How to tell the difference between 1200 and 1250.

[steelbullet]

Just bought a new legends car it has a yamaha motor but I can't find anything showing the cc's on the motor. The head bolts don't appear to be tagged or drilled with a seal tag. Just curious how to tell which is which.

[thunder938]

Front of the head and the cam chain tensioner, under the carb will be a alum. tag wired to the motor

[racerrad8]

what is the serial number?

Randy - RPM

[knoxracing]

I think we are confused, he is not sure what he has, thats his question. There is a serial number on the motor, kind of below the carbs toward the front of the engine. Also the majority of the 1250 have four emission ports by the spark plugs. they are blocked off but they are obvious. The seal would be hanging on a very short wire on the very front of the engine, it act as a lock. The engine number would be helpful.
Dennis Knox
Buckeye Legends
330-310-9212

[racerrad8]

Well,

Here are the other indicators.

1) The serial number boss. (1250 is flat/parallel with case) (1200 is on a 45 degree angle)
2) The serial number will start with a "P" for the 1250 & a number  for a 1200
3) The cylinder, at the cylinder head gasket on the exhaust side will be cast "1250" or "1188"(1200)
4) The shift shaft will be approximately 3 5/16" extended from the case for a 1250 and just under 2" for a 1200.
5) Most of the 1250's have the EGR ports, but they all have the more square fin detail at the ends of the head compared to the rounded 1200.
6) While interchangeable, the 1250 V/C is silver with the green grommets and allen head bolts while the 1200 is black and the seal is part of the bolt.

There are a couple of minor details within the engine but they cannot be checked without disassembly.

Randy - RPM

[justfreaky]

With no seals or tags, my guess is that it is an open engine. That would rule out the 1250.
To find the year and exact size, as is suggested, a serial number would be helpful.

Steve

[steelbullet]

Motor serial number is  4JN-001368

[VMS Motorsports]

1200

[steelbullet]

1188 stamped on motor under exhaust port. Thanks For your help guys