BassCliff GS850GT Top End Refresh

[BassCliff]

...Disassembly continued

...Disassembly continued

Hi,

I removed the breather (still with its Real Gasket), the cam end caps, and the valve cover.

The OEM valve cover gasket came off whole. I had installed it after coating it with grease and it came off in one piece. I actually have a couple of spares but I try to re-use this one since it looks so good.

Before I started on the cams I thought I'd put #1 to TDC.

For grins and giggles, after removing the cam idler, I counted the links between the numbers and found exactly 19 (20 if you count the "zero" pin) between the '3' mark and the '2' mark.

(Do the marks above mean that the #1 piston is at the top of the compression stroke or exhaust stroke?)

And off comes the cam idler.

Be sure none of the bits are dropped into the engine. These dowels did not come off with the rest of the unit because I didn't grab the whole assembly.

The whole cam idler assembly.

Next I removed the tach send gear assembly. First the cable.

Then the lock pin.

Lots more pictures. Stay tuned.

Thank you for your indulgence,

BassCliff

 

[BassCliff]

...Disassembly continued.

...Disassembly continued.

Hi,

Then the cam gear send unit itself took a little persuasion to come out.

And it comes free with a little wiggling and jiggling. The gear itself might slip out of the seal housing but that's no big deal.

Then I used a 10R vice grip pliers to hold the cams in place.

Then you must loosen and remove the bolts on the bearing caps in a cross pattern, one turn at a time, in order to relieve the valve spring pressure evenly.

Only 2 of the 4 bolts have dowels on the bearing caps. One of these I could not persuade to come out at all. But I don't think that will be an issue.

After removing both bearing caps, the vice grip pliers are loosened and the cam can be removed.

Before removing the other cam shaft, be sure to secure the cam chain so that it doesn't fall down into the engine. That might be pretty inconvenient.

Let's not forget that one little bolt on the front of the head.

Then I removed the smaller bolts right next to the #1 and #4 spark plugs.

Now we're ready to removed the 12 main head nuts. Start with the outside nuts and work your way toward the middle in a cross pattern. The order is in the manual. But I will spell it out in the tutorial. ;-)

Still have more pictures. This is going to make a heck of a tutorial. ;-)


Thank you for your indulgence,

BassCliff

 

[BassCliff]

...Disassembly continued.

...Disassembly continued.

Hi,

As the head comes off be sure to fish the cam chain through and secure it again. Don't let it get away from you.

And this is just what we expected, #1 and #4 up with #2 and #3 down.

The head gasket came off easily enough. I wish I could say the same thing for the base gasket. (At least the base gasket stayed stuck to the jugs.)

Seems I had one of those dowels in the cylinders come out and one did not want to. Hopefully that won't be an issue either.

I'll be disassembling the head to replace the valve seals and check the springs. Maybe I'll even lap the valves.

I should probably clean these up a bit.

Now it's time to get the jugs out.

Here's a gratuitous shot of Jessie's jugs.

And this is how I left Jessie, with shop towels tucked into vulnerable areas so that no foreign debris or critters could fall in.

Next comes honing the cylinders, replacing valve seals, new rings, new gaskets, new O-rings in the carbs, etc. This old girl should be feeling pretty good after all this work on her top end.


Thank you for your indulgence,

BassCliff

 

[Guest]

You go Cliff!!

 

[JEEPRUSTY]

This is a nicely done thread.
More pics more more more.

 

[Guest]

Looking great Cliff. I tried everything on my base gasket but in the end it was gasket remover followed by a razor blade, and it was mostly razor blade that got it off, just watch that aluminum. I'll be watching to see how you put the pistons back in with the new rings, don't be like me and try to do it by yourself, get the tool or get a friend. She's going to be even more of a joy to ride this season Cliff, you'll be all grins!

 

[BassCliff]

Hi,

Aw, thanks guys.

I know a lot of you have done this kind of thing several, if not dozens or hundreds of times. But I thought I'd take lots of pictures to show everyone else that this stuff is not nearly as scary as it seems.

I'm actually reading the manual as I go but I'm sure I'll still have a few questions.


Thank you for your indulgence,

BassCliff

 

[Badooka]

BC,
Have a friend help you put those jugs back in- I did it by myself and it was colorful to say the least!
Your welcome to my flex hone- Just send her back when your done!

 

[Dogma]

Looking great Cliff. I tried everything on my base gasket but in the end it was gasket remover followed by a razor blade, and it was mostly razor blade that got it off, just watch that aluminum. I'll be watching to see how you put the pistons back in with the new rings, don't be like me and try to do it by yourself, get the tool or get a friend. She's going to be even more of a joy to ride this season Cliff, you'll be all grins!

Gasket remover in a can is useless. At least the stuff I found. It was meant for softening silicone adhesive, so it had nothing to do for a GS head or base gasket. Razor blades are the most dangerous thing I've found. At best, you can remove a lot of thickness from a stuck gasket by scraping with the blade almost 90? to the surface. I never got one to lift a gasket that was really stuck. Anything a razor would lift could have been pried up with a plastic scraper.

On my 1000, I used a combination of brass wire wheel in the cordless drill (very slowly) to rough up and remove gasket material, with green Roloc wheel in the regular HF drill motor or die grinder (speed!) and stainless wire wheel in the Dremel to finish down to bare aluminum.

The Dremel wire wheels don't last long if you use more than about the weight of the tool, so be ready for flying wires. The carbon steel wire wheels for the Dremel mark the aluminum too easily, and the brass is so soft it plates itself onto the gasket.

I'm not persuaded by GM's warning about the Roloc wheels. They blamed some failures on these. Just don't let the dust into the engine, and clean everything before reassembly (duh).

The brass wire wheel in the cordless drill is the one I hesitate to recommend. Don't hold the wheel perpendicular to the aluminum, or it will definitely leave gouge marks when it breaks through the old base gasket. Still, I found it safer and more effective than the razor. One might prefer a brass brush. Be patient and use nothing but the Roloc and Dremel with stainless in any area that has to seal something (about 5mm around the cylinders, and around the rear stud oil passages).

A stainless cup wheel in the drill motor does a nice job on the piston faces and combustion chambers. Some of the carbon on the valves I pried off with a screwdriver.

Patience is very much required. I spent maybe 10 hours getting everything cleaned up on the 1000. I don't remember my 850 taking quite so long. I hope yours goes better, Cliff.

 

[Badooka]

Gasket remover in a can is useless. At least the stuff I found. It was meant for softening silicone adhesive, so it had nothing to do for a GS head or base gasket. Razor blades are the most dangerous thing I've found. At best, you can remove a lot of thickness from a stuck gasket by scraping with the blade almost 90? to the surface. I never got one to lift a gasket that was really stuck. Anything a razor would lift could have been pried up with a plastic scraper.

On my 1000, I used a combination of brass wire wheel in the cordless drill (very slowly) to rough up and remove gasket material, with green Roloc wheel in the regular HF drill motor or die grinder (speed!) and stainless wire wheel in the Dremel to finish down to bare aluminum.

The Dremel wire wheels don't last long if you use more than about the weight of the tool, so be ready for flying wires. The carbon steel wire wheels for the Dremel mark the aluminum too easily, and the brass is so soft it plates itself onto the gasket.

I'm not persuaded by GM's warning about the Roloc wheels. They blamed some failures on these. Just don't let the dust into the engine, and clean everything before reassembly (duh).

The brass wire wheel in the cordless drill is the one I hesitate to recommend. Don't hold the wheel perpendicular to the aluminum, or it will definitely leave gouge marks when it breaks through the old base gasket. Still, I found it safer and more effective than the razor. One might prefer a brass brush. Be patient and use nothing but the Roloc and Dremel with stainless in any area that has to seal something (about 5mm around the cylinders, and around the rear stud oil passages).

A stainless cup wheel in the drill motor does a nice job on the piston faces and combustion chambers. Some of the carbon on the valves I pried off with a screwdriver.

Patience is very much required. I spent maybe 10 hours getting everything cleaned up on the 1000. I don't remember my 850 taking quite so long. I hope yours goes better, Cliff.

I agree 100%- I spent close to two weeks on those gaskets-I soften with brake cleaner and let the fun begin.

 

[Guest]

When I've used gasket remover it was pretty useless in the fact that it wouldn't take anymore than the very top surface off, so I'd spray it let it sit and then scrap it off with the blade. When I get down to the final layer near the head it's like being a surgeon. I've done two that way with no issues but I do agree you have to be very careful and very patient. I stopped taking count of how long it took me, long enough that's for sure. I tried the wire wheel route but had no success, maybe next time I'll try your suggestions.

 

[GSXR7ED]

Good tutorial BassCliff. Thanks for sharing.


Ed

 

[Steve]

I'm actually reading the manual as I go but I'm sure I'll still have a few questions.

Don't forget to check BassCliff's "little website", he probably has something on there for you. :-\\\


The best gasket scraper I have is an old 1/2" wood chisel. I keep it sharp, so it does not take much effort to get under the gasket and lift it up.
The key is to keep the tool flat to the work so there is no chance of gouging it.

.

 

[BassCliff]

Hi Steve,

Don't forget to check BassCliff's "little website", he probably has something on there for you. :-\\\

The best gasket scraper I have is an old 1/2" wood chisel. I keep it sharp, so it does not take much effort to get under the gasket and lift it up.
The key is to keep the tool flat to the work so there is no chance of gouging it.

Ha! Thanks, Steve. I check out that guy's website and see if it's any good.

Thanks to everyone for all the gasket removal advice. It sounds like that's going to be the toughest, most time consuming part of this project. I really appreciate all your insight and experience.


Thank you for your indulgence,

BassCliff

 

[alke46]

Good tutorial BassCliff. Thanks for sharing.


Ed

+1 on that. Thanks very much for sharing. Good job so far.

 

[Big T]

Cliff

I recommend a thorough exam of the cam chain guides and possible replacement

They are 30 years old, you know

 

[jdknicks]

Basscliff,

Where did you get the hex screws for the circular cylinder head side covers? I just finished adjusting the valves on my 750 and had one heck of a time getting those off. I actually broke two bits on one screw.

Sorry to hijack and thanks!

 

[rustybronco]

(Do the marks above mean that the #1 piston is at the top of the compression stroke or exhaust stroke?)


Thank you for your indulgence,

BassCliff

Compression...

Dowels won't be an issue.

 

[Johno]

Watching this thread with keen interest! Thanks for posting.
What material are the oil catch pads made from Cliff?

Thanks Cliff for the great photos and detailed description.

I'm expecting to go down a similar track to replace carb inlet rubbers and O rings. This will be my reference.

 

[oldgsfan]

This is great, BC - I'm actually doing the exact same thing on my 850 but am a couple of steps behind you.

I'm really glad you're posting these pics!