1991 Evinrude 150 XP (E150SLEI) with constant alarm and won't go over 3000 rpms HELP!

[stephenpence]

I'm trying to get my dad's old skeeter back up and running.. He?s got a '91 Evinrude 150 XP (VE150SLEIE) on back and I've been trying to piece together the puzzle by reading posts.. But I?ve hit this dead end. I've rebuilt the carbs and the engine now fires up fine, idles fine, but i took her out for her second run (first run never got above 5mph... hence the carb rebuild) and she sounded strong except the constant alarm sounded. But once I let her loose on the open water she never planed out, or pushed past 3000-ish rpm's. I tried reaching back and pumping the bulb when i had it at WOT to see if it gave her a boost, but nothing noticeable changed. the bulb was pretty collapsed, but it sounds like that is normal when the engine is sucking in the fuel? I also noticed the tach was only working sporadically, but when it was working or not didn't affect the performance of the engine again. I tested the compression of the cylinders when it was cold, and not really having run for 4 years, and they were all around 75psi. (Ranged from 72-76) From what I?ve read, that's low, but I?m hoping it's come up now that she's been on the water and run. I know the fuel lines are getting brittle as i punctured the primer bulb when i primed the engine to trailer the boat. With the constant alarm sounding as soon as I?d started the motor, it can?t be overheating, so it?s either the fuel vacuum alarm, or my temp sensor is shot.
1st set of tests (Fuel Starvation):
Under the advice of emdsapmgr and Bonairll I concluded the most likely culprit was fuel starvation. To test this, I ran the newly replaced bulb into a gas can sitting beside me in the boat. This way I could pump the bulb as it ran, and I knew there was no vacuum/venting issues with the tank. The constant alarm sounded as soon as I put her in the water and tried to start her. (once on dry ground.. when the boat is dry, it doesn?t seem to sound). I got her to operating temp and opened her up to WOT and still nothing past 3k RPMs (10-15mph). I hand pumped the bulb as it ran until it was hard, and still no change. The alarm continued to sound. At one point.. after I?d stopped the engine and caught a few bass, I kicked the motor on to move spots and the alarm, miraculously, didn?t sound. So I kicked her up to WOT and still nothing.. no change.. pumped and primed the bulb til it was hard.. no change even with the alarm off. When I got in, I checked the plugs, and the #4 plug appears to be fouled. (black, covered in a light film of gunk) while the other 5 seem to be great (light redish brown and dry). I started the motor and connected a timing light to the wire for the #4 plug and it pulsed like the rest of the wires did, so I?m guessing it?s just the plug. I can?t believe that one cylinder missing could be killing the motor like this though.
So.. my step #2 is to pull the fuel filter and clean/replace it, replace the fouled plug, and check the timer base to make sure it isn?t hung up and that it?s moving freely. Any other thoughts? With the engine maxing out at 3k RPM?s, could it be stuck in SLOW mode? (I?m not entirely sure the symptoms of SLOW mode with this motor, from what I gather though it maxs out at 2-2.5k rpms.. not 3k.) Because if it WAS in slow mode, paired with the constant alarm, I would think maybe that it is a faulty temp sensor or a grounding issue. (the fact that the boat doesn?t pick up performance when the alarm is OFF doesn?t lend any credence to this theory). Thank you for coming along on this journey!! Any and all help is greatly appreciated! There are exactly ZERO boat mechanics within 300 miles of where I live, so you guys are truly life savers!

 

[stephenpence]

Re: 1991 Evinrude 150 XP (E150SLEI) with constant alarm and won't go over 3000 rpms H

Just bought a new fuel filter. I noticed the engine was sneezing last time i ran it.. leaning again to fuel restriction... but the only thing left between the sensor and the fuel source was the filter.. so i'll swap it out and see what happens. it had a considerable amount of gunk in it! The manual says NEVER use the metal airplane style hose clamps (that's what iv'e grown up calling them... the ones that tighen with a screwdriver) and only use the plastic squeeze style clamps... anyone have any input on that? true or false??

 

[BonairII]

Re: 1991 Evinrude 150 XP (E150SLEI) with constant alarm and won't go over 3000 rpms H

After re-reading the other thread....I'm thinking that the alarm may indeed be causing your motor to go into SLOW mode(assuming slow mode is part of your motor).

I'm certainly no expert on your motor(or any other for that matter), but I think I remember a thread where the OP had similar symptoms...and S.L.O.W was the culprit.

 

[hidef]

Re: 1991 Evinrude 150 XP (E150SLEI) with constant alarm and won't go over 3000 rpms H

I would say you are stuck in slow mode. If the overheat alarm is going off then you are in slow mode. Is it pumping water if it is you need to check the thermostats and you need to check the temp sensors. If you have a infrared thermometer you can check the cylinder temps when the alarm goes off if it reads 163 of higher you have cooling problems. If it reads 130-150 with the alarm going of you have sensor issue.

 

[stephenpence]

Re: 1991 Evinrude 150 XP (E150SLEI) with constant alarm and won't go over 3000 rpms H

the pump is definitely pumping water.. i have a solid stream coming out at all time. I'll go snag an infrared sensor to see if the engine is overheating. if it is, then i'll know it is the thermostats. otherwise it'll be the sensor. Would the motor still go into slow mode even when the alarm isn't sounding?? also, when i have it on the earmuffs, and the alarm isn't sounding, it'll go up to 5000 rpms no problem.
in another turn of events, i replaced the plug on the #4 cylinder, and when i pulled it after running it, it was damp and i was getting a fuel air mixture steam coming out of the hole. it could be that that cylinder was about to fire when i killed the engine, but seems more likely that something else is going on. i pulled every other plug wire while she ran and the motor stumbled on all of them but #4.. I'll check the grounding on the coil tonight.

 

[ponyman460]

Re: 1991 Evinrude 150 XP (E150SLEI) with constant alarm and won't go over 3000 rpms H

interesting....SLOW mode huh? time to do some reading on that.

 

[BonairII]

Re: 1991 Evinrude 150 XP (E150SLEI) with constant alarm and won't go over 3000 rpms H

i replaced the plug on the #4 cylinder, and when i pulled it after running it, it was damp and i was getting a fuel air mixture steam coming out of the hole. it could be that that cylinder was about to fire when i killed the engine, but seems more likely that something else is going on.

Steam? I wonder if you're getting water in cyl#4.

 

[stephenpence]

Re: 1991 Evinrude 150 XP (E150SLEI) with constant alarm and won't go over 3000 rpms H

that.. could be. I hope not. the plug isn't shiney clean like tends to happen when water is entering the cylinder. i think i may have mis-used the word steam possibly.. there was a mist coming out of the hole.. but i think it was all just fuel mixture.
So the changes i made today:
I swapped out the fuel filter and the plug on cyl #4.
now for the results of today's tests:
The alarm did not sound today. at all(well, aside from the initial chirp when i turned the key to start the motor) so as it looks right now.. the alarm was the fuel vacuum sensor sounding. So, no SLOW mode. I hoped that this newfound gasoline flow would make everything better, but it did not. the motor still acted the exact same.. except no sneezing. just the missing from cylinder #4. she still maxed out at 3k rpm's and 10-15mph.
The number 4 cylinder is not firing regularly. i attached the timing light and took off in the water.. very sporadic. my initial thought was the coil obviously, so i pulled it, and resistance tested it, and all of the resistances were well within tolerances... so i swapped it with the coil from the #6 cylinder. nothing changed.. the #4 cylinder is still mis firing. the #6 cylinder, however, is just fine. I'm hoping you guys have an answer for this that doesn't involve the pack. i did check the timer base, and it seems to be advancing with the throttle freely.
I'm not sure if this is anything... but on the drive home it occurred to me that i had forgotten to attach the hose to the lower air intake plenum when i rebuild the carbs. i'm not sure what this guy does.. but like i said, he attaches to the air intake before the carbs, and goes somewhere that i could not determine. does anybody know the use for this guy?? I'm praying that it's a vacuum hose that somehow determines the allowable rpms of the engine, and since it was sensing no increased airflow through the intake.. it was killing the throttle. (i know this is ridiculous.. but a man can dream ya?) Thoughts anyone??? i'm at a total loss!!

 

[rebuilt]

Re: 1991 Evinrude 150 XP (E150SLEI) with constant alarm and won't go over 3000 rpms H

I believe the hose your talkin about is just the excess fuel drain hose that takes raw fuel from the plastic intake silencer box and routes in down and away from the carbs. I think it just ends below the cowling to exit into the water. Anyway, on the screw type hose clamps, I use em when I don't have the cute little proprietary high dollar J/E factory plastic clamps. The down side is they rust up. Fuel injection hose clamps are better, they provide a more even clamping, but will eventually rust up too. I like to use small zip ties on the tiny lines leading directly to the carbs. The book says don't use zip ties either, but the fuel is under so little pressure, what's the diff? No leaks to date. I noticed you have a manual. Isn't there a test for the coil pack? On another thought...Just got over a similar prob with mine. My motor had sat up for a long time too. Put it in the water, ran like crap. Rebuilt the carbs, started great, ran fine on the muffs but kept fouling #3. (I've got a 3 cyl) not a 6 like you, but the point I'm trying to make will go regardless of engine size. Ohm tested all coils, fine, tested fire with spark tester, fine. Just could not believe it could be trash in the #3 carb, I had just rebuilt all 3. I pulled it down again, and it was a tiny piece of trash in the high speed orifice in the bottom of the bowl. Fuel pull would pull the trash up against the orifice hole on acceleration, then release it to fall back to the bottom of the bowl. By then, the plug was oil fouled and wouldn't run anyway. Recleaned high speed orifice and jet, put it back together, and that was the end of the flug fouling, low rpm situation. Hope this helps. Have you thought about swapping a carb to put in place of the cyl that keeps misfiring?

 

[stephenpence]

Re: 1991 Evinrude 150 XP (E150SLEI) with constant alarm and won't go over 3000 rpms H

dang, i knew it was too easy as re-connecting a hose haha... i traced it back, and it seems to end at the cowling like you said... it's easy enough to clean the high speed orifices.. i might as well give it a shot. My main question is why the#4 coil spot is bad. (since i can swap coils around, and the #4 cyl coil is always bad, it can't be the coils, but rather the actual place where the #4 cylinder is sitting. that, and can this one coil misfire shut the whole motor down like this? and with 3 carbs on a 6cyl, would 2 be mis-firing if a one carb was jammed up? i can pull the 3 plug and just make sure that it's not having problems too... that would be an easier fix! anyone else?? haha.. i'll take all the suggestions i can get!

 

[stephenpence]

Re: 1991 Evinrude 150 XP (E150SLEI) with constant alarm and won't go over 3000 rpms H

So in an effort to generate some more interest in my thread, I figured I’d clean it up a little and eliminate the problems I've solved in hopes that someone can point me to the way to solve the problems I haven’t.
The major symptom is that the motor will not rev past 3k RPM’s (10-15mph) at WOT in the water. She’ll wrap out to 5500 RPMs on the earmuffs, but not under load. The #4 cylinder plug was oil fouled, so in an attempt to fix that, I discovered that the signal to the #4 coil is faulty. I've swapped multiple coils with their respective plug wires into that spot, and the problem stays on the #4 cylinder regardless of the coil that’s in that position. Also, the tachometer is working sporadically. I have seen no difference in the performance of the motor when it is working vs. when it is not, but it is maybe a symptom, so I figured I’d list it!
So far I've:
Rebuilt the Carbs
Replaced the fuel filter
Replaced the primer bulb
Replaced the #4 cylinder spark plug
Made sure the timer base is rotating freely with the throttle
Hand pumped the primer bulb while running the motor at WOT – no change.

I’m not sure if the 3k RPM problem is completely tied to the cyl #4 problem. It seems to me that with 5 cylinders, the old girl should still be able to power up past 2500-3000 rpms.. but maybe I’m wrong in that assumption! (if someone has information about that.. let me know!!)

Well, I hope someone else has had this problem, and knows how to advise me. My next test will be putting the earmuffs back on and seeing if the cyl#4 problem persists with a cold power pack. (I've heard rumors that they act up when they’re hot more than when they’re cold.. worth a chance) but other than that… I’m up a creek fellas!! Help me out!

 

[stephenpence]

Re: 1991 Evinrude 150 XP (E150SLEI) with constant alarm and won't go over 3000 rpms H

Well, I tested the #4 cylinder spark with a cold power pack.. and It showed to spark with my timing light.. so I decided to test the compression to see if it had come up from when I pulled it out of storage…. After the tests.. I kicked the engine on and checked the #4 cylinder again.. sporadic. The kicker is that the engine was running far better the second time, with the #4 cyl misfiring… when it ran the first time on all cylinders.. it kinda sounded rough. Although, as oil fouled as the plug is in there.. I doubt if it was sparking at all…
The other bad news that came from lunch, is that the cylinders are all running low compression. Each one was between 72-78 psi. the fact that they’re ALL reduced by the same amount makes me think maybe it’s just carbon build up… but then again.. that’s why I waited to test it until after I’d run her a few times…. Thinking that the build up would free up. Does anyone else have experience with a whole engine that’s compression has dropped THIS much?? A moment of disclosure, my father was not big on regular maintenance.. and I seem to have inherited that trait. So I SERIOUSLY doubt this motor has been de-carbed in the 10+ years since he inherited it from my grandfather. I’m beginning to feel like I’m putting together a puzzle from all four different corners here.. I’m hoping a picture emerges. Feedback on the coil issue? Recommendations for de-carbing this motor?? Think a de-carb could solve this problem or am I likely looking at a larger issue (head gaskets, etc)?

 

[BonairII]

Re: 1991 Evinrude 150 XP (E150SLEI) with constant alarm and won't go over 3000 rpms H

The other bad news that came from lunch, is that the cylinders are all running low compression. Each one was between 72-78 psi. the fact that they’re ALL reduced by the same amount makes me think maybe it’s just carbon build up…

Might be a bad compression guage.

 

[stephenpence]

Re: 1991 Evinrude 150 XP (E150SLEI) with constant alarm and won't go over 3000 rpms H

I'll calibrate it tonight... it's my trusty snap-on gauge, so i'm wanting to believe it hasn't fallen out of calibration... but anything is possible. I'm going to use Deep-Creep tonight and de-carb the sucker if the gauge checks out...

 

[stephenpence]

Re: 1991 Evinrude 150 XP (E150SLEI) with constant alarm and won't go over 3000 rpms H

gauge checked out spot on... so my cylinders are REALLY at 72-78psi. i read up on de-carbing and my cylinders are now soaking in a deep creep. i'll take it out to the lake tomorrow and run some more through it... see what she tests out at when the cylinders are sparkling clean. I read up on the trigger coil (in the timer base i believe) and i'll test that once i figure out how. i also have a dva adapter coming in to check the power pack. I'm beginning to think the 3k rpm issue is 90% the lack of compression, but i haven't heard from anyone if the one cylinder misfire can hold an engine back THAT much... so it's pure supposition. if anyone has any insight i'd love to hear it, otherwise i guess it's wait until the de-carb has run its course.

 

[BonairII]

Re: 1991 Evinrude 150 XP (E150SLEI) with constant alarm and won't go over 3000 rpms H

Are you just going to soak with deep creep? Or are you going to run a gallon of "Seafoam decarb mix" thru the motor?

 

[stephenpence]

Re: 1991 Evinrude 150 XP (E150SLEI) with constant alarm and won't go over 3000 rpms H

my plan (which is very open to adjustment) was to soak it overnight, (i injected the seafoam in each plug hole, rotated the motor a few times, shot more in, spun, shot, spun, and shot a lot, and trimmed my motor horizontal). my plan was tomorrow morning, of after work, to blow out the exces, bolt her all back together, and take it to the lake with 3/4 gallon of gas mixed with a can of seafoam. i'll run it at full throttle for 15, let it set, and repeat. i'll still have a can of deep creep that i can use to spray in the carbs if i need too... whaddya think?

 

[BonairII]

Re: 1991 Evinrude 150 XP (E150SLEI) with constant alarm and won't go over 3000 rpms H

Sounds good.

As for getting a ton more compression after the decarb..................Hope for the best, but plan for the worst. Getting another 20+ psi is going to be a longshot IMO.

 

[stephenpence]

Re: 1991 Evinrude 150 XP (E150SLEI) with constant alarm and won't go over 3000 rpms H

yeah i was afraid of that. i'd settle for 10-15. i was hoping that maybe the rings were just stuck, and that this would free them up. i've heard of a cylinder dropping to 50 with a stuck ring. I guess beyond this, its a matter of pulling the heads off and seing what's going on in there to cause such low compression? i can't imagine both head gaskets going out over the last 2 winters.. the mystery continues...

 

[BonairII]

Re: 1991 Evinrude 150 XP (E150SLEI) with constant alarm and won't go over 3000 rpms H

Problem is that ALL of your cylinders are pretty low(and consistent). Doubtful all of your cylinders carboned up the exact same amount across the board.

Take it one step at a time. Once the verdict is in from the decarb, you'll have to decide how much/how far you want to go with the motor to get the compression up (maybe new head gaskets, rings etc)