GTR questions

[poppaweelee]

I just bought a '67 GTR with 6300 miles on it. It is all original including the seat. It had been stored in a barn and was last licensed in '75. My first question is, how do I keep the seat in its original condition. There are no tears or signs of fading. The material still seems very flexible. The second is, what is the best way to unstick the pistons? I've pulled the heads and one of the cylinders looks fairly good. The other piston is about a 1/4 inch from the top. I'm thinking of using some PB Blaster around the rings to see if that will help. That is, if the pistons are my problem and not the crank. The trans is good, as it shifts thru all the gears. Thanks.    Jim

[Richard Clark BS parts]

Jim

Welcome to the site, you will find a lot of nice guys here, with lots of BS, that is knowledge!!!!

Check out this message link as there is some good information for you:

http://bridgestonemotorcycleparts.com/index.php?topic=772.0


Questions? or need Bridgestone parts? call:

Richard Clark
812-944-1643  8am-6pm EST Weekdays

[Toystoretom]

Hi Jim!

I'm going through the same thing with the stuck piston problem. The link Richard sent you to is some of my efforts to get things unstuck with lots of advice from longtime members. I won't rehash all that here but I will say that you might want be careful with yours, if you have one piston at almost the top of the bore, that means that the rod for that piston is almost straight up and down. That puts it in a position to get bent if you were to hammer on it and the crank doesn't turn.

You'll get it loose.... they are such cool bikes which makes worth the time and effort!

BTW, welcome to the site and see ya around!

Tomo

[poppaweelee]

Hi Tomo
    Thanks for the info. As my luck would have it, the right piston is a TDC so I sprayed the ring area, of both pistons, with PB Blaster and am going to let it soak for awhile. I noticed that the pistons rock sideways very slightly, which is encouraging. I was looking at the parts pictures and noticed that the right end of the crank has a nut on it. I may take the right side off and see if the I can work the end of the crank back and forth to get it to move that way. I really don't want to pull the jugs, but if push comes to shove I may have to.

Jim

[RebusCom]

Typically they aren't stuck real bad, being the cylinders are chromed aluminum instead of iron.  Don't get to wild with it and damage the chrome bore.  If needed, tap the pistons with a wooden drift, not metal, but be aware that it may be the crank that is seized, not the pistons.  Remove the cylinders.  You'll need to inspect them and almost certainly if the pistons are stuck they may have been damaged in a seizure that resulted in the bike being parked in the first place or at the very least the rings will be stuck in the grooves and that will need to be corrected.  You'll also be able to differentiate piston seizure vs. crank seizure by pulling the cylinders.  If you remove the right cover to get at the pinion nut as planned (note that special tools are needed to remove the clutch) you'll be able to feel the crank movement once the cylinders and pistons are removed and the crank is disengaged from the tranny.  It should be very smooth with no "catching" or binding.  Outer main bearing failure is a common failure mode causing seizure when the bike runs without sufficient lubrication.

If you get the cylinders and pistons removed, I recommend only going as far as removing the right carb cover and pull the clutch plates, which need to be inspected anyway, and then feel the crankshaft rotation for roughness (no special tools needed).  That should give you a good idea if a main bearing came unglued without removing the clutch basket and right case cover.  If it's only a top end problem you won't have to go any farther into the engine, unless it's something you really want to do anyway.

Scott
http://www.bridgestonemotorcycle.com

[poppaweelee]

Well, I found out that the pistons weren't stuck after all. I pulled up on the cylinders and they came loose from the base fairly easy. I lifted them up just enough to see a wiggle at the big end on the crank. So the rod area seems to be ok. So, I took the end of the clutch off (left the plates on) and found the inner hub turns but the basket doesn't. This tells me that maybe I have a seized crank bearing or a problem between the basket and crank. I hope the problem isn't in the kickstart area. I guess my next step would be to pull the right side housing off and get to the end of the crank.
Jim

[Toystoretom]

To me... that is almost good news. I'd rather deal with a bearing than try to replace the cylinders, I'll bet Richard has boxes full of crank bearings.

[poppaweelee]

I decided to clean up the bike and I must admit, it cleaned up rather nicely. Now I've decided to pull the engine so it will be easier to work on. My question is, do the exhaust studs need to be removed to pull the engine out or can the front be tipped up a bit to clear the frame. I plan on removing the ignition switch and horn for better clearance.

[reed]

Poppaweelee
No you dont have to remove the exhaust studs to take the engine out of the frame.
It comes out easy after you remove all the engine bolts cables and wiring etc.
Thanks.
Reed.

[poppaweelee]

Thanks, Reed.

[reed]

Poppaweelee
With the engine out you can check out the points and condensers also clean and set the float levels on the carbs!
Look at the engine sprocket mine was well worn on my GTR.Richard keeps them in stock.
Thanks.
Reed.

[old smokey]

the engine removal steps are in the service manual. mostly obvious wires and cables. last step it says is to remove it out the left side.

[poppaweelee]

Thanks for the info guys.
Got the engine out and took apart the clutch. Found I have one broken friction plate. So there's one problem. A guy at the local bike wrecking yard said Suzukis from the same era possibly used the same plates. Any truth to that? Will any other bikes interchage? How do you prevent the clutch hub from turning so the nut can be taken off? If I had a worn out clutch steel, I would make my own tool. Thanks.
Jim

[reed]

Poppaweelee
I don't know about Suzuki friction plate most friction plates are wet or in oil the Bridgestone has a dry clutch.
So try Richard first!
Thanks.
Reed.

[reed]

Poppaweelee
There is a Kawasaki clutch tool that will work!
That's. what i use i will get you the part no
It not expensive.
Thanks.
Reed.