1993 115 hp Evinrude won't plane

T.hagen

Recruit
Joined
Jul 11, 2017
Messages
1
Hey guys I've posted on a couple sites and am still looking for help, I just bought my first bass boat and I'm having a problem with it getting on plane. It's a 1994 Nitro 170 DC Rick Clunn Edition with 115 hp Evinrude, I got a hell of a deal on it so I felt like it was time to pull the trigger. We've had it on the water twice now, both times having the same issue. We had the throttle full bore and it just kept plowing through the water. Eventually it did plane out, but not until it mulled through the water for a minute or two. I noticed that it would get up out of the water quicker if we'd put her in a turn, or if we started to catch a little chop in the water. It would also plane if one of us sat on the bow. We've had the ear muffs on it out of the water, and that engine will flat out run, great response, and sounds good. On the water the engine hangs up at 2500 rpm until it gets on plane, where it gets up to 4000 rpm, before settling back in around 3000. Carbs have been rebuilt and all new plugs. Compression test was also done, I'm not sure about a trickle down test. I have a raker 13.5 x 20 prop on it. I'm just wondering if you guys have any suggestions? I've read or been suggested a different prop, lowering the motor on the transom (mine is on the top holes), power pack issue, timing issue in the motor, or I have a prop cavitation. A guy on another forum said he had a similar problem with the same engine and said the pistons were eating rings. My father and I are both at a loss, he's owned multiple boats in his day, but they were all inboard ski boats, never an outboard with a 2 stroke. Thanks in advance!
 

oldboat1

Fleet Admiral
Joined
Apr 3, 2002
Messages
9,612
outside chance it's the hull -- water and water logged foam under the flooring.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,576
A 20" pitch prop is a lot for that motor. In theory dropping the pitch 2 inches will add 400 RPM to your max RPM. You may get more RPM since the motor will be more in the powerband as well., Of course, prop selection is mostly trial and error.

I would borrow or buy a 17" aluminum prop and try it out. You do need a spare prop anyway.
 

Chinewalker

Fleet Admiral
Joined
Aug 19, 2001
Messages
8,902
That motor should pop that boat on plane no problem at all. Something is going on with the motor - suspect ignition issue. I'd do a cylinder drop test while underway to see if you can localize it. Don't take any pleasure rides with it until you get it sorted out. If it's a fuel issue, you may cook a cylinder if it's running lean.
 
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