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1989 28 hp Evinrude sputtering/idle problem

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bergz22

Member
This was my grandpa's boat, he gave it to me when he passed. It is in really great shape and was hardly ever used, just sat in the garage. The engine sputters at idle and off idle, it sometimes puffs back out the carb. It runs really rough. It also idles real slow. I have checked the reeds, rebuilt the carburetor, new spark plugs, wires and ignition coils, water pump and lower unit seals, new fuel tank and fuel line, rebuilt fuel pump. Both cylinders are getting spark. Compression on both cylinders is 125 psi. I have the idle screw on the carb set at 1 1/4 turns out from all the way closed. I also have the little white screw you see at the end of the video turned all the way in. I have not driven the boat on the water yet. Sorry if the video is sideways, I didn't flip my phone while filming. It makes the one noise/sputter around 2:20.

I have also taken off the throttle cable, adjusted the white plastic screw all the way in and then adjusted the throttle cable out to match. Still having the same issue.

 
The white screw is simply to set the idle RPM "after" the slow speed needle valve is adjusted properly.

You may want to double check the high speed jet that's located horizontally in the bottom center of the float chamber... way in back of that drain screw. Best to carefully clean it with a piece of single strand wire as solvent just doesn't do that job properly.

On a flushette, the idle rpm depends on the shaft length, as follows:

20" shaft = 1000 rpm.
25" shaft = 1200 rpm.

In the water, the idle, due to back pressure, rpm will drop to normal.

(Carburetor Adjustment - Single S/S Adjustable Needle Valve)
(J. Reeves)

Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.

Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.

Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.

Thousands of parts in my remaining stock. Not able to list them all. Let me know what you need and I'll look it up for you. Visit my eBay auction at:

http://shop.ebay.com/Joe_OMC32/m.html?_dmd=1&_ipg=50&_sop=12&_rdc=1
 
When I rebuilt the carb I did pull out the high speed jet and was able to see through it. Is that ok? I will try doing this slow speed jet adjustment as soon as I can. How can I tell RPM if the boat doesn't have a tach? I was planning on adding one as soon as I can afford it.
 
bergz22 said:
When I rebuilt the carb I did pull out the high speed jet and was able to see through it. Is that ok? I will try doing this slow speed jet adjustment as soon as I can. How can I tell RPM if the boat doesn't have a tach? I was planning on adding one as soon as I can afford it.
Click to expand...

If the high speed jet was absolutely clean, that's fine.

No tachometer... If you can get the carburetor adjusted as it should be, just set the idle where you want it when the rig's in the water.
 
Sounds like it is only running on one cylinder to me. How are you checking for spark? It must jump a gap of at least 7/16 open air gap with a spark gap tester. When you say good spark it means nothing to us it must jump a 7/16 gap with a brite blue snap on both plug wires.
 
kimcrwbr1 said:
Sounds like it is only running on one cylinder to me. How are you checking for spark? It must jump a gap of at least 7/16 open air gap with a spark gap tester. When you say good spark it means nothing to us it must jump a 7/16 gap with a brite blue snap on both plug wires.
Click to expand...

I was using an inline spark tester with the flashing bulb. I'll have to pick up one of the adjustable ones. I borrowed out mine and never got it back.
 
bergz22 said:
I was using an inline spark tester with the flashing bulb. I'll have to pick up one of the adjustable ones. I borrowed out mine and never got it back.
Click to expand...

It's been said that "Eskimos" would loan out their wives for body heat purposes... and they come back good as new. They don't loan anything else for the reason you state! :cool:
 
Sorry it took me so long to get back, been battling a case of shingles the last week. Anyways today I tried to start it so I could do a cyl drop test. Couldn't even get it running long enough to do the test. When I got it running I had the warm up lever (if that's what it's called), next to the throttle all the way open and it would barely run. I did notice today that when I squeeze the primer bulb gas comes out of the brass tube in the carburetor. There was a puddle of gas in the carb and intake. There is also a puddle in the carb when the engine is running, even after I wipe it out. Also there is an oil slick in the garbage can I'm running it in, and dripping out small weep holes on the lower. This is after hardly running it. I don't think it is lower unit oil, I stuck my finger up the exhaust and it is in there too.




 
Sorry for taking so long to reply. I've been battling shingles. Anyways, motor runs really bad now. Can't even get it running long enough to pull a plug wire. I did notice that when I was squeezing the primer bulb fuel came out of the brass tube in front of the butterfly. After wiping it out more fuel was there while I was trying to run it. I made a post with more info and pictures but it hasn't been put up yet.
 
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You stated..... "I did notice that when I was squeezing the primer bulb fuel came out of the brass tube in from of the butterfly."
********************
That would be caused by either the air vent of the float chamber being clogged...OR... a float set wrong.
 
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joereeves said:
You stated..... "I did notice that when I was squeezing the primer bulb fuel came out of the brass tube in from of the butterfly."
********************
That would be caused by either tha air vent of the float chamber being clogged...OR... a float set wrong.
Click to expand...

I pulled the carb back off today. I tried to post Friday night with pictures but the post never showed on here.

Anyways, I set the float parallel to the carb body. I'm pretty sure I did everything right when I rebuilt it. The pictures in the manual I have don't match my carb.
 
bergz22 said:
Will do. I'm going to look and see if I can find the vent hole and make sure it's clean.
Click to expand...

Yes, they're hard to pinpoint as you search visually the underside of the upper body. There's never anything about that vent in the service manuals either. The first one I encountered (many years ago) that resulted in a flooding carburetor liked to have drove me nuts! Since then, if a carburetor floods and the float and float needle valve is okay, that's what I go for. Usually a case of Ant or Bee storage!
 
I looked at the underside of the carb body today. There are two holes. The hole on the left I had a welch plug in, but doesn't show it in the parts diagram. The right side was open. I blew air through both holes. The hole on the left is connected to a hole by the brass tubes. The hole on the right goes up to little holes above the throttle body blade.


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By watching some you tube videos I found out that a plug goes in the left side. Got the carb put back together. I can blow through the fuel intake port with the car right side up. Upside down I can't. I'm going to put it back on the motor in the next day or two and see what happens.
 
Got the carb back on today. Squeezed the hell out of the primer bulb and no fuel coming out anywhere. I'm going to run it tomorrow and see what happens.
 
Motor is running a lot better with the car rebuilt. No more oil in the water or fuel leaking. The motor idles, but seems to idle low and dies when put in gear. Did a cylinder drop test, it seems like the top cylinder isn't firing as well as the bottom. It will run decent with top cylinder plug wire pulled. Pull the bottom wire and it dies out quickly. I did test the spark, it does jump a 7/16 gap, but it isn't a bright blue spark that snaps.
 
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Running Decent with Top Wire Pulled, Dies Quick when pulling bottom tells me the TOP isn't firing..

If you pull the bottom plug and it stays running then the TOP is Firing..
If you pull the bottom and the engine dies, then the TOP is NOT Firing.

If you pull the TOP plug and it stays running then the Bottom is Firing..
If you pull the TOP and the engine dies, then the Bottom is NOT Firing.

make sense?
 
bergz22 said:
Did a cylinder drop test, it seems like the top cylinder isn't firing as well as the bottom. It will run decent with top cylinder plug wire pulled. Pull the bottom blue wire and it dies out quickly. I did test the spark, it does jump a 7/16 gap, but it isn't a bright blue spark that snaps.
Click to expand...

With the compression being 125 on both cylinders and spark that will jump a 7/16" gap as you state, The engine should have a identical rpm drop when whatever spark plug wire is removed. That would indicate a difference in the fuel mixture being delivered.

Assuming that the carburetor cleaning was successful... AND... the tip of the needle valve taper is not flawed, the engine should be running perfectly.

Try adjusting the slow speed needle valve at idle again, as follows.

********************
(Carburetor Adjustment - Single S/S Adjustable Needle Valve)
(J. Reeves)

Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.

Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.

Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.
 
I will try this adjustment again. The spark did jump the 7/16 gap but it wasn't very bright or make a loud snap. Also, when I pull the top wire it will arc between the boot attached to the coil and the block.
 
Swap the coils around and see if the poor spark follows the coil. If it stays the same get the upgrade kit and put the module on the side of the motor. Both of the coils are probably still good.
 
joereeves said:
With the compression being 125 on both cylinders and spark that will jump a 7/16" gap as you state, The engine should have a identical rpm drop when whatever spark plug wire is removed. That would indicate a difference in the fuel mixture being delivered.

Assuming that the carburetor cleaning was successful... AND... the tip of the needle valve taper is not flawed, the engine should be running perfectly.

Try adjusting the slow speed needle valve at idle again, as follows.

********************
(Carburetor Adjustment - Single S/S Adjustable Needle Valve)
(J. Reeves)

Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.

Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.

Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.
Click to expand...

What do you mean by lower the rpm's again?
 
bergz22 said:
What do you mean by lower the rpm's again?
Click to expand...

You have the idle rpm where you want it when you start adjusting the needle valve.... now, as you adjust the needle valve in slightly (1/8 segments), the rpms will increase (or at least they should). When the rpms increase, you would want to lower it to the idle rpm.
 
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