outboard problems

[mjp]

I have a 1998 Johnson 115. The first time on the water was last Thursday. As usual the motor started right up and ran great for the first mile run. After that for the next 3-4 miles it started acting up-it starts and idles fine but at about 2000 rpm's it starts to cut out, spit and sputter and not pick up power. It will then pick up rpm's to 4500ish and run as usual for a short distance then act up again and loose power and speed, these changes are not gradual--the boat almost lunges when they uccure. I have ran a bottle of gum out in it and cleaned out the fuel filter by rinsing it out with clean gas and blowing it out with the compressor which didn't help much. Does anybody have any ideas to try short of taking it in to the shop.

[MadCatter]

I would suggest taking a look at the spark plugs, one of them might be bad or you might have a firing problem I recently had a spark plug go bad and it done basically the same thing .. worth a try

Dave

[Muddpuppy]

I've got an 82 Evinrude 25 horse that has about as much power as a set of oars. It seems to run on one cylinder at a cold start and intermitently once in a while but thats really noticeable. I just cant figure out where the power went. I've seen guys blow right by me when I'm at full throttle like I was rowing. Any suggestions before I might have it rebuilt from scratch or just buy a new motor ?? ?? :confused:

Thanks.

[roger23]

Have you checked your primer bulb. they dry out and crack then start sucking air.it is a cheap fix replacement ones don't seem to last long

[Hunt4Ever]

MPJ,

My buddy has the same motor and had the same problem. In his case it was a bad cylinder and was only running on one. The bad news is his estimate was $3,700 to fix it. The marina said when they took it apart they could tell the engine wasn't broken in with the correct oil and it never seated the rings. He was the second owner so there wasn't much help from Johnson.

I hope that's not it for you.

[BilgeRat]

Are all hoseclamps/clamps tight on all fuel line connections from the gas tank to the engine ? Have you done a compression check on the cylinders?

Ifyou still can't find the problem, try lockemans hardware with your questions http://www.lockemans.com/.

They are certified Johnson repair guys.

[BilgeRat]

Forgot to add following ?'s:

1. do you hear any warning sound comming from the dash, like a buzzing or beeping?

Engine could be overheating, I believe there is a overheating limiter that kicks in, drops rpms or shuts engine down when she is starting to overheat.

2. Is water comming out of the pee hole? When was last time you had the water impellar replaced? Also, thermostats could be a problem contributing to possible overheat?

3. Assuming you have vro, have you monitored the oil level in the oil tank to make sure it is going down? Could be the vro pump,(comb. fuel/oil injector)? I had my powerhead rebuilt last spring, new vro pump, the pump was defective and caused my rpms to act strangely. They replaced the defective pump.


That's all I can think off right now. Hope this helps out.

[Muddpuppy]

I just replaced the water pump last year and its not oil injected so it runs off pre-mix. I unfortunately am the second owner also and I hope its not a bad cylinder. The previous owner was an older man that my dad used to work with for many years so I think he took really good care of it but one can never be sure about that either. The motor is tiller arm steering and I dont have a dash board, its a 16 foot Blue-fin aluminum boat. The motor starts up great when cold but runs very rough then smooth then rough then smooth and back and forth for a few minutes like its loosing one cylinder back and forth like that. After it warms up it smooths out a little but then coming down from running top end for a while it shuts right down but starts right back up again and sometimes shuts down again but starts up again. I'm just gonna have to check a few things out here that you guys suggest and I hope I can solve this stupid problem cuz its to the point that I'd rather just use the darn thing for an anchor now and go get a new motor. But anyway I want to thank you all for all your help and advice and I'll let you know if I can solve anything with it. Thanks again fellas you've all be very helpful !! :D

[patcheroo]

I have a 75 hp. Mariner that had the same symptoms as you two guys. In my case I was losing a cylinder. It would run smooth then cut out then run smooth ect. The cause was a bad stater. Replaced it and solved the problem. Just a thought!....Patch

[DZtaxidermy]

That sounds like what my boat was doing just recently. It ended up being a bad ignition switch. I choke my engine with the switch. It kept choking the engine out randomly. A $30.00 fix.

[TONGA]

can you look down the carbs or injectors while it's running to see if it stops spraying gas when this happens? if it dose it may be a bad bad or cloged filter,or pump,,do you have a built in gas tank? if you do there is a ball check in the fitting at the tank that can cause this kind of problem!
also if you run it with the cover off at night time a lot of electrical problems will show themselves,youknow you will see sparks leaking from ,cracked plugs,coils,wires this wont always work but often times it is a easy way to trouble shoot electrical probs