Measurement of the back motor mount

dnmac1999 · Post by **dnmac1999** » March 13th, 2010, 8:07 pm

Was wondering if anyone knows the measurement between the two bushings for the rear motor mount that the swing arm bolt goes through for the 500?

CR500R7 · Post by **CR500R7** » March 13th, 2010, 8:25 pm

2001 CR500 rear motor mount measures 74mm.

As far as I know 89-01 all have the same measurement.
I hope this helps.

dnmac1999 · Post by **dnmac1999** » March 13th, 2010, 8:29 pm

It does help, thanks.Trying to get a 250 in a gen.4 frame and was wondering if they were the same, hoping to make it easy for me from all of your guys work. I guess it isn't going to be easy.

CR500R7 · Post by **CR500R7** » March 13th, 2010, 8:32 pm

It's not that hard, what measurement do you have for the 250 engine you want to use?

dnmac1999 · Post by **dnmac1999** » March 13th, 2010, 8:36 pm

I am coming up with 81mm and 84mm, using a caliper and a tape. Not sure which one to go with.

CR500R7 · Post by **CR500R7** » March 13th, 2010, 8:48 pm

The caliper would be your best measurement.
What year CR250 engine have you got, if it's out of a 02-07 CR250R 84mm would be correct.
I had to add 10mm to the measurement of my 01 CR500 engine, 5mm either side to mount this into an 07 CR250.

dnmac1999 · Post by **dnmac1999** » March 13th, 2010, 8:58 pm

I have a 97 cr 250, I think im just going to have to do it the old way and bolt up the rear wheel and use a straight edge, then cut the One or both of the swing arm collars to fit.

CR500R7 · Post by **CR500R7** » March 13th, 2010, 9:07 pm

I'm fairly sure you won't have to cut anything but you may have to make spacers to take up the gap.
For the rear of my 500 engine I had new bushes made for the rear of the engine that are 5mm longer to take up the gap of 10mm, 74mm compared to 84mm.
You may also be able to mix and match the bearing bush in the swingarm as well.
It depends on the width of your 250 engine and what offset you need to centre the CR250 engine in the CRF Gen 4 frame.
If the CR250 engine is 84mm and the offset is correct you won't have to machine or cut anything at all.

dnmac1999 · Post by **dnmac1999** » March 13th, 2010, 9:13 pm

Well I hope it goes easy. Ill see tomorrow. How do you post pictures on here, would like to show you guys what ive done to the frame. Honestly it looks easier to put the 500 in these things then the 250.

CR500R7 · Post by **CR500R7** » March 13th, 2010, 9:24 pm

I'm the wrong person to ask about posting pics, technology HOPELESS.

The 250 shouldn't be any harder than the 500 they both share the bottom engine mount holes spacing.
If I'm correct in assuming the rear of a 97 engine is the same as an 02-07 all you need to do is leave the 59mm bearing bush in the right side of the swingarm and get a 54mm bush for the left side of the swingarm

52141-KZ4-J40 right side bush 59mm long

52142-KZ4-J40 left side bush 54mm long

Take a gander in the Beer can section ( AFs ) under STICKY: Gen 3 OEM Swingarm spacers.

The Gen 4 CRF250 already has the 59mm bush on the right side.

dnmac1999 · Post by **dnmac1999** » March 13th, 2010, 9:28 pm

Ill try that tomorrow, Thanks I will let you know how it goes.[/img]

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Measurement of the back motor mount

Measurement of the back motor mount