Author Topic: 86 KX250 motor>88 KX250 frame  (Read 2903 times)

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white rat

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86 KX250 motor>88 KX250 frame
« on: December 30, 2007, 12:55:19 AM »
Before I rip a good running bike apart, will the motor from my 86 fit in my 88? Will the 88 carb and pipe fit the 86 motor?

Cheers

Offline The Flyin Hawaiian

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Re: 86 KX250 motor>88 KX250 frame
« Reply #1 on: December 30, 2007, 07:17:20 AM »
The 88 carb was a Keihin PWK39 crescent slide carb where as the 86 was a round slide 40mm Mikuni. I dont see why you couldnt make it work. May have to rejetand the carb may not fit into the 88 airboot properly. Cant help you with the pipe and swap question. Ive been keeping an eye out for a 86 250, Id like to restore one someday.
A couple of 03 and 04 KXs, a few YZs, 3 PE 400s, a DR and a TS.

Offline CR480R

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Re: 86 KX250 motor>88 KX250 frame
« Reply #2 on: December 31, 2007, 12:17:25 AM »
I dont know about the bottom and top engine mounts, but I do know the front mount is in the same location... The '88 intake boot and carb will work, but the pipe will not fit without mods as the angle is different on the exhaust port exits... The pipes might also be tuned slightly different because of the differences in bore and stroke... You might try fitting the '86 pipe into the '88 frame... I wouldnt be surprised at all if it worked...
« Last Edit: December 31, 2007, 12:25:18 AM by CR480R »

Offline CR480R

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Re: 86 KX250 motor>88 KX250 frame
« Reply #3 on: January 14, 2008, 09:07:58 PM »
are you parting the '86?  If so I am interested in the frame...