671na lay-down motor

Hello all
I was wondering if a 671na lay down or slant motor has air box drain tubes. If so where would it be located on the motor?

They will be in the same place as a "stand up" or vertical installation, at the bottom of the air box. Not sure what you have but the only "slant" installations I've seen were in buses and were only tilted 15 degrees from vertical for low profile clearance purposes and utilized a "sub" oil pan adapter to compensate for the angle. If yours has one of those, look around the parting line for that adapter and the engine block for the drains.

It doesn't matter what type of set up they have, the Detroit 2 stroke HAS to have a blower box air drain. Some uninformed people use pipe plugs to seal them up thinking they are "leaks" but that only leads to misery. If that is the case with yours, find it/them and unplug and clear it out if it is not moving air.

Good luck.

thanks
i'll give it a look

Yeah, right above the oil pan or at the base of the block. Look for 1/4" pipe plugs if you don't see any tubing or those little needle valves with the butterfly wing looking handles. Restoring flow out of the air box will head off all sorts of problems for sure.
Good luck and let me know how you make out.

Sorry, I may have mislead you. I had a brain cramp for sure when I was describing where the air box drain HOLES are located. I indicated that they were near the flange for the oil pan or adapter. That's about where the end of the TUBE should be. Look for the HOLE a bit higher up than that, just below the level of the inspection covers. Sorry for any inconvenience.