1979 Evinrude 140 rpm woes....still.

[Theoutdoorsman]

I'm having a problem with my recently rebuilt 1979 Evinrude 140. My problems began when I noticed this......

This photo is of the wires, running from the stator, to the starboard side power pack. Notice it has been rubbing the flywheel and the wire was exposed. I peeled back the cover, for illustration purposes, so you can see it was obviously worn. I repaired the frayed insulation via rapping it with some electrical tape and securing it snuggly against the top of the block and out of the way of the flywheel. The reason I found this was because my motor would not turn the usual rpm's and had a knocking sound. I thought I may have had a rod bearing going bad. Once the wire was repaired, I noticed a MAJOR difference in performance. However, I am still puzzled at WHY the outboard is still not performing up to it's full potential. I used to be able to turn my current prop at 5900 rpm's all day long. Now, it will run flawlessly at 5200 rpm's all day long, but, anything beyond that and it is as if someone reaches over and pulls the safety lanyard. Compression is fine. Carbs have been rebuilt numerous times. I've linked and sync'd as per the manual several times, and still the problem exists. Anyone have any other ideas on this? Here's a link to the original thread. It may shed some more light on my findings....... http://forums.iboats.com/showthread.php?t=190100&highlight=Theoutdoorsman ....... Any further advice or idea's on this would be much appreciated............. ALAN



EDIT: Just for the record, the motor run's and sounds great!!! I ONLY have problems when accelerating beyond 5200 rpm's and that as long as I opperate within this rpm range, it will run absolutely flawlessly the entire day long. I'm certainly stumped. I'm thinking a new power pack may be in my near future. I just wanted to pick the brains of some other folks in-the-know prior to making a purchase and wasting money. Thanks again.

 

[Silvertip]

Re: 1979 Evinrude 140 rpm woes....still.

If it runs fine up to 5200 it probably is not a power pack issue. It is more than likely a fuel issue. I would suspect a weak fuel pump or a fuel restriction. If the fuel tank has an anti-siphon valve, check it or remove it for testing. It screws into the outlet of the tank and the fuel line connects to it. The check ball may be sticking. The filter screen on the fuel tank pickup may be partially clogged. The fuel line may be kinked or pinched. When you get to 5200 have someone squeeze the primer bulb quickly to see if the engine picks up. If it does, you confirmed the fuel delivery problem. If not, you need to check if the carb butterflies are perfectly horizontal in the carb bores at wide open throttle. If not -- you have an incorrect link and sync or there is a throttle cable issue. Is wide open throttle timing set correctly after the rebuild? Those a just a dozen or so things that will prevent wide open throttle performance.

 

[flabum]

Re: 1979 Evinrude 140 rpm woes....still.

It could be a lot of things......how old are the fuel lines? A collapsed fuel line can have you running in circles.

 

[Theoutdoorsman]

Re: 1979 Evinrude 140 rpm woes....still.

If it runs fine up to 5200 it probably is not a power pack issue. It is more than likely a fuel issue. I would suspect a weak fuel pump or a fuel restriction. If the fuel tank has an anti-siphon valve, check it or remove it for testing. It screws into the outlet of the tank and the fuel line connects to it. The check ball may be sticking. The filter screen on the fuel tank pickup may be partially clogged. The fuel line may be kinked or pinched. When you get to 5200 have someone squeeze the primer bulb quickly to see if the engine picks up. If it does, you confirmed the fuel delivery problem. If not, you need to check if the carb butterflies are perfectly horizontal in the carb bores at wide open throttle. If not -- you have an incorrect link and sync or there is a throttle cable issue. Is wide open throttle timing set correctly after the rebuild? Those a just a dozen or so things that will prevent wide open throttle performance.

This was originally pondered earlier in my investigation, as per the link above. The antisiphon valve has been removed. All fuel lines are brand new. Tried squeezing the bulb to no avail. I have also been through the link and sync a dozen times. Even checked it with a timing light. All is good. The link and sync was performed as per Joe Reeve's suggestions through our earlier conversations. As stated above, the motor ran absolutely perfect until that wire was frayed. It's sure got me puzzled. I would suspect it's a carb issue, but after removing, cleaning, and reinstalling them several times, I don't think it is. I thought, at one time, that I had a float out of adjustment. Nope, all is good there too. I have photo's if you care to see them. They are spotless and every piece is brand new. I might add, when it falls on it's face at WOT, I can pull back on the controls, pump it a couple times, and it will recover. Whereas, I can increase throttle back to the 5200 rpm range, and cruise the rest of the day there.......flawlessly. This just doesn't make sense to me. I'm really stumped.

 

[emdsapmgr]

Re: 1979 Evinrude 140 rpm woes....still.

When you "secured the wires," is there any chance that they are inhibiting the other power pack wires that move with the timer base? The link arm must be free to pull the timer base to the full advance timing stop. If this wire harness is secured and prevents the timer base from moving to full timing, you could be losing your full advance feature. Also, I'd use a peak-reading voltmeter to check the output of the stator. Possible it was damaged when the wire frayed.

 

[Theoutdoorsman]

Re: 1979 Evinrude 140 rpm woes....still.

When you "secured the wires," is there any chance that they are inhibiting the other power pack wires that move with the timer base? The link arm must be free to pull the timer base to the full advance timing stop. If this wire harness is secured and prevents the timer base from moving to full timing, you could be losing your full advance feature.

I'm almost certain that it isn't inhibiting the movement. But I'll double check to be certain.

Also, I'd use a peak-reading voltmeter to check the output of the stator. Possible it was damaged when the wire frayed.

Can you tell me, specifically, how to check this. Although I have all the diagrams in hand, electical troubleshooting was never one of my strongpoints. Does the outboard need to be running to check this?

Thanks a bunch for the reply. I'd almost given up on the thread.

 

[emdsapmgr]

Re: 1979 Evinrude 140 rpm woes....still.

You will need an adapter for a typical hand held volt/ohm meter that will enable your meter to read peak volts. A regular meter will not read peak volts correctly. You test the stator by cranking it over and measuring output. Your OEM service manual lists two types of testing, ohms testing and the peak volt method. Once your meter is setup, you can also use these tests on the timer base.

 

[Theoutdoorsman]

Re: 1979 Evinrude 140 rpm woes....still.

You will need an adapter for a typical hand held volt/ohm meter that will enable your meter to read peak volts. A regular meter will not read peak volts correctly. You test the stator by cranking it over and measuring output. Your OEM service manual lists two types of testing, ohms testing and the peak volt method. Once your meter is setup, you can also use these tests on the timer base.

Where can I find this "adapter" your talking about. Can you post a link to one so that I can see exactly what it is that your talking about. I have several friends who are mechanics and I might be able to get my hands on one. Thanks agian......... ALAN

 

[HighTrim]

Re: 1979 Evinrude 140 rpm woes....still.

What he is referring to is a DVA adapter, or a DVA meter if you have one. The adapters are cheaper.

http://cgi.ebay.com/ebaymotors/STAT...020QQitemZ300206164907QQrdZ1QQsspagenameZWDVW

 

[Theoutdoorsman]

Re: 1979 Evinrude 140 rpm woes....still.

Thanks for the info guys!! The timer base if functioning properly, in that it is reaching the stop. If it were somehow damaged when that wire frayed, what other ill effects would/could I be experienceing, if any? I'll see if I can locate the adapter today. If not, I'll buy one to test with. Might come in handy for other projects later on anyhow.... .... Thanks again!!......... ALAN

 

[reeldutch]

Re: 1979 Evinrude 140 rpm woes....still.

when your outboard turns over 5200 flawlessly that means that your ignition system is working properly.

after max spark advance is reached only the trothle valves open up more without advancing spark so only fuel suply will give you more rpm's at this point.

find a testwheel en run the motor to wot and see what you get.
you might have other problems than engine problems.
may be prop damage?
may be extra load on the boat?


what do you mean with its like somebody pulls the safety lanyard.
are you going beyond 5200 and than it drops back suddenly?

 

[Theoutdoorsman]

Re: 1979 Evinrude 140 rpm woes....still.

What do you mean with its like somebody pulls the safety lanyard. Are you going beyond 5200 and than it drops back suddenly?

The outboard will run very briefly at WOT and then suddenly begin deceleration as if it were running out of fuel............ bluuuuuhhhhhh. Like that......... ..... Sorry, not being a smartalek, that's just the only way I know how to explain it..... LOL ...... At, or below, 5200 rpm's it will simply purr all day long without missing a beat. Makes no sense to me. As long as I don't take it above 52, she's fine. I have a great hole shot (on plane in 3/4 of the boats length!), excellent acceleration, and a nice top end. It very well may be a fuel related problem. But it sure is funny that this didn't begin until that wire frayed. At first, I thought I ran out of fuel and sucked some crap up in the carbs from the bottom of the fuel cell, because I know for sure it was extremely low on fuel. When I removed the carbs for inspection and cleaning, they were spotless (cleaned them again anyway). I reinstalled the carbs and completed my link and sync according to Joe Reeves personal instructions. Same thing happened next trip out. It's got to be something so simple it isn't funny. I've considered re-installing an electric fuel pump just to rule out a bad or failing "on-board" fuel pump. I've even considered bypassing my water seperator to see if this makes a difference in fuel delivery. Maybe these are worth a try, I don't know. What I do know, is that this is really bugging me to death. I just figured if I test the electrical system, at least I can possibly rule something out and make some kind of progress towards getting this thing right again. Thanks............. ALAN

EDIT: I might also add, if I do not pull back on the controls, it will completely shut down. However, If I pull back on the controls and throttle up again, it will recover and begin purring again. Makes no sense. Bare in mind also, before the problem started, the outboard was turning the prop at about 5900 rpm's at WOT without any problems whatsoever. Below is a photo of the newly secured stater wire at WOT. As you can tell, the timer base is definitely reaching it's stop. One thing I did notice today, however, was that one or both carbs are now pouring fuel if I continue to apply pressure to the bulb. So I guess I need to readjust floats and/or clean them again....... :-( ........ A never ending battle isn't it.......LOL

 

[emdsapmgr]

Re: 1979 Evinrude 140 rpm woes....still.

You may be running out of fuel. Over 5200 you consume more fuel than the system can deliver, and it will sputter or quit. The engine will run full speed, till the fuel bowls run dry. Pulling back the trottle lets them refill. Try priming the hose bulb when you are at 5200, then put the throttle down. If constant squeezing the bulb keeps it from faltering, you may have a bad fuel pump, a kink in the line, or even a loose fuel hose.

 

[wavrider]

Re: 1979 Evinrude 140 rpm woes....still.

I chased the same gremlin on a 115hp and after going through the whole ignition system, carbs 3 times, tried electric fuel pumps, still stalled at wot, run beautiful at 4000 rpm.
I replumbed the whole fuel system with bigger fuel line, and installed new omc fuel pump, runs great at wot.
Sounds like weak fuel pump.

 

[ezeke]

Re: 1979 Evinrude 140 rpm woes....still.

I never felt the single fuel pump was adequate for the top end of the 140. The two lift pump system that they used on the 150 could deliver a lot better.

Most of the 150s were set up with 3/8 lines and fittings as well. When that extra 140HP top end power kicks in that the 90hp and 115Hp engines don't have, that is a serious engine.

 

[Theoutdoorsman]

Re: 1979 Evinrude 140 rpm woes....still.

I never felt the single fuel pump was adequate for the top end of the 140. The two lift pump system that they used on the 150 could deliver a lot better.

Most of the 150s were set up with 3/8 lines and fittings as well. When that extra 140HP top end power kicks in that the 90hp and 115Hp engines don't have, that is a serious engine.

Maybe I need to revamp the entire fuel delivery system with the 3/8" lines and so forth and complete the setup with an electric fuel pump again. I'm pretty certain, now, that I'm not getting an adequate supply of fuel. But why would it suddenly do this after fraying the wire? All was well before. I do have a rebuild kit on hand for the fuel pump. Sooooo......I think I'll rebuild the carbs, do one more link and sync, rebuild the fuel pump, take a few pictures or video to help show you gentlemen exactly what's going on, and ponder the revamp of the fuel delivery with 3/8" lines should the problem persist. Gota start somewhere I suppose. Thanks for the suggestions guy's!!!! Much appreciated!!!..........ALAN

 

[Theoutdoorsman]

Re: 1979 Evinrude 140 rpm woes....still.

If someone could point me to the rebuild kits for these carbs I sure would appreciate it. I've looked here at iBoats but all I can find is the kits without the float assembly. If I'm going back in there I'd just soon go ahead and replace everything, including my floats, even though they are just a little over a year old. Anyone know where I can find the complete kit w/float assemblies? Thanks a bunch in advance........... ALAN

 

[ezeke]

Re: 1979 Evinrude 140 rpm woes....still.

Only the OEM Kits have the floats #383,437. By the time you buy the floats separately, you have not saved anything. OEM kit is 0439076.

 

[wavrider]

Re: 1979 Evinrude 140 rpm woes....still.

If your floats are good you do not need to buy new ones.
Save the money for all the gas that ole engine is going to drink.

I chased a fuel gremlin on my 115, i just said the heck with it, rebuilt carbs, 3/8 line all the way through out including fuel line from tank, new primer bulb and new fuel pump.

Have not had a problem since. Let us know how it turns out.

 

[TD_Maker]

Re: 1979 Evinrude 140 rpm woes....still.

Outdoorsman,
I have owned several of these V-4 motors. This may be a long shot, but I had a problem like this once. I once replaced my fuel line with a inexpensive unit from Wally World. The motor did the same thing yours is doing. It drove me crazy. Change out the fuel line and see what happens.