Steen Alsport engine question

[Tether]

Yesterday I picked up a Steen Hodaka 100. It is a roller with the engine removed and partially disassembled (cylinder and side covers removed). The bike is in fairly nice condition and mostly complete with a new seat and fenders. Very nice pipe.
The engine appears to be in excellent condition. The engine number is M3570. I thought the M prefix was a Super Rat engine? I would have expected the Steen to have an “E” prefix. The top end is not a Super Rat.
Are there any Steen people out there that can tell me what I have here?
Bob

[thrownchain]

Yes, "M" is rat cases. You should have an "E" motor to be correct.

[thrownchain]

Although you could have a "peppy" Steen if you want to redo the rat motor.

[taber hodaka]

M3750 would be for a model 93 Super Rat one of the first series of super rats produced. ---Clarence

[Tether]

Thanks guys.
I was searching for a M motor when I was building my Super Rat, now I get one by accident.

[thrownchain]

At least you can use it and put it to good use.

[Tether]

Yes, I’m not sad about getting a Rat motor.

[viclioce]

I wonder if you ratted it back if it would run great with the Steen pipe? Just curious.... Victor