1992 Johnson V4 Power Problem

[dustyrector]

I'm pretty new to boating and I just bought a 1992 17.5" Cajun fish-n-ski with a 1992 Johnson V4 outboard engine. We have taken the boat out a couple of times and the problem is that the boat has really insufficient power when "taking off" from "0". The boat really has a hard time getting going, but once it planes out, it runs great. Sometimes, it will not get the acceleration needed to plane out at all, and acts like it may stall. Once planed out at W.O.T., it runs at around 5000rpm. I put new plugs in the engine, and I thought I might try to clean the fuel filter, but I couldn't get to it. I have also tried running with the motor tilted to different angles. After the new plugs, it still has exactly the same symptoms.<br /><br />Can someone help me? Thanks a million!

 

[12Footer]

Re: 1992 Johnson V4 Power Problem

The fuel filter really is the next logical thing to look at. Check the tank for water at the bottom of it.<br />when you pump the primer, does it stiffen-up? Does gas leak from the carbs when you pump it?

 

[wilde1j]

Re: 1992 Johnson V4 Power Problem

Most of the OMC V4's want to run 5500 to 6000 RPM WOT. Once you are reasonably certain the engine is producing it's max power (I would do a decarbonize unless you know it was recently done), I would consider reducing prop pitch by at least 3". This will give better acceleration, probably better top speed, and a much happier motor. OMC dealers sell a product called Carbon Guard, which I would recommend regular use of after you do the decarb routine.

 

[dustyrector]

Re: 1992 Johnson V4 Power Problem

What is a de-carb?

 

[Bear]

Re: 1992 Johnson V4 Power Problem

It is...<br /> http://marinemechanic.com/site/page95.html <br />

 

[Dhadley]

Re: 1992 Johnson V4 Power Problem

I would agree. Get the RPM's up around 5800 with your average load. I would also try doing it with your existing prop by raising the motor (increase the X dimension), especially if you have a jackplate. That will reduce drag which increases RPM and speed and holeshot. <br /><br />Besides, it almost free and you can always put it back.<br /><br />Good luck!