Re: Exhaust Housing Size & Carb Orifices

[Don]

Well, these engines rely a great deal on exhaust tuning when it comes to hp ratings. So, it might just be that the exhaust tuning in a short shaft engine is slightly different requiring a slight jet change. The engineers really went too far in this regard, I seem to recall that some of the 50hp blocks had a slight spray of water introduced into the exhaust chamber that helped develop power. I can’t remember if WOT timing settings were different for the two hp models also, perhaps not… The sync and link procedures are ridiculous, a 10 step procedure that is a pain and "over engineered". The same engineers that developed the sync procedures for later model 6-8hps must have worked on the 40-50 models as well.
The only benefit of these over the earlier models are the split lower motor cover, nice trim unit, and more robust gearcase (except for the CPS shift rod cover)….