Help 1996ish Evinrude 115hp running problem???

[adm1476]

Ok here is what is wrong and what I have done so far. The problem is it runs like a cylider or 2 is coming in and out. Like intermittent spark. I will idle and push my boat about 20 or so but it surges anything beyond that.The more throttle you try to give it the worse it runs. I have checked compression, good. I put on a new cdi, rebuilt both carbs, and put 2 new coils on it. I also switched the new coils around to see if it would make a difference, but it still runs the same. I also changed the spark plugs just in case 1 of them was bad. No change. Help need suggestions.

 

[Roj115]

It sounds like you've got an intermittent spark problem on at least one of the cylinders, and my guess is it's probably just one. To troubleshoot, try disconnecting the spark plug leads one of the time and running the engine with the one lead disconnected. If disconnecting one of the spark plug leads does not change the way the motor runs then you'll know that is the bad cylinder or one of the bad cylinders. You said you changed two of the coils and then tried switching the positions of the new coils with no effect. What if the two coils you replaced were both good and the bad one or ones are still in there? Then switching the positions around would not make any difference. It would just change the location of whatever cylinder or cylinders are not firing or are firing intermittently. In other words, the problem still exists but the location of the problem is moving around depending on where you moved the bad coil or coils to. Try switching out the two coils that you kept with the two coils that you switched out and see if that has any effect.

Also, you said you've changed out the spark plugs and half the coils but you haven't investigated the link in between those two things which are the spark plug leads.

Try isolating the bad cylinder first by doing the thing I first suggested. Once you've isolated the cylinder then isolate the bad component by trying replacement components on that cylinder. Work from the spark plugs and then move on up the chain. Since you've already changed spark plugs out then first try replacing the spark plug lead or at least cleaning up the connections on the lead and then testing the lead for continuity. If that hasn't solved the issue then try replacing the coil on the known bad/intermittent cylinder. I think by the time you've done this you will have solved the problem because I highly doubt the problem exists higher up the chain which would be the power pack or the stator / timer assembly.

 

[jakedaawg]

Try running with the cover off. Also please post model number.

 

[adm1476]

Ok I forgot to mention that I also have replaced the spark plug wires. Here is the model number E115TSXEUA. Should be 1996 I believe.
Roj115 I am going to try what you suggested this morning and I will post my findings. Thanks!

 

[adm1476]

I ran the engine with the cover off no difference at all. I also tried removing 1 wire at a time with the engine running, and very slight if any change in the running was noted. I also used a spark tester to check for spark on all 4 cylinders and they all are sparking but it does not look consistent to me. Also i removed the plugs just to inspect and all were very wet. It seems like the engine is just not firing consistently at the correct times????

 

[racerone]

That is in fact a 97 model.------The first step is a compression test.----Post your numbers.

 

[adm1476]

Compression is 120 on top 2 cyl and 125 on bottom 2 cyl

 

[adm1476]

Just an FYI I am an auto technician. So I am familiar with the basic stuff when dealing with boats. Just not a marine mechanic. Compression is within normal limits. So all that is left at this point should be the timer base of the stator?? Is this correct?

 

[oldboat1]

Rule out fuel issues (water), particularly if a permanent tank. Can siphon up some from the tank bottom and let it settle in a glass jar (fuel will float on top of any water -- separation will be visible.)

 

[adm1476]

The tank was completely dry when I put new gas in it 2 days ago.

 

[racerone]

Surging is a FUEL PROBLEM !!!

 

[adm1476]

I will pull some fuel out and see what happens. I guess it is possible that I got some bad gas at the station. I will let you know.

 

[adm1476]

Ok so here is the days story. I used a spare 6 gallon tank that I had with all fresh fuel. It did run a little better but overall the same problem. It seems like there is spark coming in and out. I can have it idling on the hose on the trailer and it jump from 1500 rpms to 2000 rpms. It will not idle consistently it is all over the place. I try to set it at 1000-1200 it will drop to 700 and stalling then I adjust it up and it is around 1800-2000 and still jumping around. High or low rpms still jumps around like a cylinder or 2 is coming in and out. I took it out for a ride , and holy crap it is using a ton of fuel. I bet I went no more than 2 or 2.5 miles and it used almost 5 gallons of fuel. It also jumps around while moving also. Help!!! this thing is really starting to **** me off now. lol

 

[jakedaawg]

How are you adjusting the idle? Do you have a manual? some of the screws that look like idle adjustments are actually timing stops.

Also, Have you checked to see if you sheared the flywheel key? If it ever came to a "dynamic halt" this is possible.

It also helps to have an open air gap spark checker thate lets you test all four at once, This lets you see the alternating fire of ecah cylinder.

 

[adm1476]

I do not have the manual however I have adjusted many on these motors before without any problems. I started out by just using the cable but by now I have adjusted everything to try to improve its situation. I will pull the flywheel and check the key. I do not have a spark tester that I can test all 4 at once.

 

[oldboat1]

Believe your '97 has fuel pump. Check for cracks in hoses and leaks around all fuel hose connections -- fuel hoses, and hose to manifold assembly. Then check the fuel pump diaphragm for tears or holes. If in doubt, replace it (should be flexible as well as complete). Maybe you've already done this.

 

[adm1476]

I have inspected the fuel lines etc for cracks. I have not looked at the fuel pump diaphragm. But judging by how much fuel it is using I would say the pump is working fine. I went less than 2 miles and burned almost 5 gallons of fuel. ???

 

[oldboat1]

Fuel pumps and carbs are easy to pull off and disassemble/inspect/reinspect/rebuild -- pump diaphragm, carb floats and float valve assemblies (float, needle, washer, seat, clip). A damaged jet is possible.

In lieu of a manual, iBoats site can help for post-'68 parts diagrams, likewise BRP: http://epc.brp.com/SiteMods/BRP_Public/BRP_Public_Login.aspx?ReturnUrl=/Index.aspx

 

[hidef]

It sounds like you have an issue with the power pack. Have you determined that you have clean spark on all four cylinders? If the engine will not exceed 2800 RPM it is stuck in slow mode. You might have a bad sensor or the power pack is bad. Disconnecting the plug with the tan wires running into the power pack will help determine where the issue is. Also take a look at the CDI troubleshooting guide the link is in my signature.

 

[adm1476]

The CDI is new, however I will disconnect the tan wire and see what happens. I have the troubleshooting guide because it comes with the new CDI. I just ruled it out since it was new but anything is possible. It does tach over 2800rpms I have seen it get to 5400 but it was surging badly. Most of the time it will not go over 4000rpms