Ross’ 1975 CB750

[Galactica]

So having the gasket on order, I decided to open up the transmission cover.  Mine is a #3 cross head not Allen head.  Tight as can be.  Dang.  Now I’m thinking the worst.  Splitting cases and sourcing transmissions/parts.

[kilowop]

Having occasionally had similar situation arise, I was advised to push it over a cliff and declare it stolen.

[hardrockminer]

That would be JIS crosshead?  I use impact screwdrivers if they are tight.

[Steve G.]

  I’m assuming you mean Ohillips head rather than cross head Ross?
  Your entire motorcycle is fastened together with JIS head screwdriver heads. I strongly suggest getting all 3 different sized heads at Princess  Auto. You may need to buy a multi head tip mini box.

   Vessel JIS screwdrivers are the best made .

[Galactica]

Ya, it’s JIS. Thought I’d push some buttons. 

The screw was staked at the factory and you can see it hasn’t moved.  I thought it would be too good to be true.  So I’ll get the gasket and ride it a bit more maybe, to try a get a definitive diagnosis.  But I’m pretty sure I’m looking for a transmission or parts there of.

[Twisted_Twin]

A trick from the Bevel Ducati guys that I found when I was trying to get the clutch in my 860 to stop slipping (it worked) .

Those clutch plates probably sat dry and stuck together for a long time.

Before spending a pile of money on transmission parts, I'd try pulling the clutch friction discs out and soaking them overnight in some ATF.

Transmission fluid has friction modifiers in it that are specifically for wet clutches. Engine oil doesn't have this and since it's a unit engine....

Won't cost much and beats tearing down the transmission.

[Steve G.]

  JASO MA and JASO MA2 rated engine oils both have specific additives for wet clutch operation, and longer chain molecules for gearbox operation.

  Ross, are you concerned that you may have a bent shifter fork?

[Galactica]

Could be a bent shifter fork.  Most likely if a fork is bent, it’s because the dogs and ears are worn, then the gears slip apart and bend the fork.  One problem causing the other, I’m thinking.

[Steve G.]

 Splitting the cases should not be taken lightly!!

[Galactica]

Shawn, the clutch has been working fine.  It’s possible that it is to blame.  That would be an easy fix.  It doesn’t slip so much as chunk and juddder, and not all the time.  When I get the transmission cover gasket, I’ll ride it some more.  It could well be the clutch.  That would be my hope, but I’ll do some research in the meantime.

Steve, splitting the cases is the last resort.  I’ll certainly exhaust all other options first.

[hardrockminer]

Another check before splitting the cases....drop the oil pan to see if there are any metal bits in there.

[Galactica]

The shift cover gasket will be here hopefully by the end of the week.  At least then I can ride it a bit more to see what’s going on.

In the meantime, since I’d have to order a clutch cover gasket just to access the clutch discs, I placed another order.  I ordered gasket, clutch removal tool, friction discs, springs, tab washer.  And some rubber parts for neighbour’s bike.  Should be here in a couple of weeks.

[Galactica]

So I got parts today from VINTAGECB750 in Ontario.  I had to wait for the special tool to remove the centre nut. 

I dismantled the clutch and measured the discs and plates.  They were all right on original spec.   The inexpensive (cheap Chinese crap) friction discs are barely within spec thickness and the friction material is much narrower than the original.  So I cleaned and sanded the plates with 600 grit paper, cleaned and oiled the friction discs, and reassembled it all.  The I measured the springs, they were well within spec, but the new ones were a bit taller, so I put them in.  Only 300 miles on the oil but I changed it as well. 

I ran the bike up and down the lane and all seems well.  We’ll see how it goes over time.  I’m confident that the clutch is fine.

[Galactica]

So, yesterday at our midweek coffee, someone asked me how much my paint cost.  Rumours floating around that I paid around $4,000.  Not so.  But…I did pay quite a bit.  Now, I can rationalize and justify, but what’s the point.  I still cringe at the outlay. 

The short answer is, I paid $1500.  That was just to apply the tank stripes and paint.  If I’m honest with myself, just sandblasting, stripes, paint itself, and paint shop cost me $2173.94.  I also had to buy new side covers as well as the originals weren’t really repairable, $116.17.  So total $2290.11 as it sits. 

Unbeknownst to me when I started the process, there are complete body kits available from Yamiya in Japan.  Unfortunately the Planet Blue sets are sold out, and have been since I first found out about them.  Totally worthwhile, and in hindsight, a route I should have taken.  Could have had it delivered to Point Roberts for just under $2,000.  I certainly could have recouped some of that cost by selling my original tank, the original side covers are worthless, I have them hanging on the wall in my garage for artwork.  The Yamaha kit does not include emblems, lower tank trim, or gas cap.  All of which I also bought. 

Other than the $300 difference in cost, I’m really pleased with the results.  And I know that at least I’ve retained the original fuel tank.  I put some $ into the local economy as well. 

So, no, I didn’t pay $4,000 for my paint. 

[hardrockminer]

I had two sets of Z1B colours done by Michael in Surry for $2,500.  I supplied the paint but I don't remember how much I paid for it.  That was a few years ago..maybe 2016?  So overall your price is OK I think.