Author Topic: smooth out an 87 CR250  (Read 2579 times)

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Offline TheDamo

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smooth out an 87 CR250
« on: June 10, 2013, 04:42:55 PM »
Hi Guys,
Has anyone had experience with smoothing out the power on an 87 CR250?
Some more bottom end and transition to mid range would be nice.
Cheers

Offline Lozza

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Re: smooth out an 87 CR250
« Reply #1 on: June 10, 2013, 05:07:31 PM »
Do you want the easy or the hard way?
Jesus only loves two strokes

Offline Paul552

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« Last Edit: June 10, 2013, 06:44:23 PM by Paul552 »
'77 YZ125D '84 CR250RE '89 CR250RK '84 CR80RE  '09 YZ250F


Offline TheDamo

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Re: smooth out an 87 CR250
« Reply #4 on: June 10, 2013, 07:51:31 PM »
Do you want the easy or the hard way?
Gimme both thanks

Offline Damo

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Re: smooth out an 87 CR250
« Reply #5 on: June 10, 2013, 08:47:33 PM »
Boyesen Rad Valve and Keihin 38mm Airstriker

Offline Lozza

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Re: smooth out an 87 CR250
« Reply #6 on: June 10, 2013, 11:11:53 PM »
Do you want the easy or the hard way?
Gimme both thanks

We'll start with the easy way. Machine a 50mm spacer  minimum 2mm LARGER ID than the exhaust duct outlet, Then fit that between the pipe and the cylinder. Test. Measure stinger/tailpipe ID(usualy 27mm).
Jesus only loves two strokes

Offline whitey 43

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Re: smooth out an 87 CR250
« Reply #7 on: June 11, 2013, 08:28:04 AM »
From what ive heard, you can buy a flywheel weight which screws into the puller thread...It works really well on the late 80s cr 250s, & would smooth your hit out & make the power more useable.

Offline 80-85 husky

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Re: smooth out an 87 CR250
« Reply #8 on: June 11, 2013, 08:31:12 AM »
How is the needle jetting? if its rich it will give a harder hit as it transitions than if its spot on?

got blubbering and drag at 1/4 to 1/2 throttle ???