does anyone know what the engine numbers are for mk 1 and mk2 crm250?
i got a mark 2 crm but when i checked the carb it has jetting for a mark 1.
i want to know if has an earlier engine or the wrong carb.
is there any difference between the engines?

Engine numbers follow frame numbers - viewtopic.php?f=20&t=5282&p=32257#p32257

There are differences between engines most of which are small. Most important is ignition timing.

blimey that was quick, thanks for that, i should get it running tomorrow, once i do i am going for full rebuild, do you know anyone who has an ignition switch/speedo/idiot lights?

Knack is the forum GOD if he says it it is true it is , i am only an admin assistant and John is the brake GURU

FAQ section covers all things CRM

Jeram is covering the tuning section if it works( but i doubt it if his idea works i will eat humble pie)

and set about tuning mine

What BoR says isn't true I do make mistakes .

The CRM FAQs section is well worth reading. viewforum.php?f=20

Jeram is in the process of making a CR/CRM engine which will probably produce quite a bit more power than the original CRM. A lot depends on how well executed the modifications are made and how reliable the end product is.

back off road wrote:Knack is the forum GOD if he says it it is true it is , i am only an admin assistant and John is the brake GURU

FAQ section covers all things CRM

Jeram is covering the tuning section if it works( but i doubt it if his idea works i will eat humble pie)

and set about tuning mine

yep i am the one and only brake guru

where should the engine number be?

10 o'clock from the kickstarter shaft. Sticking out of the crancase.

engine is mark one, frame is mark two, does it matter?

No.