1967 evinrude big twin 40hp

[jensengt4]

hi will a fuel pump work upside down? i got a new one from ebay 25hp to 55hp, the seller told me it will work for my engine but its slightly bigger & hits the throttle arm at the top so i flipped it over & went out for test run but no change compared to the old one, when i go past 3/4 throttle the engine cuts out after 20seconds or so some times i can catch it if i back it of quick. lower down the rev rangd its ok.

so far its got
new plugs
new coils
new points
new fuel pump
new starter motor

& i just ordered a manual

 

[1946Zephyr]

Re: 1967 evinrude big twin 40hp

Hmmmm, never tried running one upside down before. I know the older ones, with the glass bowl on them cant be run upside down, but I don't know about the later type.

 

[F_R]

Re: 1967 evinrude big twin 40hp

Well yes and no. In theory they will work upside down. In reality, maybe not. The reason is the outlet valve is supposed to be at the top so any air bubbles (which rise to the top) are expelled. If mounted upside down, it won't expell the air and may actually fill with a quite large gob of air. The result is as the diaphragm moves back and forth it simply compresses and relaxes the air bubble, instead of moving fuel which doesn't compress.

 

[kfa4303]

Re: 1967 evinrude big twin 40hp

HI jensengt4. Welcome to iboats. I actually asked the same question the other day and was told that it shouldn't matter if the fuel pump is mounted with the pointed end up or down, assuming the lines are plumbed properly, of course which makes sense to me. Does the engine start and idle well? If so, I'm tempted to think that you may have an issue with the float needle. You may also want/need to adjust the hi speed needle a bit, if you have one. I had a '66 33 hp that had both the Lo and Hi speed adjustable needles. A third possibility is that you need to perform a "Link and Synch" which optimizes (optomises across the pond, I believe) the action of the carburetor and timing of the engine. Herewith hope they serve.

http://forums.iboats.com/showthread.php?t=167352

http://www.duckworksmagazine.com/04/s/columns/max/24/index.cfm

http://forums.iboats.com/showthread.php?t=511739&highlight=link+synch (look at post #7 and below)

 

[jensengt4]

Re: 1967 evinrude big twin 40hp

a pic of the new pump. its runing just as it did with the old one so is it the pump?

 

[jensengt4]

Re: 1967 evinrude big twin 40hp

you lot are fast was just geting a pic

 

[lindy46]

Re: 1967 evinrude big twin 40hp

Apparently not the pump. When you say it "cuts out", is it like it totally quits running (like you turned the key off) or does it sputter and miss and lose rpms?

 

[kfa4303]

Re: 1967 evinrude big twin 40hp

I would defer to F_R on the inverted pump (and all other boat) issue, but it doesn't seem to be the culprit in this particular case given the symptoms. However, there is one simple thing you can do to help monitor the performance of the pump, such as it is. If you install one of the clear, inline fuel filters in the pic below, you will not only help to keep debris out of the carb, but it also provides visual verification of fuel delivery. They can be found at most auto parts stores for 1 or 2 quid. They're very easy to install and well worth the effort. I've put them on all of my vintage outboards in the line leading from the fuel pump to the carb. If it is dying entirely at 3/4 throttle, then you may have a spark issue. Perhaps one of the spark plug wires is loose. You have to be sure to twist them onto the coil posts rather than simply poking them on there. In any event, be systematic. Once fuel is confirmed we can move on to spark. Stick with it. These old "Big Twins" are well worth the effort. Cheers!

 

[jensengt4]

Re: 1967 evinrude big twin 40hp

Apparently not the pump. When you say it "cuts out", is it like it totally quits running (like you turned the key off) or does it sputter and miss and lose rpms?

it just cuts out

 

[jensengt4]

Re: 1967 evinrude big twin 40hp

I would defer to F_R on the inverted pump issue. However, there is one simple thing you can do to help monitor the performance of the pump, such as it is. If you install one of the clear, inline fuel filters in the pic below, you will not only help to keep debris out of the carb, but it also provides visual verification of fuel delivery. They can be found at most auto parts stores for 1 or 2 quid. They're very easy to install and well worth the effort. I've put them on all of my vintage outboards in the line leading from the fuel pump to the carb.


View attachment 131078

that's a good idea

 

[lindy46]

Re: 1967 evinrude big twin 40hp

If it dies, like you shut the key off, you have an electrical issue.

 

[jensengt4]

Re: 1967 evinrude big twin 40hp

If it dies, like you shut the key off, you have an electrical issue.[/QUOT

will it be the cut out switch stopping it.

 

[kfa4303]

Re: 1967 evinrude big twin 40hp

It could be a short in the kill switch, but if you didn't fiddle with it specifically during the ignition rebuild, it's probably ok. I'd be more inclined to think it's the spark plug wires and/or a worn wire somewhere beneath the flywheel. If you didn't get new spark plug wires, I would highly recommend it. They make a world of difference and knowing that they are fresh and properly installed will eliminate a variable and give you peace of mind. If you do decide to replace them, be sure you get 7mm COPPER core wires. Modern automotive wires will not work. Small engine shops often sell it by the foot. On one end you crimp and/or solder on a 90 degree connector and boot, while the other end is twisted on to the post of the coil until it seats fully. Care should also be taken that the post is penetrating the copper core and not just the insulation. I know it's a bit of a pain removing the flywheel on these big old girls, but it may be worth it to remove it an inspect the ignition. Here are a few more links that deal specifically with the OMC universal magneto systems that was used on virtually all of their motors from the mid 50s-early 70's. Keep us posted. You'll get it.


http://www.duckworksmagazine.com/03/r/columns/max/07/index.htm

http://www.outboard-boat-motor-repa...on 3 HP 1952-1967 Ignition System Tune-up.htm

 

[lindy46]

Re: 1967 evinrude big twin 40hp

Could be a number of things - like kill wires shorting out. If they have any bare spots in the insulation near where they enter the magneto, the turning of the magneto when you advance the throttle could cause one or both to short out and lose spark to the cylinder(s). Also, the plug wires may not be seated fully into the coils as KFA mentioned. Did you secure the wire stops on the underside of the armature plate just before the wires enter the coil? Again, the turning of the magneto when you advance the throttle could cause pulling on the wires if they are not securely mounted in the coils.

 

[F_R]

Re: 1967 evinrude big twin 40hp

Call me old fashioned, but if I suspect a fuel pump problem, I test it. A fuel pump pressure gauge does the deed. OK, so you say you don't have one? Then pump the primer squeez bulb. If it keeps running, the pump is not doing its job. But other things can mimic a bad pump. An air leak anywhere between the fuel pump and the level of gasoline in the tank will do it. Don't overlook those little pins that get pushed in when you attach the connector to the tank. One of them has a tiny brass washer around it, with a tiny o-ring behind it. If that leaks, the motor will starve for fuel.

 

[jensengt4]

Re: 1967 evinrude big twin 40hp

Could be a number of things - like kill wires shorting out. If they have any bare spots in the insulation near where they enter the magneto, the turning of the magneto when you advance the throttle could cause one or both to short out and lose spark to the cylinder(s). Also, the plug wires may not be seated fully into the coils as KFA mentioned. Did you secure the wire stops on the underside of the armature plate just before the wires enter the coil? Again, the turning of the magneto when you advance the throttle could cause pulling on the wires if they are not securely mounted in the coils.

all the small wires look ok. i found a small split in one of the plug wires under a clamp its not deep but i will get some new ones. the plug caps i have are a spring with a sharp point that goes through the insulation are these ok ?

 

[jensengt4]

Re: 1967 evinrude big twin 40hp

Call me old fashioned, but if I suspect a fuel pump problem, I test it. A fuel pump pressure gauge does the deed. OK, so you say you don't have one? Then pump the primer squeez bulb. If it keeps running, the pump is not doing its job. But other things can mimic a bad pump. An air leak anywhere between the fuel pump and the level of gasoline in the tank will do it. Don't overlook those little pins that get pushed in when you attach the connector to the tank. One of them has a tiny brass washer around it, with a tiny o-ring behind it. If that leaks, the motor will starve for fuel.

the old pump was knacered by previous owner. the tank is new 22l with squeez bulb & connector

 

[kfa4303]

Re: 1967 evinrude big twin 40hp

Hello again Jensen. It doesn't look like the clamp has damaged the wire per se, but it does look rather old and worn out. I've never personally used the spring loaded boots, but that's what my motor had on it when I got, so they should work. Again, just be sure that the barb penetrates and makes contact with the copper core in the wire to ensure proper conduction. Here's a link to guy rebuilding his entire Evinrude from the ground up. Some of the early vids don't have sound for some reason, but the others do. You can watch the episodes regarding the ignition rebuild for guidance. You'll see that he goes to the extra effort of soldering the connectors to the spark plug wire. I didn't do that to mine, but otherwise followed the steps in the vid and now my motor starts on the first pull. Hope it helps.

I think you'll like his "New England" accent

http://www.youtube.com/watch?v=QW5wEnUeEew&list=UUqtXoVOxjtEKjjTKj0cFydg&index=22&feature=plcp