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Transmission problems
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Author:  mxgeezer [ Fri May 05, 2006 7:20 am ]
Post subject:  Transmission problems
My freind and I recently rebuilt a 79 CR250 motor from a box of parts.
The only problem it has is it wants to kick out of 3rd and 5th. My buddy says the shift dogs are worn and need to be re-cut or replaced ( I am not talented or brave enough to understand tranny's). Can they be re-cut, and if so who does this? Any ideas on where to find them?
Author:  Jake [ Fri May 05, 2006 6:49 pm ]
Post subject: 
My guess would be replace them. Maybe someone out there can recut them but it sounds complicated to me. You would likely have to add metal and heat treat. Try to get some part numbers and see what's available or watch ebay.

If a shifting fork were bent or worn it may not hold the gear in place. If it has been popping out of gear for a while the dogs could be getting worn.

There should be some links around for westernhill honda.
Author:  Sam427 [ Tue May 23, 2006 5:56 pm ]
Post subject: 
I do backcuts on the gears, but only if they are in good shape to start with and have minimum wear. I change the angle on the drive side of the dog to help suck the gear in place on the shift, it helps to save the life of the gears and you don't miss as many shifts. This was originally started to help save the 73/74 CR250's, I have since done some other engines. The 79 CR250 is a pretty good gearbox, your best bet and the cheapest is to just replace the gears, and if any shift forks have the chrome worn off they should be replaced to. The Honda gears are only case hardened, somewhere around .030 - .040 thick, once it breaks through that case hardening the gear goes really fast. :cry:
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