Vintage Dirt Bike Q & A

i have a 74 mt250 with a freshly rebuilt motor, and i was just wondering if they're were any other differences between the mt and the cr in 74 aside from the motor? i know there are some aesthetic differences and have already removed the groovy turn signals and tail light but i would also like to ditch anything that doesn't help go faster, or stop shorter! love the raw look of the old cr's

I think the frame on the cr250 is lighter. Aluminum vs. steel wheels, different carb, air box, and the motor differences.

there are many differences between these two bikes.
it´s like beetle and porsche.

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80 CR250Ra
80 CR250Ra
78 CR250R
80 CR80
82 Bultaco Sherpa 340
78 Bultaco Pursang 250 MK12
76 Bultaco Frontera 370 MK10
76 Bultaco Alpina 250
73 Bultaco Lobito 125 MK6
76 Suzuki RM125A
90 Kawasaki KX250

Diggin the vdub reference. Do I need the rectifier?

With no lights or battery, you shouldn't need the rectifier at all.

If you're looking to unload the groovy turn signals, I know someone who might be interested in them.

Ray

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'74 CR125M (175cc), '75 MR175, '82 RM250Z, '08 YZ250F, '14 Zero FX electric, '14 Zero MX electric, '18 Alta MXR electric

I spent a lot making my mt250 like a cr250 and honestly I dont like it. I need to modify the frame because it has terrible head shake under acceleration. I am assuming its from the steering angle but really I dont know for sure. I did make the rear end a tad taller but not the front so I guess moving the shock mounts to lower the rear might work too. I only did this to an mt250 because I wanted a bike that looks like a cr250m but can be used on the street.

Hi all, I have a 74 MT that I use for dirt tracking and I was wondering if anyone has dropped a CR motor into an MT, encountered any problems etc?
Thanks in advance.

the 73-74 CR250 engine will bolt right in providing you get the CR250 air cleaner,CR250 34 mm carb and pipe from the CR or the top end from a 73-74 CR250 will also bolt on to a 74-76 MT250 lower end.to get it to run strong you will need to use the CR250 carb and pipe.

i ran my 1974 MT250 with a 73 CR250 complete engine assembly with a NOS Kehin 34 mm CR250 carb and stock CR250 air filter and a DG 73-74 CR250 pipe on it for a while.it was very quick,setup like that!

putting the 28 mm MT250 carb and stock pipe will choke the hell out of the CR250 engine so i don't reccomend doing it that way.

many CR250 engine parts like the Clutch assembly and straight cut primary gears can be used in the MT250 engine,the transmission gears like using the MT250 1sr and 5th gears will give a low gear for plonking and 5th will give it a eye watering top speed of over 80 mph.

it is really fun to mix and match MT and CR250 parts.

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(2) 1968 DT1 1970 RT1M,1970 DT1C 1971 RT1B Enduro 1974 MT250 1974 DT250A (2) 1975 DT400B 1974 DT100,1978 DT175
1975 CR250M1 1979 CR250R 1979 Kawasaki KZ400H1 Jesus is Lord!!