I have a 1987 Mariner 100hp jet motor and when I run it it gets up to 3800 rpm’s but doesn’t move any faster than 5mph or so, what could be a possible fix for this? It used to run almost 30mph at 3800 rpm’s and I took it to a local mechanic when it was having fuel issues and he’s replaced fuel lines, carb gaskets and since I’ve gotten it back it hasn’t ran right. I’ve put a brand new key way in the impeller and made sure the gap between the impeller and housing was right because that was a suggested issue of why it wasn’t running right. If you have any suggestions as to what could fix this I will take any help I can get!
