Need some advice guys. I got a good scare Saturday.

[Theoutdoorsman]

Well, I did the most ignorant thing I could have done Saturday. I ran my fuel cell dry and the motor came to an abrupt halt. When I went to back to prime the bulb, I found it was sucked completely flat. After finally getting the bulb to prime again, the motor is now acting sluggish. Now, it's surging. It acts like it wants to go, but just can't get the rpm's up and hold them there. It drops back a little, say from 5000 down to 4500, and acts like it tries again and again and then again. Rpm's go up and down like a yo-yo. Just to rule out any possible internal problem, I checked the compression to rule out a possible internal problem. They read as follows:

#1- 100 psi
#2- 107 psi
#3- 100 psi
#4- 100 psi

To my relief, this is pretty close to what I had when I first checked compression after the rebuild was completed several months ago. All the plugs looked nice and wet when removed. Would I be right to assume the pick up screen is partially clogged inside the fuel cell? I've never cleaned it in the five or so years I've owned this boat, and it's hard telling WHEN it was last cleaned. I'm assuming this is where I need to start. Any opinions out there? I have an auxiliary tank I can test with, before removing the carbs or turning the first bolt for that matter. Having never removed the pick-up, I could sure use some advice on getting this thing out to clean it. I'd like to remove the tank, but I'd say the whole top cap would have to be removed to do it. Is it possible to clean the fuel cell without removing it? Ahhhh, where to start? Thanks in advance for any and all advice!!! ............ Alan

 

[Theoutdoorsman]

Re: Need some advice guys. I got a good scare Saturday.

I forgot to mention, the motor in question is a 1979 Evinrude 140 and it's always been hard to prime the system.

 

[dsinger]

Re: Need some advice guys. I got a good scare Saturday.

Sounds like you sucked up a load of crap. Clean your fuel pump screen and any filters you have past the tank and before the cards. You might also have plugged a jet or two but start with the simple stuff.

 

[kenmyfam]

Re: Need some advice guys. I got a good scare Saturday.

Clean out the entire fuel system and try again. Sounds like there is some crapola in there.

 

[iwombat]

Re: Need some advice guys. I got a good scare Saturday.

Probably vaccumed up all kinds of junk from the bottom corners of the tank. Running the motor dry isn't all that big a deal if it's not then stored dry afterwards.

 

[Joe Reeves]

Re: Need some advice guys. I got a good scare Saturday.

The fuel primer bulb going flat is the clue indicating a fuel restriction. Note that the fule pump must be operating great in order to draw that bulb flat.

The restriction could be a faulty outlet valve (engine side) in the fuel primer bulb..... that valve does come apart at times, reverses itself and results, in effect, somewhat of a shut off valve.

And then there's the anti siphon valve, as follows.

(Fuel Anti Siphon Valve)
(J. Reeves)

Many of the later OMC V/6 engines incorporate a fuel restriction warning via a vaccum device attached to the powerhead. If the engine overheats, or if you have a fuel restriction, the warning is the same.... a steady constant beep.

NOTE... Only the V/6 & V/8 engines have the above "Fuel Restriction Warning". The warning horn will not sound on the other models.

The fact that a engine is not overheating, but the warning horn sounds off with a constant steady beep, and that the rpms drop drastically would indicate that the engine is starving for fuel due to a fuel restriction. Check the built in fuel tank where the rubber fuel line attaches to the tank fitting. That fitting is in all probability a "Anti Siphon" valve which is notorious for sticking in a semi closed position. It will be aluminum, about 2" long, and the insides of it will consist of a spring, a ball, and a ball seat. If this valve exists, remove it, knock out those inner components which will convert it to a straight through fitting, then re-install it. Hopefully that cures the problem.

The above procedure will cure a restriction problem with the anti siphon valve as stated. BUT, it may also allow fuel to drain backwards to the fuel tank when the engine is not running (siphoning backwards) due to the fact that the carburetors/fuel pump etc are higher than the fuel tank. This condition is not an absolute as the valves in the fuel primer bulb usually prevent this backwards siphoning problem. However.... if this does take place, the cure would be to install a new anti siphon valve.

http://stores.ebay.com/Evinrude-Johnson-Outboard-Parts-etc?refid=store

 

[Dhadley]

Re: Need some advice guys. I got a good scare Saturday.

Ditto Joe. Being hard to prime indicates a restriction upstream of the fuel pump and most likely upstream of the bulb. Running the tank dry probably pulled enough crud into the anti-siphon valve to really plug it up. The bulb being sucked flat indicates the restriction is upstream of it. Again, most likely the anti-siphon valve. Or the actual pick up in the tank is plugged. Once you get the AS valve out / gutted you can (gently) blow back thru the pick up tube.

Might not hurt to take a look at your fuel filter at this time.

 

[Silvertip]

Re: Need some advice guys. I got a good scare Saturday.

This seems to be a good spot to remind users of the portable fuel tanks that the same thing happens with these only it involves bits of plastic left in the tank from drilling and molding operations. I can't help myself when I see a line of tanks at a marine store so I take a peak in a few and invariably find plastic debris. It has happened to me where this debris clogged the pickup. I was amazed at the amount of this stuff I found in the tank. The flat primer bulb was the clue and in fact, the fuel pump worked so well that the vacuum it created broke the screen loose on the pickup and plastic got as high as the primer bulb.

 

[Theoutdoorsman]

Re: Need some advice guys. I got a good scare Saturday.

Thanks for all the help guys. But why the variation in rpm's? And what is the most affective means of cleaning the fuel cell without removing it? Thanks again.......... ALAN

 

[kenmyfam]

Re: Need some advice guys. I got a good scare Saturday.

If the fuel line feed is erratic then you will be getting varying amounts of fuel getting through hence the varying rpm's

 

[kenmyfam]

Re: Need some advice guys. I got a good scare Saturday.

I would also be checking any and all screens and filters first.

 

[Theoutdoorsman]

Re: Need some advice guys. I got a good scare Saturday.

I would also be checking any and all screens and filters first.

I removed the pick-up and it was as clean as a pin. Too, someone already beat me to straight-lining it. I also double checked all my connections from the bulb to the pickup tube and blew through the lines while they were off. I even cut the ends off and reconnected everything just to make sure I didn't have any air leaks that could be causing the hard-to-prime issue. (It was never this hard until I installed the water separator prior to starting the rebuild). I found absolutely no loose connections. I also have an in-line filter installed between the pickup tube and water separator. Surprisingly enough, everything looked to in fine shape. One thing I know for certain is, there is no filter screen in the fuel pump. That's why I installed the in-line filter. The only connection that I'm not absolutely 100% certain about, is the female fuel line connector to the outboards male end connector. However, I can install the auxiliary tank and it primes within just a few pumps of the bulb. Is it normal for this thing to be this hard to prime with a water separator installed? Well, on to the problem I guess. Since I found nothing that appears to be causing the problem, is it time now to remove and clean the carbs? Or should I try the external tank first? Man this is frustrating me!!!........ :-(

 

[Theoutdoorsman]

Re: Need some advice guys. I got a good scare Saturday.

How probable is it that anything has gotten past the in-line filter and water separator? Both are brand new. Thanks again.......... ALAN

 

[LubeDude]

Re: Need some advice guys. I got a good scare Saturday.

I also have an in-line filter installed between the pickup tube and water separator.

This may be the problem, I assume that it`s an automotive type filter. This may be way too restrictive and it`s unnecesary anyway. Try removing it and let us know.

 

[Theoutdoorsman]

Re: Need some advice guys. I got a good scare Saturday.

Thanks for the reply Admiral. I'll remove the automotive filter in a few minutes and let you know on the priming issue. However, as stated above, I do not have a filter installed on the pump. Is there an alternative to the automotive filter? Or will the seperator pretty much catch whatever debris that invades the fuel supply? Thanks again.......... ALAN

 

[Theoutdoorsman]

Re: Need some advice guys. I got a good scare Saturday.

I'm still experiencing the same problems. It's idling a little rough as well as showing signs of a decrease in power. Not to mention sluggish. I suppose I'll have to remove the carbs tomorrow and inspect for blockage. No big deal though, it'll just take a little time. And better safe than sorry I suppose. I'll get back with you fellows on what, if anything, I find. Thanks again............ALAN

 

[Theoutdoorsman]

Re: Need some advice guys. I got a good scare Saturday.

Well....... I removed, cleaned, and replaced the carbs. Same old, same old. It sounds like there is a mild rattle internally and it acts like it wants to go, but can't. I'll try to explain this as best I can........ Imagine going through some big waves. When you hit a wave the boat, via plowing, seems to be held back. When you exit the wave, you can feel it "take off". This is what I'm experiencing, only on water with no wave action???? WOT RPM's have dropped from 5900 down to 5200. (I only see a variation of about 200 rpms while under way.) Would a fuel delivery problem cause the rattle I'm hearing? Compression is fine. I'm at a total loss here. If a rod bearing was going out, would I be experiencing these same symptoms? Thanks for any and all assistance................. ALAN

 

[Silvertip]

Re: Need some advice guys. I got a good scare Saturday.

Have you actually run the motor on a different tank?

 

[Theoutdoorsman]

Re: Need some advice guys. I got a good scare Saturday.

Have you actually run the motor on a different tank?

Not yet Silvertip. But I do have a test tank to do this. Though there is a slight rattle, do you still believe it's a fuel delivery problem? If I did, in fact, have a rod bearing going bad, would I be experiencing the same ill effects? I'm looking for a big "NO" here to settle my nerves....... I'll run it on the test tank and get back to you. Thanks.......... ALAN

 

[iwombat]

Re: Need some advice guys. I got a good scare Saturday.

I'm wondering if maybe that much vacuum in your fuel pump tore up the membrane inside and now you've got a fuel leak in through the pulse orifice. It would explain why it's hard to prime too. Do you ever get a nice firm bulb when you prime or does it go soft pretty quickly?