Re: 155 evenrude commercial
There are some differences that may impact your decision to purchase, esp if you plan to use it on a recreational boat. It should have the normal VRO oil pump and the large 35 amp alternator-both good features. The standard commercial will have a different gear ratio, of 12:27, or it can have a large gearcase with a 15:28, depending on model. You will need to prop differently with these engines. That large gear ratio case takes 71 oz of oil, compared to the standard 33oz models. It takes different plugs, and there is no recommended constant high rpm plug. The engine is made to run on 75 octane, so the engines will be set and tagged with lower max timing settings on the airbox cover. It still makes 155 hp at 5000 rpm.
