Johnson 9.9 four stroke performance upgrade?

[BIGGUN]

I just got a Johnson 9.9 four stroke engine. It was made in August 1997, so I assume it it a '97 not a '98.

I was wondering what if anything could be done to get the most performance out of it as possible. Are there any carb upgrades or exhaust mods? Any timing changes? I have it on an aluminum 17' center console so it moves it kind of slowly. Any increase at all would be great.

Thanks,
Kevin

 

[CATransplant]

Re: Johnson 9.9 four stroke performance upgrade?

I'm not surprised it moves slowly on a 17' center console aluminum boat. What's the maximum horsepower rating for that boat? 40? 60?

There's nothing you can do to that outboard that will make it move that size of boat along much faster. Your best bet is going to be to get an engine that's close to the rating for your boat. The 9.9 might make a good kicker motor for it, though.

 

[BIGGUN]

Re: Johnson 9.9 four stroke performance upgrade?

I'm limited on the lakes I fish. Most are 20HP but one is 9.9

I just want to make sure I'm getting all that I can out of it.

Thanks,
Kevin Miller

 

[CATransplant]

Re: Johnson 9.9 four stroke performance upgrade?

If your 9.9 is running well, then that's about it. The thing is that if the outboard isn't powerful enough to plane your boat, and the 9.9 isn't, then a little more power isn't going to do much. You'll still be plowing through the water.

I'm not sure what horsepower would be needed to plane your boat, but if you're restricted to 9.9 on a lake, then you're not going to go fast.

Here's what I do: I troll between fishing spots. It's amazing how many new spots I've found dragging a crankbait behind my boat on my way from one side of the lake to the other.

Lakes with an under 10hp limit have that limit so that folks won't be speeding around the lake. Usually, they're small lakes and are used for a variety of uses. I like lakes like that. The guys with the big bass boats don't bother with them, so there's more fish for me.

 

[BIGGUN]

Re: Johnson 9.9 four stroke performance upgrade?

Right now I'm going about 7 MPH. The motor is running at 3900 RPM. What is the operating range on a four stroke? should my RPM be higher? Do you think I need to reprop?

Thanks,
Kevin