SEI V6 Gearcases not compatible with modern engines

[jeffgaleabaco]

About a year ago I installed and SEI 300 series gearcase on a 2006 150hp.
Johnson. It originally had a magnum gearcase. After about 200 hours the pinion gear failed and destroyed the gearcase. SEI will not warranty it because their gearcases are only compatible with engines built before the magnum and lightning gearcases came out. This was somewhere around 2000.
Essentially their gearcases will not work on engines built in the last 11 years.
When I ordered it I did not read closely enough to where it says their gearcases will fit on "most" evinrude/johnson engines. Buyer beware.
My question is why? I don't understand. The gear ratio is slightly different but once you put in a compatible upper drive shaft, if a motor has the same horse power and is turning at the same RPMs why does it matter? Theoretically you could run it off an electric motor if you wanted to. Counter
rotating gearcases have different gear ratios and run off the same engine. I have put older style gearcases on newer engines and vice versa many many times and not had a problem. Please explain.
Thanks, Jeff

[admin]

Your particular model number requires a Magnum gear case, and we only support stock applications with our products. Why exactly they do that I am not sure, it could be that your motor has a different torque curve, is designed for performance boats, or is maybe underrated horsepower wise. Either way, the OE Manufacturer decided against installing their 306 equivilent and going with their heavyier duty unit. There is no doubt that the Magnum case is stronger so we wouldn't recommend nor warrant our drive for that application. I am not sure where you ordered it from, but our website list to please call with your model number for application assistance, and if ordering by phone we will double check your model number to be certain that you get the proper product for your motor. In your case, we would have recommended going back together with an OE lower since we do not make that style lower at this time.

And to clear up the misconception that our unit will not work past 2000, it is still being used on some current production motors.

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