Turning a 502 into a 503

These posts document restoration experiences of our members
User avatar
Go Go Diablo
Site Admin
Posts:1830
Joined:Fri Feb 22, 2008 12:47 am
Location:Sobieski, Wisconsin
Contact:
Re: Turning a 502 into a 503

Post by Go Go Diablo » Tue Jan 31, 2012 11:07 pm

As mentioned earlier, the PTO shaft on the 191R motor is larger. I refer to it as a 30mm. Finding a Salsbury clutch with a 29mm bore is rare, so I take the clutches apart and have the bore machined out to fit the larger shaft.
DSC01499.JPG
DSC01499.JPG (164.16KiB)Viewed 4009 times
DSC01498.JPG
DSC01498.JPG (164.91KiB)Viewed 4009 times
I use a 29mm bore on the clutch so when mounted, the clutch is about 3/8" to 1/2" away from the motor housing. A 30mm bore will let the clutch hit the bolts on the starter.
DSC01500.JPG
DSC01500.JPG (164.96KiB)Viewed 4009 times
Too many Diablos and parts to count.
Yamaha 600 SX

User avatar
Go Go Diablo
Site Admin
Posts:1830
Joined:Fri Feb 22, 2008 12:47 am
Location:Sobieski, Wisconsin
Contact:

Re: Turning a 502 into a 503

Post by Go Go Diablo » Thu Mar 01, 2012 9:36 pm

I guess the last thing to talk about is the wiring.

Obviously the wiring from a 502 to a 503 is different. Without a lot of typing, it would be difficult to explain all that is needed regarding the wiring changes. Each time I restore a 503, I run all new wires anyway. So if you need a wiring diagram, just give me a shout and I'll get you one.

The short answer about the wiring is that you need a new key switch. With this key switch, I also use a plug in harness. The harness protects the terminals on the back of the key switch from the bare steel wrench swinging around while doing things like changing spark plugs and such.
DSC01495.JPG
DSC01495.JPG (163.9KiB)Viewed 3996 times
I like using the battery terminal protectors too for the same reason.
DSC01502.JPG
DSC01502.JPG (164.86KiB)Viewed 3996 times
Wiring is needed to the Voltage Rectifier and the lights.
DSC01496.JPG
DSC01496.JPG (164.89KiB)Viewed 3996 times
Too many Diablos and parts to count.
Yamaha 600 SX

User avatar
Go Go Diablo
Site Admin
Posts:1830
Joined:Fri Feb 22, 2008 12:47 am
Location:Sobieski, Wisconsin
Contact:

Re: Turning a 502 into a 503

Post by Go Go Diablo » Thu Mar 01, 2012 9:40 pm

That's it! Make these changes and your electric start Diablo 503 is ready to roll!
DSC01510.JPG
DSC01510.JPG (163.32KiB)Viewed 3996 times
DSC01509.JPG
DSC01509.JPG (164.88KiB)Viewed 3996 times
DSC01512.JPG
DSC01512.JPG (165.17KiB)Viewed 3996 times
Bruce
Too many Diablos and parts to count.
Yamaha 600 SX

Post Reply