Unidentifiable IAME BM PLEASE HELP

[Mykartfarts]

Hello all, first post.
So I traded a drone for a kart (wanted one whole life), and I found a guy to trade me a badass kart for my drone ..(Nice drone)
It’s an IAME kart, possibly a ka100, but he told me that when he bought it the guy told him it was a puma 100cc? Now there is a puma 100cc but it looks like in America that’s a rare find. So I went hunting for serial numbers. They are not on the front of the motor like one tech sheet said, the only numbers I found were on the backside, opposite the clutch. On each “motor mount block” looking thing, there are a sequence of numbers following a single letter.
M4922 on left and B3957 on the right. Now I have searched the interweb like nobodies business and I can’t even find a hint as to what this is. It’s powerful, except the clutch is now gone and they’re not cheap but I need to know the model before I can buy one.

Can anyone help?

 

[itsid]

any racing clutch with the correct bore will do (well any adjustable two stroke clutch that is)
horstman two disc dry or wet will serve you well.

Now that outof the way.. as soon as I can I'll check what I can find out with those numbers.

Any chance you can take a few well lit pics of the engine (most noteworthy the crank case)
head and cylinder usually fit inbetween certain models and just going by that might lead to a false identification (careless pre-owners assumed)

'sid

[EDIT]
Well.. the deeper I dig the less I know
That thing certainly is some crossbred..
We can tell for sure it's a iame BM Atlas (the BM badge gives that much away)
(Mario Bertuzzi btw...)
it's certainly not a KA100 (that'd be a Parilla.. so no BM badge would make sense)
and unlikely a Puma (that'd be a Comet then again BM badge rules that out)

And it's an early one (they won over 50 world championships by now...so five must have been some while ago)
Since BM was aquired by iame sometime in the late seventies early eighties or such,
merging it with their atlas series I think it's fair to assume "roundabout that time"
BUT that badge covers a reed valve port (or it's cast at least)
and that engine clearly is a piston port...
If I go by the head and cylinder however it's a Komet or a Parilla
(Komet are the only engine numbers I can find starting with an M)
you see.. nothing but confusion I'm afraid.
that head is most often used on rotary valve engines (yet another "NO, NOT IT")

There's this german guy that collected nearly all iame homologation documents available..
If I get hold of him, I'll let you know

 

[Mykartfarts]

Just saw your response, sorry so late. Yes, I was worried this was some type of hybrid! It runs like a bat out of ****, but yes, I am very new so have no idea. I will shoot some more clear pics tomorrow. Figures I get the weird one!

 

[itsid]

not to worry...
many cylinder and heads have moved within the iame range of engines..
since most fit most crankcases people liked to pick what's at hand to make an engine run again..
that one is only interesting since the reed port was clearly cast (maybe not cut)
and then badged by iame themselves..
So the crank case itself might have been part of different lines of engines too.

if all else fails, you can still contact iame.it once you need a spare or replacement part.
they can not only identify that engine for you
(since for all I know they still keep all documents since day one)
but also hook you up with the shop manual for your engine.
And then it's a matter of searching for part numbers on the internet... tedious but doable.

'sid