Hate to do it but...

[bikegeezer]

I haven't been able to get the GT500 to stop leaking oil around the OD of the left crank bearing. It was doing it when I got the bike, and it started again about 2,000 miles after rebuild. Another strip down didn't show any visible damage. Put back together with all new seals and O rings, and it still leaks where the crankcase clamps around the bearing OD. Maybe this is why the case looked like it had been stripped repeatedly over the years with only 5,000 miles on the bike?

So I'm off to have my machinist turn a T500 crankcase into a GT case. Really would like to use the original, but I'm sick of screwing around with it. The case is probably porous.

Stu

[diamondj]

Okay two dumb questions:

1. Did you use three bond (Hondabond, yamabond, etc...) between the sealing surfaces on the crankcases when you reassembled?

2. Did you check the cases against a flat surface to make sure they are not warped?

I *MAY* have a spare GT500 crankcase if you can't fix yours....

Jim

[bikegeezer]

Okay two dumb questions:

1. Did you use three bond (Hondabond, yamabond, etc...) between the sealing surfaces on the crankcases when you reassembled?

2. Did you check the cases against a flat surface to make sure they are not warped?

I *MAY* have a spare GT500 crankcase if you can't fix yours....

Jim

Jim,
The answer to both questions is yes. I appreciate your offer, but I have a couple of good T500 case sets that I modded to take the extra 200cc of oil. As long as the engine number isn't going to match the frame anymore, I may as well use what I already have. Besides, unless someone knows what to look for, they'd never know the difference. Oh - I'm gonna change out the entire left bearing, too. Taking no chances.

Stu

[diamondj]

Okay two dumb questions:

1. Did you use three bond (Hondabond, yamabond, etc...) between the sealing surfaces on the crankcases when you reassembled?

2. Did you check the cases against a flat surface to make sure they are not warped?

I *MAY* have a spare GT500 crankcase if you can't fix yours....

Jim

Jim,
The answer to both questions is yes. I appreciate your offer, but I have a couple of good T500 case sets that I modded to take the extra 200cc of oil. As long as the engine number isn't going to match the frame anymore, I may as well use what I already have. Besides, unless someone knows what to look for, they'd never know the difference. Oh - I'm gonna change out the entire left bearing, too. Taking no chances.

Stu

Stu,

I'm pretty sure the GT500 cases are milled differently on the PEI side to clear the PEI unit. Are you going to modify the T500 cases to fit the GT500 crank & PEI?

Jim

[bikegeezer]

Stu,

I'm pretty sure the GT500 cases are milled differently on the PEI side to clear the PEI unit. Are you going to modify the T500 cases to fit the GT500 crank & PEI?

Jim

That's exactly what I'm having the machinist do. The seats for the stator plate need to be cut to a depth of 15.75mm below the edge of the case. The diameter is already correct, but I may have to drill & tap the screw holes deeper when he's done with it. No big deal there. Aside from that, I built up the oil dam in the transmission 10mm to accommodate the extra tranny oil.

Stu

[diamondj]

Stu,

I'm pretty sure the GT500 cases are milled differently on the PEI side to clear the PEI unit. Are you going to modify the T500 cases to fit the GT500 crank & PEI?

Jim

That's exactly what I'm having the machinist do. The seats for the stator plate need to be cut to a depth of 15.75mm below the edge of the case. The diameter is already correct, but I may have to drill & tap the screw holes deeper when he's done with it. No big deal there. Aside from that, I built up the oil dam in the transmission 10mm to accommodate the extra tranny oil.

Stu

Cool! If you change your mind, let me know. I pretty sure I got two GT500 cases with a race bike project I bought recently....

Jim

[bikegeezer]

Jim,
Good to know you have spares. I still may buy one from you if the machinist messes up the case. I'll post a few pics when I get it back.

One reason I went with this case is because I was the one who tore the engine down. It was bone dry in that left seal area, and it appeared to have never been dismantled previously. The original case looks like it was torn down at least three times before I got it (3 different colors of case sealer), and the mating surfaces were all scarred up.

Stu

[bikegeezer]

Jim,
I got the case back from the machine shop. The PEI parts now fit in there just right, so I'm going to use the case.

Stu

[bikegeezer]

Here are pics of the modded crankcase and the timing mark I had to punch at the top. Click on the pics to go to larger images.

Stu

[diamondj]

Hey Stu,

Looks good! Glad it worked out for you. Hopefully this will finally fix your oil leak.

Jim