Just wondering if there was a wold of difference, between a crf 250 bottom end, and a 315 bottom end? ive got a 315 manual on disc, but its not that detailed,

Just trying to gain a bit of knowledge,,

Thanks in advance

i would have thought yes, a whole "wold" apart.

are CRF's not a 4 stroke?

what are you trying to do?

i would have thought yes, a whole "wold" apart.

are CRF's not a 4 stroke?

what are you trying to do?

Hi Paul, ive got an old junker bottom end gathering dust, which has got really rough mains in it,

The crank seems fine, with hardly any play,

But i am really tempted to have a go at spliting it.

i know that the crfs a 4stroke, just thought id gain a bit of under standing from one of their manuals which are ten a penny, I know there will be cost with clutch/crank pullers + splitters, And i know commen sence is screeming at me saying, (just pay some one) but im the keen tinker type,,, cheers clay

1) Go here and find your part number:

http://www.apexmotosports.com/montesa%20parts%20book/e-1.htm

2) Take that part number, then go to http://www.ronayers.com/ and plug it into "Where Used" dialog box to see where this part # is used.

For example, your Monty's con rod small end bearing 91015-KZ3-003 is used on 1990-2007 Honda CR250R. But crankshaft 13300-NN3-000 doesn't come up on ronayers.com, which means it is unique to Montesa.

As a rule, any part number with -NN1- or -NN2- or -NN3- in the middle is unique to Montesa.

Cheers bud, picked up a cr manual, just to get a touch of insight as well,

(think im going to need a bigger kitchin top)