cover off spare motor #1 today and was very pleased with the state of things! Looked much better, no broken bolts or stripped threads.

Some pics:





The down side is it looks like water got into the cylinders and there's rust. No idea how bad yet. I think I'm going to pull it out of the frame and tear it down further. Yay!..../sigh.

Hey Koolaid Kid, not disagreeing with you, but what are you seeing that gives you that impression? Educate my untrained eyes!

The stator on spare#1 looks like crud. Are stators interchangeable from all the different model years? I have a spare#2 that is a '79. If it looks ok could I use it? I'm thinking I'm probably better off just forking out for a new stator altogether, but I like to know my options.

Here's a pic of the stator from spare#1:

[Steve]

Not quite sure what's going on here, it appears to be aluminum from the head, due to over-torquing the bolt.

This one, though, appears to be a Heli-Coil that is unwrapping. Try putting a standard M6 bolt in there. If the hole is too large, it probably just needs a new Heli-Coil.

The stator on spare#1 looks like crud. Are stators interchangeable from all the different model years? I have a spare#2 that is a '79. If it looks ok could I use it? I'm thinking I'm probably better off just forking out for a new stator altogether, but I like to know my options.

'79 and older bikes have 12-pole stators. '80 and newer bikes have 18-pole stators. They are not interchangable, unless you also change the rotor on the crank.

Here's a pic of the stator from spare#1:

I'm not sure what Koolaid_Kid saw in your first stator picture, I rather liked it. Certainly a LOT better than this one.

.

[Daffid]

Thanks Steve. If I'd have had to guess who would know that I'd have put my money on you. :-)

I agree that the silver stuff left on the threads looks like the result of someone over torquing. If the springy thing is what's left of a heliacoil... Well, couple that with the two sheared bolts and everything else and I'm pretty sure I don't want to mess with that head any longer. I've been doing my homework the last couple of days and I'll be diving into pulling both heads this week after work.

Stuff is about to get real up in here.

[Good Times]

Go for it Daffid. I think that is a good option. Since you have another head it will save you a lot of head ache.

[Daffid]

Hold the head-ache

What a weekend! I finally finished some other projects around the garage and got the chance to work on the bike today! I dropped the exhaust off the spare motor, pulled the head... I'm not often at a loss for words, but I'm not sure what to say. Carbon... If I were to go looking for the raw materials to start a new carbon-based life form, this engine block is all the farther I would have had to look for the carbon. All except for cylinder 4 that is. Here there be rust! Lets take a look:



That's 1 on top and 2 on bottom.



That's 3 on bottom and 4 on top.

This is the bottom of the head, 1 on the right:



Drumroll please!:



That's number 4 on the left. Now in the process of removing the head two of the exhaust bolts broke. I thought I was doing well at getting them out, about a quarter turn, a little PB Blaster, quarter turn back in, let it sit, wash-rinse-repeat. It worked on all the rest of them, and most of them were pretty well seized up, but I didn't luck out on these two. I have enough sticking out to grab a hold of, but I'll have to be careful getting them the rest of the way out. If I can get those two out, I'll not have a bad set of threads on the whole thing.

On the other hand... This thing has seen better days. My smoker, well broken in piece of equipment that it is, still doesn't have the buildup that this thing has! Oi... But what really worried me was the rust. I went to work on it with simple green and a brass brush. That didn't get me terribly far, but it got the rust away pretty well. I think the carbon buildup actually protected the head and the valves from some of the rust. Its not as pitted or scarred as I thought it would be. After I got the rust out there was still a good deal of carbon buildup. I attacked that with the brass brush and some carb/choke cleaner. The result:



Now I just have to get the others cleaned up and figure out if the valves are good or if I'm going to have to drop a boat load on new valves.

[Daffid]

I haven't pulled the head off the original motor yet so I don't know how the cylinder walls look in there, but I'm willing to bet that they look quite a bit better. I'm not liking the idea of using the block from the parts motor if I don't have to.

[Good Times]

Yeeeesh....... nasty all up in there. Good work today though.

[Daffid]

Thanks GT!

This is #3 after I tore into it last night:



So I'm a little concerned about the valves. I still haven't figured out how I'm going to depress them to inspect the seating, but beyond that, there appears to be some kind of coating on them that is coming off? Do they have some kind of special protective layer?

Here's what I'm seeing close up:



What the heck is that?

[Good Times]

I'm no expert on valves, but I would say that's carbon build up on the valves. When I have seen clean valves they don't have anything that looks like that on them.

[7981GS]

Soaking in carb dip might help getting that off. I have never tried, yet.
I usually sand-blast them. Still tough.

Eric

[Steve]

Don't worry about what you are seeing on the valves. Just knock off the loose stuff and call it a day.

.

[Daffid]

Ok. That I can do. How careful do I have to be of the rest of the combustion chamber part of the head? Obviously the valves are a different, hardened material, and the rest of the head is just aluminum. If I nick or scratch it just the slightest bit, it should be fine right? I'm trying to be careful not to damage anything either way, but I just want to make sure that if I have a little oops here or there I'm not jeopardizing my ability to use the head.

Also, getting off God-know's-how-old gasket goo is a real pain...Thinking about trying Girlfriend's magic eraser on it. I don't think that'll mar the aluminum too much. I've got a brand new can of Berryman carb dip that I suppose I could pour into a container and immerse the head in. That stuff doesn't eat Rubbermade plastic tubs, does it?

Any neat ideas on how to push out the valves so I can check the seat/seal on each? Or for that matter, what to search in the forum other than 'check valves' so I can narrow down the results?

[Daffid]

Hey Eric, what do you usually sand blast them with? Soda? The only thing keeping me from playing with my sand blast cabinet is the 220 wiring needed for my compressor and a decent in-line dryer. This just might be my motivation to get that done asap...