Originally Posted by Chatts
Hi - I have a Quicksilver 380HD and a Mariner Marathon 25hp (1 year old). I have been told the 25hp is exactly the same as the 30hp and all you need to do is replace a restrictive gasket that is fitted between the carb and the engine with the one that is used on the 30hp.
Has anyone done this? Is it really this straight forward? Does it need rejetting?
Had 31mph out of it on my gps with 2 people so 5hp should make it even more fun...is a great package! Just need some of those transom wheels now.
If its a twin cylinder, single carb version, that looks just like a Tohatsu, then just take the carb of, remove the gasket that has a small slot in the inlet, buy a gasket for a 30hp and put it in. The carbs are just the same, no need to replace any jets. We do this all the time on some of our test engines, saves having 2 different engines!