1983 15hp Evinrude runs 5 mins, then stalls

[Motorbtr]

My motor starts fairly easy, runs for several minutes, and then dies. I just bought it from a guy who stored it for 10yrs and had it tuned up by a mechanic before placing in storage.
I carefully rebuilt the fuel pump (old one looked ok upon dissasembly) and carberator. The fuel pump passed the blow through the intake but not the outflow test. The float bowl in the carb was bone dry (after running) before I rebuilt it, and had a light coating of red rust on the bottom. I took the plastics off and soaked it overnight in laquer thinner. When rebuilding I was careful to adjust the new float correctly. I screwed the low-end needle valve in all the way, then backed it out 1 1/2 turns. There is no high-end needle valve or orifice on the float bowl. I lubed it up with Marvel Mystery Oil during reassembly.
With a little carb cleaner sprayed in the intake, the engine started up after a couple of pulls. It ran a little longer than before, but still stalls out after 3-8 minutes. If I squeeze the fuel bulb just before it stalls, sometimes it will stay running. I switched gas tanks, lines/plugs, new gas/oil, loosened gas caps, etc, but the engine still stalls. I haven't pulled the rebuilt carb to check if fuel is getting in the float bowl yet.
I pulled the plugs and they have wet oil and a little crud on them (fowled?). I put new plugs in and got the same thing after running a few minutes. I'm running on a stand with a garden hose hooked up to "earmuffs" over the intakes.
Does anyone know what is wrong? I've cleaned and rebuilt everything on the fuel system I can think of. Are the fowled plugs causing my engine to stall? I don't think I'm running it too rich. The needle adjustment is for low speed, but the enginge stalls at all speeds, eventually. Thanks!!

 

[Homedad]

Re: 1983 15hp Evinrude runs 5 mins, then stalls

Sounds like something was messed up in the reassembly of your fuel pump. I had the same issue on my trolling motor and gave up on it and just purchased another from ebay. Good luck those things are a pain once they are taken apart.

 

[shipwreck]

Re: 1983 15hp Evinrude runs 5 mins, then stalls

When stop running squirts some fuel mix if is two stroke into carb.
If start up then it is fuel system problem.

How hot is engine getting, dose have water stream out of pee hole ( that show the impeller is working).
If motor dose not restart right wait but wait a 5 - 10 mines. It could be overheating ( should run to far past idle on muffes) or water passage could be blocked - or bad t-stat.

Also one of the coils could be the ign. system could be failing under load.

If think the work you have done on it is good , you can check these areas too.

 

[Motorbtr]

Re: 1983 15hp Evinrude runs 5 mins, then stalls

I was careful to assemble the fuel pump correctly, though it would be easy to get the little squares 90-180 degrees off. The problem did not change between having the old pump on the motor and the rebuilt one. If anything, it runs a little bit longer.
I don't think it is over heating. It's not running very long, maybe 10min at the most. Water is streaming out of the pee hole.
The throttle response seems to be a little bit sluggish, though I've never seen the engine run properly to have a baseline to judge it by.
Any idea why the plugs would have oil on them?

 

[shipwreck]

Re: 1983 15hp Evinrude runs 5 mins, then stalls

how long dose take to restart after stops . Start motor or pull type?
Again if stops and u squirt fuel into carb and start up then carb problem.

Is a two stroke? or four stroke

 

[Motorbtr]

Re: 1983 15hp Evinrude runs 5 mins, then stalls

It's a 2 stroke pull-start. After stalling, it will normally start right back up in 1-4 pulls.
I cleaned out everything in the carb I could think of. The only thing I didn't do was replace some of the little freeze plugs(?)and clean behind them because I didn't know how to get the old ones out. I'd think the overnight soak would have gotten all the cavities clean.
I'll check the float bowl tomorrow and see if there's fuel in it after running.

 

[jonesg]

Re: 1983 15hp Evinrude runs 5 mins, then stalls

drive an ice pick into freeze plug then just lift it out, tap new ones into place.
a nail might work too.
do you have a carb rebuild kit?
It needs it.

 

[Vic.S]

Re: 1983 15hp Evinrude runs 5 mins, then stalls

If it starts easily and runs Ok for several minutes it seems to me very unlikely that its is a carb problem. Sounds more like fuel flow/supply or pump problem. Its running on the initial fill of the bowl and petering out when that is used up.

Tank vent, air ingress to fuel line, partly blocked fuel line or filter and fuel pump are all areas I would look at before stripping down the carb again!. Easy low cost things first. Difficult or expensive things last.

Have you tried gently pumping the bulb. If that keeps it going then it just about rules out any carb problems.

 

[Rick.]

Re: 1983 15hp Evinrude runs 5 mins, then stalls

Sounds like your running out of fuel to me. The plugs have oil on them because of the oil/gas mix a 2 stroke runs on. It is normal. Try elevating your gas tank a couple of feet higher than the carb. This will allow gas to get to the carb. by gravity rather than depending on the fuel pump fo lift it. When testing my motors, I always put the tank close to the same height it would be in the boat ( in relation to the motor), never on the floor. Let us know how it is going. Rick.
If you get it working put a new impeller in it before heading out. Yours is far to old to depend on and the ramifications could spell disaster if yours fails)

 

[Motorbtr]

Re: 1983 15hp Evinrude runs 5 mins, then stalls

I swapped an old weathered fuel pump off my friend's nearly identical (a few years older) 15hp Evinrude today. The motor ran great, so it was my fuel pump. Not sure what I did wrong rebuilding it, but I'm going to rebuild it again tonight and check for wrinkled diaphrams, etc. I compared pumps and all the squares were lined up correctly and matched. Any common mistakes in rebuilding these pumps? Thanks for all your guys help with this!

 

[Rick.]

Re: 1983 15hp Evinrude runs 5 mins, then stalls

Glad you were able to borrow another pump. That is a great way to trouble shoot a problem. Not sure if you have this link on rebuilding the pump. I think his work is a must read for all us 9.9 and 15 owners. Has been very helpful to get to know my motors better. Rick.

http://www.sschapterpsa.com/ramblings/OMC/OMC info.htm

 

[P 0 P E Y E]

Re: 1983 15hp Evinrude runs 5 mins, then stalls

Congrats on the fix.

Some good tips in all the posts above.

 

[Motorbtr]

Re: 1983 15hp Evinrude runs 5 mins, then stalls

Got it fixed! I had installed one of the squares on the fuel pump 90 degrees off. In step 18 (http://www.sschapterpsa.com/ramblings/Rebuilding_fuelpump.htm) my outflow valve is on the right, instead of the left as pictured. I lined up the tab on the metal plate (with the "U" stamp) with the wide black tab, instead of the narrow one (Tab "B"). I turned it 90 degrees, bolted it back on, fired the engine up, and it ran great.

The first time I assembled the pump (incorrectly) it passed the blow-through test with no resistance. When correctly assembled, there was some resistance from a diaphram when I blew through. It also made a sound like a reed or kazoo.

Now on to the lower end for a gear oil change and impeller change. Water is also leaking on the right side where the lower unit attaches to the upper unit (replace lower grommet on water pump outlet?). I'll have to look a little closer to see where exactly it it coming from.

Thanks again for your guys help so far!

 

[Rick.]

Re: 1983 15hp Evinrude runs 5 mins, then stalls

Good for you. The water (I'm not sure what is right and left in your mind) could be a leak from the tell tale hose on the starboard side Take a careful look. Rick.