Ready to give up on Johnson

[resteph]

Re: Ready to give up on Johnson

Yes, I know the compression is kinda low, but it did run ok the last time out. Next trip, it started fine, but would not plane out. Something happen between last trip to lake and the following trip after start up. With low compression, one would except it to be a little slow planeing out and top end not as fast as when new. I usually ran about 4000 rpm when traveling on the lake. I think something has broke or it has a electric problem. I hope to check the coils and do the timing light thing this weekend and try to see where or if I have a electric power problem. Thanks for all the imput

 

[ezeke]

Re: Ready to give up on Johnson

90 psi is good for your motor, so don't worry about the compression - it's good enouigh.

Are you sure that you are not overpropped? What boat are you running on and what is the pitch on your propeller?

Did you check the spark with an inductive timing light while running the boat?

 

[bonzoscott]

Re: Ready to give up on Johnson

I had a similar problem with an I/O. Turned out to be an intake leak. Spray some duck butter around and see if RPM changes. Quick and easy if nothing else.

 

[resteph]

Re: Ready to give up on Johnson

I have the engine on a 1985 Ranger 371 with a 24 pitch prop. Don't remember the name of prop, but until this problem occured, the boat would run fine. A little slow out of the hole, but run ok. I did try another pitch prop, still same problem. The engine sounds as if it is not revving up. It will hold about 2500 rpm and not a miss or anything that I can notice.

 

[nymack66]

Re: Ready to give up on Johnson

This engine has two power packs, Looks like one failed, a simple spark test will tell you which side, you can then swap the packs around and see if the issue follows it you can then determined which one it is.
For a spark test I recommend buying this and connect it up , On my V4 I have one connected to each cylinder and start the baby up you will be amaze to see how easy the troubleshooting is step is ! Plus it costs 1.99 ! My coffee is cost more
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=4424