Author Topic: 76 yz250 head interchange. 77 78 fit?  (Read 2467 times)

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Offline steveo247

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76 yz250 head interchange. 77 78 fit?
« 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?
« Last Edit: August 10, 2011, 09:02:25 pm by steveo247 »

Offline motomaniac

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Re: 76 yz250 crank interchange
« Reply #1 on: August 07, 2011, 10:55:17 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 .

Offline GMC

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Re: 76 yz250 crank interchange
« Reply #2 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
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Offline steveo247

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Re: 76 yz250 crank interchange
« Reply #3 on: August 08, 2011, 08:00:17 pm »
thanks for the info gentlemen. much appreicated

Offline steveo247

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Re: 76 yz250 head interchange. 77 78 fit?
« Reply #4 on: August 10, 2011, 09:02:55 pm »
bump new question  ::)

Offline motomaniac

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Re: 76 yz250 head interchange. 77 78 fit?
« Reply #5 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.

Offline GMC

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Re: 76 yz250 head interchange. 77 78 fit?
« Reply #6 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

G.M.C.  Bringing the past into the future

Shock horror, its here at last...
www.geoffmorrisconcepts.com

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http://www.geoffmorrisconcepts.com/8/news/

Offline steveo247

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Re: 76 yz250 head interchange. 77 78 fit?
« Reply #7 on: August 11, 2011, 09:58:47 pm »
once again, many thanks!

Offline motomaniac

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Re: 76 yz250 head interchange. 77 78 fit?
« Reply #8 on: August 11, 2011, 10:19:47 pm »
Webco heads are the best for these bikes.

mx250

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Re: 76 yz250 head interchange. 77 78 fit?
« Reply #9 on: August 11, 2011, 11:03:21 pm »
Webco heads are the best for these bikes.
......or some one with good knowledge of modern squish bands theory etc and re-machining ;).

IT400C

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Re: 76 yz250 head interchange. 77 78 fit?
« Reply #10 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.