Has Anyone Seen This Before

[shunt]

I don't know if anyone on the Forum has seen this before or has any ideas to what whoever did it was trying to achieve, the back story is, purchased a 125 motor off a guy that buys a lot of Job Lots (deceased estates and the like) who had picked it up in a Job Lot of approx 40 various bikes and assorted parts.
It is Super Combat Crank Cases, Cast Iron Wombat Barrel (mild porting & transfer ports matched to Crankcases) & Carby Manifold, Super Combat Head, Piston is Non Reed Valve, Internal Rotor on Crank (no Ignition Charging Coils [disappointingly]).
At the front of the Ignition side Crankcase (as pictured), there is a steel tube running from under the base of the Cylinder through to the Transfer Port, tube runs straight thru (no check valve or the like).
My plan when I get around to using the crankcases, at present is to just block the hole up, but thought it would be an interesting one to put out there.

Shane

[thrownchain]

Can't see a purpose in that, if nothing else it's a major air leak.

[hodakamax]

Like the Dr. sez, I've never seen that before. I'll take a couple of weird guesses though. How about a nitrous oxide port or maybe the engine had been converted to some sort of pump, driven by a coarse sandpaper belt off the flywheel--I have no idea!

Maxie

[taber hodaka]

Remember when we were experimenting with the diaphragm pumper carbs and it took a pulse to activate them?? But I do not know why you would have the need for two. I used a line to my expansion chamber and it worked. We used snowmobile carbs and they had external adjustments for low and high speed, just like a chainsaw. -----------Clarence

[taber hodaka]

Also the advantage was it would run in any position including on the side or upside down. ---------Clarence

[ossa95d]

Clarence,
I agree that it might be an impulse connection for a pumper carb. There appears only to be only one which would make sense.

[hodakamax]

OK, You guys idea sounds more reasonable than mine. Clarence, did the snowmobile carbs perform well? I never fiddled with them.

Max