OzVMX Forum

Marque Remarks => Yamaha => Topic started by: steveo247 on August 07, 2011, 09:46:49 pm

Title: 76 yz250 head interchange. 77 78 fit?
Post by: steveo247 on August 07, 2011, 09:46:49 pm: new question, without starting another new thread with more of my silly questions.

is there any different between the 76 head, and the 77 78 models?
Title: Re: 76 yz250 crank interchange
Post by: motomaniac on August 07, 2011, 10:55:17 pm: Quote from: steveo247 on August 07, 2011, 09:46:49 pm
can someone with one of those programs that search for parts interchangability tell me what other models a 1976 yz 250 crank will fit?
part number # 509-11400-00

thanks very much!

I dont have a program but I have a crank and later one also ,the dimensions are a bit different .Stick with 75/76 .
Title: Re: 76 yz250 crank interchange
Post by: GMC on August 08, 2011, 08:11:07 am: Officially for 2 models, but others may fit!!

Part # = 509-11400-00-00
Part Description = CRANK ASSEMBLY
Model Count = 2
MX250B 1975 250 MX250 Off-Road
YZ250C 1976 250 YZ250 Competition Motocross
Title: Re: 76 yz250 crank interchange
Post by: steveo247 on August 08, 2011, 08:00:17 pm: thanks for the info gentlemen. much appreicated
Title: Re: 76 yz250 head interchange. 77 78 fit?
Post by: steveo247 on August 10, 2011, 09:02:55 pm: bump new question ::)
Title: Re: 76 yz250 head interchange. 77 78 fit?
Post by: motomaniac on August 10, 2011, 09:18:35 pm: the pipe s are different so the 77/78 has fins cut to suit where the 75 /76 doesnt.Internally the combustion dome is off set to the rear on the later models.
Title: Re: 76 yz250 head interchange. 77 78 fit?
Post by: GMC on August 11, 2011, 09:46:11 pm: Part # = 509-11111-70-00
Part Description = HEAD,CYLINDER
Model Count = 1
YZ250C 1976 250 YZ250 Competition Motocross

Part # = 509-11311-01-00
Part Description = CYLINDER
Model Count = 2
MX250B 1975 250 MX250 Off-Road
YZ250C 1976 250 YZ250 Competition Motocross

Part # = 498-15111-01-00
Part Description = CRANKCASE (LH)
Model Count = 4
DT250B 1975 250 DT250 Dual Purpose
DT250C 1976 250 DT250 Dual Purpose
MX250B 1975 250 MX250 Off-Road
YZ250C 1976 250 YZ250 Competition Motocross

Part # = 498-15121-01-00
Part Description = CRANKCASE (RH)
Model Count = 4
DT250B 1975 250 DT250 Dual Purpose
DT250C 1976 250 DT250 Dual Purpose
MX250B 1975 250 MX250 Off-Road
YZ250C 1976 250 YZ250 Competition Motocross

Clutch cover????

Part # = 509-15431-01-00
Part Description = COVER,CRANKCASE (RH)
Model Count = 5
IT400C 1976 400 IT400 Dual-Purpose
MX250B 1975 250 MX250 Off-Road
MX400B 1975 400 MX400 Off-Road
YZ250C 1976 250 YZ250 Competition Motocross
YZ400C 1976 400 YZ400 Competition Motocross
Title: Re: 76 yz250 head interchange. 77 78 fit?
Post by: steveo247 on August 11, 2011, 09:58:47 pm: once again, many thanks!
Title: Re: 76 yz250 head interchange. 77 78 fit?
Post by: motomaniac on August 11, 2011, 10:19:47 pm: Webco heads are the best for these bikes.
Title: Re: 76 yz250 head interchange. 77 78 fit?
Post by: mx250 on August 11, 2011, 11:03:21 pm: Quote from: motomaniac on August 11, 2011, 10:19:47 pm
Webco heads are the best for these bikes.
......or some one with good knowledge of modern squish bands theory etc and re-machining ;).
Title: Re: 76 yz250 head interchange. 77 78 fit?
Post by: IT400C on August 12, 2011, 10:19:26 am: I've riden a 400C with a D head on it and it went well - not sure about the 250, but it shouldn't be too different.