3 year sleep, 1987 120hp runs sporadically (rev-die-rev-die)

[FasterE]

The engine sat for 2-3 years. I replaced battery, drained fuel lines and carb bowls. Oil injection is removed and and new fuel/oil mix (50:1) was added to the freshly cleaned tank.

Pumped bulb until hard. Began turning the engine over. Within 5 seconds, it started. I needed to bump the choke every 10 seconds for about one minute until it would idle unassisted. The idle was sporadic; sounded like rev-die-rev-die-rev-die-rev-die-rev etc... with a frequency of about one rev-die cycle per/second.

I stopped the engine and took the hood off. I removed the breather/carb cover (not sure if that's the correct name for it). There was a couple of teaspoons of oil (not fuel oil) inside the breather. I cleaned it out. Then I decided to try to restart it with the breather removed for a better look and it ran GREAT. It ran perfect for 15 minutes. I gave it an hour rest and restarted it and ran it for another 10 minutes. I reassembled it and restarted it for another 10 minutes a few hours later. Each time, it ran perfect.

Engine was tilted overnight.

The next day, it was back to running the way it was originally, rev-die-rev-die etc...

I tried squezing the bulb while it's idling to see if additional fuel pressure helped, but to no avail.

I have a video of the engine running, I can post somewhere if it would help.

Thanks kind folks,

FasterE

 

[tashasdaddy]

Re: 3 year sleep, 1987 120hp runs sporadically (rev-die-rev-die)

clean and rebuild the carbs. replace all fuel lines, tank to carb. see the TOP SECRET FILE.

 

[FasterE]

Re: 3 year sleep, 1987 120hp runs sporadically (rev-die-rev-die)

Figured that was the answer. Just wanted buy-in from the smart folks. Any recommendations for a retailer for the rebuild kits? Nevermind (don't bother). I'll shop around.
Thanks.
FasterE

 

[tashasdaddy]

Re: 3 year sleep, 1987 120hp runs sporadically (rev-die-rev-die)

simple as right here http://www.iboats.com/mall/partfind...gd_poid=109342&gd_row=85&**********=385723955

 

[FasterE]

Re: 3 year sleep, 1987 120hp runs sporadically (rev-die-rev-die)

Fantastic. I'll have 4 of these bad boys on the UPS truck before close of buisiness.

Thanx again!

FasterE.

 

[Dhadley]

Re: 3 year sleep, 1987 120hp runs sporadically (rev-die-rev-die)

A couple of things to keep n mind with your motor - if a carb body (or any carb body) is plugged and not letting fuel in then that cylinder isn't getting oil either. Pistons don't like that. Also it's OK to run that motor with the carb cover off at an idle but don't run it under a load with the cover off. Pistons don't like that either.

 

[FasterE]

Re: 3 year sleep, 1987 120hp runs sporadically (rev-die-rev-die)

That's an eye opening piece of information.

It never dawned on me for a second that running it for test purposes could be doing harm to the engine. I can't thank you guys enough for the valuable info.

I checked with my local Evinrude dealer to price the 4 carb kits; well let's just say the owner should change the name of his dealership to "Jesse James Outboards." I like to support the local guys, but at $127, I felt like I was being held-up on the plains; considering of course that I got them here at Iboats for $76 inc/UPS.

Thank you for taking your time to chime in gents'.

Errol

 

[FasterE]

Re: 3 year sleep, 1987 120hp runs sporadically (rev-die-rev-die)

The fish are jumpin' in the boat right now (well not mine cause I'm still not running - and presumably only until the oil slick hits.)

I carefully rebuilt the four carbs, cleaning all holes, flushing with carb cleaner and using little tiny brushes I bought from Harbor Freight for $1. After flushing, I rinsed with 50:1 fuel/oil mix and reassembled. I emptied the tank, rinsed, and added 5gal of fresh fuel/oil. Changed all fuel lines, clamps, and filters (with the below numbered exceptions) and it ran good for 20 minutes. Then it started with the rev-die-rev-die-rev-die thing same as before I rebuilt the carbs. Then it mysteriously ran good for 20 minutes and I shut it off thinking maybe it was OK. Got home from work the next day, cranked it up and it was back with the rev-die thing again. What ever happened, it happened while it was resting overnight. Here's what I did:

1) All fuel lines are 3/8" (and new) from tank to the manifold. [[For clarification, I'm calling this plastic piece (right beneath and inbetween the two bottom carbs) that has a 3/8" inlet and five 5/32" outlets to the carbs and choke a manifold.]] I did not change the 5 short pieces of 5/32" fuel line because I could not find any. No one seemed to have any. Since I couldn't replace them, I flushed them with carb cleaner and brushed the inside with a soft bristle pipe cleaner style brush. Rinsed with fuel/oil mix.

2) The clamps that were securing the 5/32" lines were "black tie wraps." I could not find any of these. I suppose being black means they're rated for a heat and fuel environment. Anyway, I reassembled using white tie wraps until the local Evinrude dealer restocks; at which time I will replace them.

3) The fuel pump assembly: (NOTE - the oil injection was diabled when I bought it used some years ago.) I took fuel pump assembly apart using a star tipped screw driver and carfully inspected it and all components. It looked clean. Nonetheless, I douched it with carb cleaner and rinsed with fuel/oil. I reassembled it, partially submerged it in fuel/oil and manually pumped it. Pumped fine. I blew in the crankcase presure inlet and seemed air tight. I'm not a mechanical engineer (actually, I'm an electrical engineer), but to my untrained eye, it appeared in working order.

4) The choke confused me a little bit. The design looks straight forward and seems to work (at least electrically - I can hear it clicking when I actuate it), except it has a Shrader valve and red lever petcock of some kind. This is not understood. Is this for injecting a product such as Seafoam? Is it just a convenience intlet for adding additives prior to stowage?

I have not replace any vacuum lines. I intend to check all of them today.

If you have any ideas, and are willing to give me your time to write, you have an avid reader.

Thanks,

Errol

 

[ezeke]

Re: 3 year sleep, 1987 120hp runs sporadically (rev-die-rev-die)

The main difference in the wraps is that the OE wraps are ramped to fit the hose as the others do a poor job and invite air leaks.

The primer solenoid is just a valve that allows pressurized fuel from the fuel pump to bypass the carburetors when the key is pushed in. If the red handle is aligned with the cylindrical base of the solenoid, the unit should function properly. The primer solenoid creates no fuel pressure on its own.

The schrader valve allows for efficient introduction of aerosol de-carbon treatment or fogging oil, using a $2.00 injector hose available from any BRP dealer - part 0763644.

 

[FasterE]

Re: 3 year sleep, 1987 120hp runs sporadically (rev-die-rev-die)

Ah yes, I see that the factory wraps are much better. Will get some next Tuesday.

I misunderstood the primer. I thought it created pressure. I see now where it doesn't. You got me to thinking that if it was stuck open, that it could flood the engine. So I clamped the primer outputs to block flow and restarted it. It ran smooth for 2 seconds and then back to the rev-die-rev-die sequence. probably not that.

I also need to mention something that I failed to mention earlier, that now seems significant. My ignorance caused me to possibly tell a half truth. When I said I rebuilt the carbs, I meant that I rebuilt the plastic parts. The part that houses the float, jets, etc... Behind the plastic parts is the metal housing with the butterfly valves that I was thinking was called a throttle body. Was I supposed to break those down and clean them as well?

I'm guessing the answer is yes and am feeling kind of dumb for not realizing that while I had it broke down the first time.

EW

 

[ab1]

Re: 3 year sleep, 1987 120hp runs sporadically (rev-die-rev-die)

The carbs are plastic, the metal housing with the butterfly valves is the throttle body....so I think you had it right the first time. And no, I wouldn't break that down and clean.

 

[ezeke]

Re: 3 year sleep, 1987 120hp runs sporadically (rev-die-rev-die)

You probably have an air leak somewhere in your system. You can put a little steady pressure on the primer bulb and watch for any leakage of fuel beween the bulb and the carburetors. Be sure that your carburetor gaskets are good and also airtight.

The air silencer gasket also needs to be tight on the looper engines.

 

[FasterE]

Re: 3 year sleep, 1987 120hp runs sporadically (rev-die-rev-die)

I took the carbs off again, checked for blockages, reassembled making sure everything was tight. got the new 5/32" lines from Evinrude late yesterday put them on using factory tie wraps. Everything tight.

Still the same. I'm beat. Seems we're out of ideas here so I guess I'm going to have to bite the bullet and bring it to the dealer and pay up.

Thanks for all your great ideas folks.

EW