98 Evinrude 115spl has intemittent WOT power problems

[ChadJ55]

Hello everyone,<br />I really need some help with this one cause its killing me...<br />Like the title says, 98 Evin. 115spl is having intermittent problems reaching WOT and has power loss of about 1000 - 1500 RPM in the 2500 - 5300 rpm range. Below that it is ok. <br />What I've already tried-<br />Replaced plugs<br />Replaced fuel water separator<br />Run B-12 fuel treatment (new fuel anyways)<br />Tried pumping primer ball during problem- no change<br />Tried pushing in key- no change, just stalled after a bit<br /><br />I've searched the archives and found many, many similar posts but none with a real resolution. Here is some more background on the problem. By the way, compression is fine.<br /><br />Engine will usually (not always) run like a champ when cold for the first 15 - 20 minutes, then the problem shows itself.<br />The problem is often related to the plane angle of the boat- once it reaches plane, power comes back SOMETIMES.<br />Power sometimes comes back after hitting a big wave and shaking the boat up a bit.<br />On some occasions, it will be running fine all day, then I shut it down for 5 minutes, start back up and the problem is there again.<br />Sometimes after running at full throttle (with power loss) the power will just suddenly comeback and the boat takes off!<br /><br />When the problem is happening, the engine has a bit of a lower tone. I've ruled out fuel starvation by pumping the bulb but pushing the key in didn’t do much for me. The engine lurched for a split second before stalling and being flooded, but it was not an instant pick up by any means. I've thought maybe it could be a problem with a cylinder not firing, but it seems that it would run much rougher. The tone is lower, but it is not running rough when this happens. <br /><br />Sorry for the long post but I want to put EVERYTHING in here that is happening to give the clearest most accurate picture. Thanks so much for any help.<br /><br />-Chad

 

[ob]

Re: 98 Evinrude 115spl has intemittent WOT power problems

shot in the dark chad but try checking out lanyard kill switch.I had one that was making intermitent contact and the syptom was similar.If not that I'd look closer at carbretor mix adjustments.try different settings using 1/2 turn incriments on each to see what effect it has on performance.fine tuning of motors are unique to each boat ;ie prop and load applications.Good luck

 

[fshng4]

Re: 98 Evinrude 115spl has intemittent WOT power problems

Chad,<br /><br />As I have posted earlier I had a very similar problem with my 115hp Yamaha. The motor run fine one day and had a loss of power (just like you are discribing) the next day. Mine turned out to be a bad coil. I really could not distinguish the problem as being a miss (just like you said) but it was. When I took it to the dealer he told me one of the coils had no spark at all - he replaced it and it runs fine. You can test this yourself - go to your local automotive store and purchase (approximately $7) a sparkplug wire tester (the one that clips onto the sparkplug boot and grounds to the engine). Follow the instructions on the package and you should be able to see if you are getting spark to your plugs. - you will be able to see the spark jump the gap on the tester - you should have about 3/8" to 1/2" spark). Hope this helps.

 

[clanton]

Re: 98 Evinrude 115spl has intemittent WOT power problems

If it is a 60 degree engine, check power pack, sensor, coils.

 

[ChadJ55]

Re: 98 Evinrude 115spl has intemittent WOT power problems

fsng4, That sounds like what I was thinking might be the problem. I actually just went out on the boat after reading your post and tried, out of curiosity, while the engine was running correctly, I pulled the wire off one plug. The engine definitely ran differently than when it acts up. On only 3 cylinders it had very little power- less than when the problem occurs, and the engine felt and sounded diferently. I am not ruling out the chance of it being the coils or ignition related, but it still seems to be a mystery. Tried pushing the key in while running again (while it was acting up) and again, it did not make a difference till the last second when it lurched up to speed then died. All together it makes me more suspicious of the carbs.<br />If it is the power pack, 1)would it make sense that it would be intermittent, and 2) would it behave the same as if the plug was not firing at all (like it did when I pulled the wire off)?<br /><br />I really appreciate any input and the input I've already received. I am hoping to corect the problem by the weekend.<br /><br />Thanks-<br />Chad

 

[ChadJ55]

Re: 98 Evinrude 115spl has intemittent WOT power problems

BTW, does anyone have a cost estimate about how much a power pack costs and/or how much it typically costs to have my carburators checked out and fixed?<br /><br />Thanks!

 

[breezland]

Re: 98 Evinrude 115spl has intemittent WOT power problems

i have a 79 johnson 115 hp same exact problem. loss of power then surpirsingly surges of power. some trips i will putt around for a 1/2 hour then bamb off i go like a rocket. i have almost eliminated fuel starvation which seemed to be the likely problem. I have tired new fuel filter, new bladder & line, had carbs rebuilt and put new thermostats. It still acts up like u described. i noticed a chaffed wire coming off power pack i will be replacing it to see the result. i will let u know if that fixes it. By the way does anyone know how to replcce a wire coming from the power pack. do u melt the wax or waterver is in it and repack?

 

[Walker]

Re: 98 Evinrude 115spl has intemittent WOT power problems

Check to make sure your coils are grounded good. A bad ground will cause the problem you are having. Walker

 

[ob]

Re: 98 Evinrude 115spl has intemittent WOT power problems

lanyard kill switch is by far the easiest to eliminate as possible cause.switch sometimes makes intermittent contact and serves to ground the ignition system if your one of the almost no boaters who hooks lanyard to self while underway.

 

[ChadJ55]

Re: 98 Evinrude 115spl has intemittent WOT power problems

Its amazing how many people seem to have this problem. Its also amazing how varying the solutions are. I called my OB mechanic today and he seemed to think the carburators could be the problem but certainly did not sound as confident as I would hope. And at a cost estimate of close to $400 to MAYBE fix my problem, I am not yet ready to rule out ignition problems.<br /><br />OB, I do not typically attach the lanyard kill switch to myself, but I will look to see if that could be the problem. I have never worked on my carbs before and think I want to leave those to someone less likely to screw something up than myself.<br /><br />Crabaholic- I am interested to hear that having your carbs done did not solve the problem. The issues we are experiencing seem very similar. Please let me know if fixing that wire corrects it for you. I am going to take a real close look at all of my ignition related parts, clean contacts, and try to get to the bottom of this. I am very skeptical about taking it to a mechanic at this point because it behaves ands misbehaves so randomly. I just KNOW that when I take it, the mechanic will not be able to duplicate the problem and I'll dump a bunch of expensive labor hours into nothing.<br /><br />Maybe a stupid question, but can someone confirm if there is in fact such a thing as weak spark? This would give me much more inspiration to dig deeper into the ignition. Because when I pulled the wire off one plug when the engine was running perfect, it DID NOT duplicate my problem. With the wire off, there was an obvious miss and far less power (than when the problem happens).<br /><br />Thank you all very much for your input.<br />-Chad

 

[BKool68]

Re: 98 Evinrude 115spl has intemittent WOT power problems

If you pull off a plug wire and the motor runs worse then that cylinder is making power. Did you try this with all cylinders? After running it with it struggling pull the plugs and see if one appears different from the others, clean or sooty, wetter or drier. I have had a plug wire ground out on the motor latch and cause a similar problem, running with the rear latches undone or hood off would stop the problem. I have a problem with water in my built in tank being sucked up and plugging a brand new fuel filter that causes it to bog on throttle but run at idle. I also had a problem with carbs I thought I rebuilt OK but did not get the high speed jets quite clean enough. Any of these could be your problem or it could be another, you just gotta be patient and keep trying or be willing to spend big bucks for someone elses time.

 

[my new fishmaster]

Re: 98 Evinrude 115spl has intemittent WOT power problems

Thats a newer motor I would rule out the carbs its got to be the fuel pressure. Get a diaphram kit for the fuel pump and install see if this helps.

 

[fshng4]

Re: 98 Evinrude 115spl has intemittent WOT power problems

Chad<br /><br />I posted to you earlier about my Yamaha 115TLRS as having a bad coil. My engine had run reat for the last 2 trips and then tonight it started cutting intermittenly at wide open throttle. Before I had the new coil put on the engine would bog down about 1500 to 5000 RPMs now it seems to idle fine (probably all day) and plane out fine but starts to cut out after running at WOT for about 1/4 mile. I can back it off and it seems to run ok but once I get it back to WOT it starts cutting out. If you find out anything or if I find a solution I'll post back.

 

[breezland]

Re: 98 Evinrude 115spl has intemittent WOT power problems

I purchased a new power pak last night and will install tonight it got too dark to install last night. that will eliminate the the chaffed wire as the culprit. If that does not make a difference i guess i'll state lessons on fuel pumps. As far as my carbs are concerned i was having fuel pour out of them. I knew enough not to mess with them. i really do not know what they did because the mechanic must of felt sorry for me for the all the problems i had and did not charge me i believe he just adjusted them and put new gaskets on it. i will know by tomorrow and will let u know.

 

[fshng4]

Re: 98 Evinrude 115spl has intemittent WOT power problems

I went to the lake early this morning while it was still dark. I started the engine to see if I could see any loose spark flying around under the motor cowling. I put on a pair of rubber gloves and while the motor was running I began lifting the boots off of each plug to check for spark. All looked ok until I got the the plug & boot of the new coil. I poped the boot off and i got nipped pretty good - enough that I dropped the boot onto the motor - it landed upside down with the plug opening towards the sky and I had quite a bit of spark on the back side of the boot. I shut down reattached the boot and tried removing it again (I do have a big red S on my forehead to) and I got the same results - shocked - dropped the boot and saw sparks from the back side of the boot. I shut down and I had just purchased a new boot the night before for my spare coil so I installed it. Started it up - pulled the boot off of the plug with no problem. Run her down the lake for several miles and it runs like a dream. Don't know quite yet if that is the problem but evidently the rubber boots insulation had broken down causing intermitten spark. I will keep you guys posted.

 

[breezland]

Re: 98 Evinrude 115spl has intemittent WOT power problems

to chadj55<br />for your inof the power pack for 79 johnson 115 cost me $75

 

[jegervais]

Re: 98 Evinrude 115spl has intemittent WOT power problems

Chad-<br /><br />The 1998 115 SPL is a 90 degree block, cross-flow V4. It uses a charge coil (in the stator assembly) to generate the ignition system operating voltage (150+ w/DVA meter). The timer base generates the voltage signal (about 1/2 w/DVA meter) that "tells" the pack when to fire each cylinder. The powerpack stores the high voltage in a charge capacitor until it receives the signal from the timer base and then releases the voltage to the ignition coil. The ignition coil serves as a step-up transformer.<br /><br />The charge coil, sensor coils (timer base) and igntion coils all have there own voltage output and resistance specifications - the powerpack only has a voltage output spec. If you don't already have a factory service manual, get one.<br /><br />Run the tests on a "stone cold" engine. This will give you a base line to work from (you said the engine runs fine when cold). Run the engine until it warms up and the problem returns, at that point find a place where you can run those tests again while everything is hot. If you find any significant change to the first test results, replace the offending component. If you don't find a significant change in voltage outputs or resistance, I would suggest indexing the flywheel and check timing on all 4 cylinders when the problem occurs. In doing this, you're looking for what we call a "double-firing" condition. When you check #1, you should only see the timing mark for #1. If for instance you saw a "ghost" image of one of the other cylinders, that would indicate the powerpack is double firing and needs replacement.<br /><br />I know this is kind of long, so if you need any points clarified, ask.<br /><br />-John

 

[BKool68]

Re: 98 Evinrude 115spl has intemittent WOT power problems

If that boot was a bottom cylinder it was gounding out to your motor latch. A very common problem for me at least. Keep spare boots onboard and be very careful removing the cover. Whenever I loose power I undo my rear latches to see if it helps. I have also covered them with tape to keep them from conducting.

 

[ChadJ55]

Re: 98 Evinrude 115spl has intemittent WOT power problems

Very interesting about the boot and insulation problems. I will surely take a close look at all of my ignition components. I have yet to purchase a manual for the engine but think I will be doing so very soon.<br />John, thank you very much for the explanation and diagnostics for the power pack and coils. The mroe I am hearing, the more suspicious I become of the power pack. From what youv'e explained, this "double firing" would make a lot of sense. Because it really does not feel like I am loosing a cylinder, but more like it is not firing how it should and it just out of sync.<br />Crabahalic, thanks for the update and cost info for the power pack. I have heard of some rpetty outrageous prices for thos things but that soudns reasonable. Not sure how much more expensive it would be for a newer motor, but I was able to locate a few on ebay as someone suggested. I am very anxious to get the boat back into the water to run some of these tests.<br />If my problem is, in fact, the power pack, is it a very difficult part to replace?<br /><br />Thank you all again so much.

 

[ChadJ55]

Re: 98 Evinrude 115spl has intemittent WOT power problems

Very interesting about the boot and insulation problems. I will surely take a close look at all of my ignition components. I have yet to purchase a manual for the engine but think I will be doing so very soon.<br />John, thank you very much for the explanation and diagnostics for the power pack and coils. The mroe I am hearing, the more suspicious I become of the power pack. From what youv'e explained, this "double firing" would make a lot of sense. Because it really does not feel like I am loosing a cylinder, but more like it is not firing how it should and it just out of sync.<br />Crabahalic, thanks for the update and cost info for the power pack. I have heard of some rpetty outrageous prices for thos things but that soudns reasonable. Not sure how much more expensive it would be for a newer motor, but I was able to locate a few on ebay as someone suggested. I am very anxious to get the boat back into the water to run some of these tests.<br />If my problem is, in fact, the power pack, is it a very difficult part to replace?<br /><br />Thank you all again so much.