RM 250 A,B or C?

[evo550]

Whats the visual difference between the rm 250 A,B and C?
Looking at one at the moment, seller says 1978 "C" , numbers say "A"
Google brings up the same bikes regardless of A, B or C search.

[LWC82PE]

76A - round tube straight swingarm. Axle is right at the bottom of the forks. Axle threads into right slider. Handle bars direct above fork caps.
77B - more of a boxed section swingarm with slight bend in it. Axle is right at the bottom of the forks. Axle goes through slider and uses a nut. Handle bars direct above fork caps.
78C - New air forks have the extra length below the axle and fork boots. Still has alloy tank. Handle bars direct above fork caps
78.5 C2 - alloy swingarm, plastic tank, floating rear brake. Handle bar mounts are rubber mounted and laid back behind extended air fork caps.

Plenty of brochure pics here

https://onedrive.live.com/?id=407D7EF0965D3991%213198&cid=407D7EF0965D3991

[suzuki27]

250A& B have leading axle forks. 125A has inline forks. 125B has leading axle forks with more length extending below both the 250A&B. Not too many 250C's in oz compared with the C2's

[suzuki27]

250B has best motor IMO . The closest they got to to the euro motors. Easy power

[LWC82PE]

Yeah A and B have leading axle forks too but i just described them as having the axle at the bottom compared to the C forks where there is more underhang below the axle. Never intended to indicate they were 'non leading axle forks'

[evo550]

http://www.ebay.com.au/itm/Suzuki-RM-250-C1-1978-/322272188028?hash=item4b08eb567c:g:KpoAAOSwPCVX5xb8

this has "A" numbers but more underhang on forks. Pre '78?

[LWC82PE]

The only suzuki forks that look like that and are pre 78 legal are RM125B forks. Easiest way to confirm if they are 77 125 forks is to measure the slider from axle hole top top of the slider. They should measure 295mm. 250C are 315mm. There are also cast numbers near the axle holes which can also ID the forks.

The forks and triple do look either like 77 125 or 78 250 C but only the slider length and cast numbers can confirm exactly what thay are. I have both 125b and 250c forks, so know the differences. Those forks look quite long too. They may have the negative springs removed or have longer damper rods in them. Even if they are 125b forks, they possibily will need correcting to stock travel for 9in limit, if they are not stock at the moment,  if you are intending to race.

That bike has a 79 or later tank on it.\

Pipe is not a 76 item either.

[pmc57]

I'd say it's a RM250A with some later model forks and rear shocks (look like PE shocks maybe the same with forks).
Round section swing-arm is 250A, as well as the motor.... give away is the cooling cut-outs in the barrel fins, these were a feature on the '76 A and deleted in the B and C motors.