This is driving me nuts

arkansasbasser · 09-23-2009, 06:15 PM

I have a 1983 35 hp Evinrude outboard. I can start it and it runs well for 5-20 minutes then the engine lugs down. If you keep the throttle wide open you will go a little faster than idle. If you let off it dies and then it's hard getting it started again. I have changed all the hoses, cleaned the intake jet in the carb bowl. I've changed gas tanks. When it lugs down, if you take it down to idle for a while, it will take off again after 5-10 minutes of idling then run for 5 minutes and lugs down again. Maybe electrical?

baitsauce · 09-23-2009, 08:31 PM

E-10 fuel is the cause of your problems. The carb(s) are probably in need of a rebuild. More accurately the emulsifier tube(s) have tiny (and I mean tiny) cracks.

There is a corrosion issue caused by dissimilar metals. The water the E-10 picks up causes the corrosion.

Isn't E-10 great!?!?!?

My

//

arkansasbasser · 09-24-2009, 08:08 AM

Thanks. Guess I'll do a rebuild. BTW, what does an emulsifier tube do?

baitsauce · 09-24-2009, 03:46 PM

In a nutshell, the emulsifier tube is what changes the gasoline into a mist so it will burn. That is it sucks gasoline out of the bowl and provides it with a path to the jet(s). The problem is if they are cracked then they will suck air instead of gasoline.

The rebuild kit should come with a new one. If it doesn't and this is indeed your problem then a rebuild will do you no good.

I'm kinda interested in your case arkansasbasser. So do me a favor and keep me in the loop on this. Shoot me a PM or something to let me know how it turned out.

arkansasbasser · 09-25-2009, 05:20 AM

Will do. Yesterday I removed the carb and ran a small diameter wire up thru the tube. I encountered some resistance about halfway. I pushed through and the tube seem to be clean at that point. I re-assembled and installed it back.

I have the lower unit in a trash can of water. When I cranked the motor it started up and since I've owned that motor it hasn't idled as smoothly as it did now. When I put it in gear it would die, which it had not been doing. Then I noticed there wasn't any water coming out of from the water pump so I shut it down. Today I will see about installing a new water pump and go from there.

12pulls · 09-26-2009, 09:23 AM

Quote:

Originally Posted by arkansasbasser

Will do. Yesterday I removed the carb and ran a small diameter wire up thru the tube. I encountered some resistance about halfway. I pushed through and the tube seem to be clean at that point. I re-assembled and installed it back.

I have the lower unit in a trash can of water. When I cranked the motor it started up and since I've owned that motor it hasn't idled as smoothly as it did now. When I put it in gear it would die, which it had not been doing. Then I noticed there wasn't any water coming out of from the water pump so I shut it down. Today I will see about installing a new water pump and go from there.

First check to see if you have an obstruction in the pee tube. Wasps love them this time of year, I had one already this fall filling mine with mud. Several years ago they packed my thermostat with muck.

Ironhead · 09-26-2009, 09:41 AM

One thing to think of is when the outboard has not not been run for awhile and the fuel is sitting in the fuel bowl. The fuel will evaporate and just leave the oil mix and the remaining fuel additives. These tend to form a gooey mess that will plug up small orifices and such . Did you ever notice how much a 2 stroke smokes when it has`nt been run for a while . It`s the extra oil left from evaporation of the gas. When you pump up the fuel bulb it reintroduces fresh fuel which mixes with the oil left behind. Also alcohol attacks alot of rubber products causing them to swell and break down. Also check the fuel pump . It has a diaphram in it .

arkansasbasser · 10-04-2009, 09:49 AM

Quote:

Originally Posted by baitsauce

In a nutshell, the emulsifier tube is what changes the gasoline into a mist so it will burn. That is it sucks gasoline out of the bowl and provides it with a path to the jet(s). The problem is if they are cracked then they will suck air instead of gasoline.

The rebuild kit should come with a new one. If it doesn't and this is indeed your problem then a rebuild will do you no good.

I'm kinda interested in your case arkansasbasser. So do me a favor and keep me in the loop on this. Shoot me a PM or something to let me know how it turned out.

So far I have replace the carb, fuel pump, water pump, spark plugs and wires, and fuel hoses. Fuel and water pumps are working correctly.

I still have the same thing going on. It runs fine with no load but as soon as you load it up it lugs out. The only thing left, in my opinion, is electrical. Any other advice? BIll

veilside180sx · 10-04-2009, 10:36 AM

Spark blowing out under load?

baitsauce · 10-04-2009, 02:44 PM

Quote:

Originally Posted by arkansasbasser

So far I have replace the carb, fuel pump, water pump, spark plugs and wires, and fuel hoses. Fuel and water pumps are working correctly.

I still have the same thing going on. It runs fine with no load but as soon as you load it up it lugs out. The only thing left, in my opinion, is electrical. Any other advice? BIll

Damb, that sucks Bill.

Here's an old trick I've used with some success.

I'm assuming the motor is on the boat. If so take it to the boat launch after it gets dark. With the cover removed start it up. Let it get warm and try running it at different speeds. Then put it under a load and put it into gear. You may see some "leaking spark" along the spark plug wires and/or spark plug boots.

If you do then the problem will be obvious.

//

baitsauce · 10-04-2009, 02:54 PM

Another check to make would be the coil and the ground for the coil.

You can check those with a multimeter. I won't go into it here, but if your'e interested then let me know and I'll be happy to post the procedure.

Bloom · 10-04-2009, 04:17 PM

[QUOTE=baitsauce;2756914]Another check to make would be the coil and the ground for the coil.

Yes on that. Even a weak coil will produce a good looking spark not under a load, but add compression and the party's over.Don't test it by holding the plug wire while you are cranking, not good!

Highmark · 10-05-2009, 04:37 AM

I had this happen to me On my 90 . what I found after after doing all you have done, and some. was I had a fuel line kinked behind a wall in the back of the boat. that was restricting the gas flow at any thing above and idle, After fixing the kink, it ran like new.

arkansasbasser · 10-05-2009, 06:13 AM

Quote:

Originally Posted by Highmark

I had this happen to me On my 90 . what I found after after doing all you have done, and some. was I had a fuel line kinked behind a wall in the back of the boat. that was restricting the gas flow at any thing above and idle, After fixing the kink, it ran like new.

I thought something along the same lines and switched gas tanks with it's own line and nothing changed.

fishkisser · 10-05-2009, 08:25 AM

After some thought , I wondered if you had checked compression in your cylinders ...
They should be within less than ten pounds of each other , if one is low by 10 pounds
or more it could cause the running problems you are experiencing also ...

Good luck ... Barney

arkansasbasser · 10-05-2009, 09:29 AM

Quote:

Originally Posted by fishkisser

After some thought , I wondered if you had checked compression in your cylinders ...
They should be within less than ten pounds of each other , if one is low by 10 pounds
or more it could cause the running problems you are experiencing also ...

Good luck ... Barney

Thanks for the reply. After giving that some thought it seems to me that it wouldn't be intermitent if that was the case?

fishkisser · 10-05-2009, 06:17 PM

It would if the loss of compression is attributed to a leaking head gasket
and not bad rings on the piston ...
As the motor under load heats up and expands the compression is lost
as it cools down idling with water circulating it regains some compression ...
I'm only tryng to help as I read in one of your previous posts that you
discovered it was not shooting water out of the telltale (peeing) ...
This could easily caused a blown head gasket if left undetected for a
short period of time ...
Once again , luck to you on your motor fix ... Barney

arkansasbasser · 10-07-2009, 08:31 AM

Quote:

Originally Posted by fishkisser

It would if the loss of compression is attributed to a leaking head gasket
and not bad rings on the piston ...
As the motor under load heats up and expands the compression is lost
as it cools down idling with water circulating it regains some compression ...
I'm only tryng to help as I read in one of your previous posts that you
discovered it was not shooting water out of the telltale (peeing) ...
This could easily caused a blown head gasket if left undetected for a
short period of time ...
Once again , luck to you on your motor fix ... Barney

Thanks. I'll check that out.

Deanrt · 10-19-2009, 07:43 PM

I have a '76 35 hp Evinrude and a problem kinda like yours. In the pic I added, looking at the motor from behind on the left side below the flywheel you may see this linkage. The flat head screw adjusts the brass piece. Mine some how moved and it did some of the things you describe. I was able to get it set right after many tries. Might be something to look at. Good luck.

arkansasbasser · 11-27-2009, 08:19 PM

Turned out it was a cracked coil on the top cylinder. When it warmed up the crack would open up and the voltage would leak out. Thanks to all who responded to this thread.