Power Loss in 1977 115hp Johnson V4

[spiker_man]

Hi. The last time I had my 1976 Glastron with 1977 115hp Johnson V4 out it stuggled to accelerate to it's top speed. I'm thinking I may just need to replace the plugs. The symptoms are: started right up and was going good at about 25-30mph. When I would try to accelerate to a faster speed (up to 37-40 mph) though, it would struggle. You could hear the engine straining and wanting to go faster but was being held back by something. The day before it took the longest time to get started and out on the lake (about 10 minutes). I know I did a good job of flooding the engine while trying to get started. Once I did get started though I was running at top speed of about 37-40 mph. The next day is when I lost a lot of hp. Is it possible I really gunked up the spark plugs when I flooded the engine the day before? Any thoughts or suggestions would be greatly appreciated. Thanks. Paul

 

[DJ]

Re: Power Loss in 1977 115hp Johnson V4

Do the simple stuff first.

1. Does the boat have a built in fuel tank? If so, try running the engine on a known good portable tank.

2. If that checks out OK, you are dropping a cylinder. Look at the spark plugs. Are any real clean? If so, you are ingesting water.

3. If the plugs look OK, replace them with CHAMPIONS-ONLY.