Evinrude 115 SPL over rev bad, please help

I'm scared to death I've garbaged a power head.<br /><br />Put a new water pump in for the first time yesterday and put the l/u back on this morning. Followed the OMC manual to the letter. <br /><br />When I took the prop off, there was no keeper, just a cotter pin in the prop nut, and the prop nut was very loose, it took all of about 2 in-lbs to loosen. This worried me! When I reinstalled, I tightened to about 20-25 ft-lbs and prop still spun freely.<br /><br />Took a few tries to get the splines on the driveshaft to seat in the crank, but it eventually went in far enough for me to seat two of the l/u retaining bolts, stb side forward and prt side aft, then the aft bolt under the trim tab. Tightened 'em up in rotation. Never felt any resistance or anything that seemed odd or like anything was being forced. Connected shift linkage up on the first try--use a long pair of hemostats, they worked great. Tested shifting, shifted into fwd and hand-turned prop (wires off plugs) verified fly wheel turned clockwise. Shifted back to neutral, prop spun freely. Connected plug wires and tried to start. Nearly fired first attempt. Fired hard on second attempt and sprayed gunk all over garage door. Started on third attempt and TOOK OFF! cut it ASAP, saw RPM needle stuck on 5000. Examined linkages for a screwdriver or something I may have left in there, everything looked fine. Started again, and it TOOK OFF! Killed it again, maybe in time, I don't know.<br /><br />Could turning the prop (fwd) to verify the clockwise spin of fly wheel done something?<br /><br /><sigh>

Re: Evinrude 115 SPL over rev bad, please help

Hi StAugVol<br /><br />Hopefully you are alright. I´v heard theese 90deg V4´s can take a lot of rpm´s ( up to 8500 !!! )and it was only short time. Check to see that the butterflyes close totally when trottle is in iddle position. I am sure you will find something is not right. But is sure scares one !!!

Re: Evinrude 115 SPL over rev bad, please help

Youll be fine. Something has the throttle linkage held open. Turning the prop by hand should have no effect on rpm. Concentrate on the sync-n-link and itll be good to go. make sure the linkages are all at the idle position. <br /><br />Good luck!

Re: Evinrude 115 SPL over rev bad, please help

This manual does not number the cylinders. It gives firing order 1-2-3-4, but not one iota of which is one or four. At least, I've yet to see it on about, oh, four readings now... Would you guys know?<br /><br />Took the cover off the air flow housing, the four butterflies are shut all the way in neutral, fwd idle, and reverse idle. They open all the way as the throttle is opened to WOT in fwd, but only open a quarter inch in rev WOT. Is that normal?<br /><br />Do I dare run the engine with the cover off so I can observe the butterflies? I do this on mowers and weedeaters, and a couple old trucks, but outboards, well, like Sgt. Shultz, "I know nothing..."<br /><br />Thanks again

Re: Evinrude 115 SPL over rev bad, please help

David - I doubt that you have hurt your motor. It is not a good idea to run thos much over 2000 rpm out of the water. I also don't think changing the water pump caused the runaway. Running with the cover off is OK and what you normally do when checking this & that.

Re: Evinrude 115 SPL over rev bad, please help

Thanks SoLittle, <br /><br />I only idle on the hose. When I say cover, I don't mean the cowling, I mean the cover to the air intake, that exposes the carbeurator butterflies. <br /><br />I'm buffaloed on the runaway condition. TDC wasn't disturbed, so the timing sync test shouldn't be necessary, should it? There's a Throttle valve Sync procedure, but I'm hesitant to mess with it yet. What about a fuel supply issue? Seems like the bulb wouldn't pump as tight as it used to. I checked up inside the exhaust tube before putting the foot back on and it was clear, could a blockage or badly seated gasket on the exhaust housing do this?<br /><br />Stumped!

Re: Evinrude 115 SPL over rev bad, please help

StAug,<br /><br />The throttle plates sound like they are working right. It won't open them nearly as much in reverse.<br /><br />You must be getting air into the engine somewhee (around) the throttle plates.<br /><br />Did you knock off one or more of the little vacuum lines that go to the carbs. when you you were fishing around in there working on the shift linkage?

Re: Evinrude 115 SPL over rev bad, please help

DJohns,<br /><br />I don't think I did. I checked all the inbound fuel lines and their connectors at the bottom of the carb. I think I know the vacuum lines you speak of, there was a small one ran all the way under the carb right next to the linkage.<br /><br />What I've thought of and forgot to add is the l/u was stuck. I was afraid it was a bad seize at the crank/drive shaft, but it came off after only a little banging. There were some pretty substantial licks, though. Used a 5 lb mallet on a block of wood, one flang then the other. Where could that hammering have opened up an air hole? <br /><br />When you take off the air intake cover, those butterflies are the throttle, and not part of the choke? Pushing the key when starting I hear the customary sound of the prime. I got real courageous and fired it twice more, no change.<br /><br />You know, NASA could teach us a thing or two about firing a motor at full throttle! Take the gallium fueled lunar lander, for example!

Re: Evinrude 115 SPL over rev bad, please help

Hi Again StAugVol<br /><br />I dont think your motor has choke butterflies, but a small priming pump instead. You should be able to see throttle butterflies. Take a clouse look, they dont have to open much, when motor isnt under load. If you in first did forget to remove shift rod when trying to remove l/u, you maybe could have bent some of throttle mechanism out of shape, opening throttle just a little bit - maybee enough to start the take off - what do I know try to check carefully.

Re: Evinrude 115 SPL over rev bad, please help

Hey, really appreciate everyone's help.<br /><br />Dane, you're right, naturally. I have a choke solenoid that squirts in some fuel. Didn't know if there were butterflies to go along with it.<br /><br />Should I try to start the motor with the air silencer cover off to see what the butterflies are doing?<br /><br />I examined my throttle linkage and in neutral, fwd, and rev idle positions I can hear the butterflies snap shut if I lift and release the throttle cam follower.

Re: Evinrude 115 SPL over rev bad, please help

I am no outboard mechanic by any means but I have had the same problem with a 2 cycle dirt bike engine...a few times as a matter of fact.once I had a tiny air leak around the reed cage, once I had sprayed carb cleaner in the throat & got some kind of vapor lock on the slide & another time I got in a hurry & installed the slide upside down hehe...real surprised that I had to push her off & even more surprised when that YZ lit wide open.

Re: Evinrude 115 SPL over rev bad, please help

I've just come in from checking out my carb again, and guess what I found? A screw! A quarter inch long flat head was stuck under the port side, upper, butterfly, holding it up a little! The head is identical to those on the fuel pump, but all six of those are there. Looked everywhere for an empty hole but can't find one. Where could it have come from?<br />If this is the problem and not another symptom, looks like the winner is DHadley with "something is holding the throttle linkage open".<br /><br />I'll let ya know

Re: Evinrude 115 SPL over rev bad, please help

Glad you found it before it went further. That would be a mess!<br /><br />Good job!

Re: Evinrude 115 SPL over rev bad, please help

Where could it have come from? Could it have entered the carb from outside the air intake? Based on my current level of experience, I think it's a long shot it came from outside; wouldn't it have more than likely come from inside the carb and then fallen forward when the motor was tilted for travel? Then again, hitting a wake at full speed could bounce a screw around pretty easily...<br /><br />What do ya'll think?

Re: Evinrude 115 SPL over rev bad, please help

Glad you found it, I had a similar excursion. After re-installing my powerhead and lower unit I was out for a test drive in a very crowded party beach oggleing the bikinis when my motor stuck in reverse and wouldn't come out. I had to drift over to an empty slot on the beach and pulled my cover and started looking for what I might have screwed up. After considerable squinting and searching I spied the female end of a 10mm socket tucked neatly under the shift rod cam holding it in reverse. I had been wondering where that socket had got to.

Re: Evinrude 115 SPL over rev bad, please help

Make sure it's not one of the screws that hold the throttle butterfly on. Just peak down in the carb and check it out.

Re: Evinrude 115 SPL over rev bad, please help

Tested on the hose and in a tank this evening and she's ok, runs just fine, shifts fine, must have really needed the water pump, pressure from the tell tale is about 40% higher. Still buffaloed on where the screw could have come from. Checked every where, found an empty hole on the bracket below the flywheel where there were screws matching the culprit's head. Also a few empty holes on different places on the block and heads, but only one looked like it's ever had anything in it. Could tell much about the one under the flywheel. I'm gonna run her on the water tomorrow and see how we do at WOT and between.<br /><br />Everyone, Thanks so much for the assistance. As I learn more, I'll be sure to give back what's been so freely given.<br /><br />Is this a great country, or what!

Re: Evinrude 115 SPL over rev bad, please help

Running like a scalded dawg!<br /><br />Next up: Thermostats, that pesky fuel gauge, and nav lights!<br /><br />Thanks again and happy Easter