Imco 2 inch shorty on b max drive
 

What is involved in mounting an imco 2 inch shorty on a b max drive

Don't know where your at but I would get ahold of Ron at JR marine in e lake Ohio. He is the man when it comes to b-max drives

I ran both the B Max shorty and Imco shorty on my B Max's in my old boat. Seem to recall that the Imco lower had to adapt to a larger output shaft in the B Max upper, may have had to but otherwise is a straight bolt in.

FYI I changed from the B Max shorty to the Imco due to the fact that the quality and design of the B Max sucked. The B Max lower hydrodynamics was really bad getting on plane, prop cavitated horrible and the prop slip was almost 5% better with the Imco after 100 MPH. The B Max lower also had some core shift that placed the o ring at the very edge of the upper and would leak drive oil. I contacted the old owner of B Max Dean and he told me to pound sand. Mind you he told me to pound sand after I had bought like 4 drives, bunch of replacement gears etc. etc.

John Pfahl who is now the owner of The Bravo Shop redesigned the Bmax lowers a few years ago to correct the problems with them.

An Imco lower should be a direct bolt on to a Bmax, but call John to make sure on any specifics.

From what I'm hearing is that the vertical shaft has to be changed unless anyone knows anything different

I recall there being something I had to do to adapt the Imco lower to the B Max upper.... You might try calling Ron Gibbs at Bad Attitude Marine, He likely still has the many spare B Max parts that I was storing at his shop.... His phone is 928 669 8870. He has a lot of B Max experience and would likely be able to help you through this. He still services my old boat for the new owner and last I heard still has B Max's on it.

Yea hopefully my xr's last this summer imma start looking for some bmax r imco uppers

Slippy, you sent me a visitor message and I could not figure out how to reply.... The boat I had the B Max's on was a 33 Eliminator Daytona with 1,100's in it. The B Max uppers were near flawless for the 7 years I owned the boat, lost one upper gear set. I was very happy with the uppers and thought they performed pretty well for a boat that should have had 6's on it. Ron at Bad Attitude did all my drive maintenance to include the rebuilds. He should still have some of my spare parts I kept just in case.

Hope this helps.

You need to change vertical shaft to a bmax shaft.

Slippy0217,

what gear ratio are you running and what will you have when you bolt the Imco on? I thought the gear ratio of 1:35 was unattainable with a Bmax. Not sure could be wrong but that is what I thought I heard.