115 johnson runs like crap take 2

[greghennings]

Hey guys, guess my original post about my 115 johnson not running got deleted. Last thing i saw was when i posted about not understanding why the engine wouldn't run on gas. I know replies were made but i never got to read them, anyone remember what they posted? What a pain in the @$$.

 

[boobie]

Nice site update, HUH ???? See if you can repost your original question.

 

[greghennings]

Basically i said i didn't understand why my outboard has compression minus one cylinder that is a little low, has spark being generated, has gas in the carbs but will not start. No cough, puff, or pop. Will start on starting fluid but only run as long as that lasts.

I still get error messages trying to do somethings...

 

[keefallan]

I know there a lot of places to go with this, but start with cleaning the carbs. If you only get it to run with ether, then it seems like you have fuel delivery issue. A motor needs 3 things....fuel, air and spark. You added the fuel with the ether and it ran with already existing spark and air!! I recommend getting the factory carb rebuild kits and got to town. It will probably fix the issue.

 

[greghennings]

Did the carb rebuild and fuel pump rebuild this winter. New problem to the mix, top carb isn't putting out any fuel. Bottom carb definitely working. Float bowls are full. Fuel pump is working, i can disconnect it from the carb and crank the motor and she pumps away. I'm going to take apart the top carb again and see if i missed something...

 

[Bosunsmate]

Maybe you put the float in upside down

 

[greghennings]

Did the carb rebuild and fuel pump rebuild this winter. New problem to the mix, top carb isn't putting out any fuel. Bottom carb definitely working. Float bowls are full. Fuel pump is working, i can disconnect it from the carb and crank the motor and she pumps away. I'm going to take apart the top carb again and see if i missed something...

 

[greghennings]

Maybe you put the float in upside down

Boy, i don't want to take those carbs apart again, twice now today, but dang it that would be something dumb i would do, put that float in backwards.

But, guess i'm gaining. Couldn't find any help getting a spark tester that was more than a light so i found a picture of a home made tester using a block of wood and two screws. Crude, but sure works. All 4 will jump a 7/16 gap, poor starter's gonna go out next with all this cranking

.

top carb out and recleaned sprayed every orifice and made sure cleaner came out, even the little idle holes. What made me think its running dry is the bottom carb the two brass vertical tubes (don't know their specific name) when running spray gas, where the top one does not.

Put it all back together, primed, cranked and cranked and cranked and nothing. Cranked once more and with one shot of ether she took off and stayed on. Like i said about the two brass vertical tubes, still applies, bottom one is spraying, top one is not. But, it stays running now, and i can shut it down and start it back up. Idles like before, like crap. With that, i can go along with an ignition problem, though i might have good spark, i can hear it missing, rev up and cough, rev up and cough.

Still don't think those carbs are quite right yet either...

I'd like to just buy all new coils and plug wires and cdi but i'm still worried about spending any more cash on it if that #1 cylinder is going to junk out on me.

 

[keefallan]

Quick question. Have you done a compression check? That hasn't been mentioned yet. If the carb is working (yet fuel isn't pulled out into the motor), then you may have have a compression problem. Don't quote me on this. But I believe you need compression to be able to create the vacuum to pull the fuel out of the carbs! If I'm wrong in this, someone will clear the air on it. But if I remember right, you need compression for proper carb function.

 

[SigSaurP229]

First off don't use ether/starting fluid it provides no lubrication to your cylinders and is very bad for your outboard. Get an old windex bottle or something fill it with 50:1 gas oil mix, and use that in place of starting fluid.

You didn't mention what year this is or provide a model/serial number.

If it continued running after you spray gas oil in the cylinders then you need to check the Choke/Or primer solenoid depending on the year.

 

[greghennings]

First off don't use ether/starting fluid it provides no lubrication to your cylinders and is very bad for your outboard. Get an old windex bottle or something fill it with 50:1 gas oil mix, and use that in place of starting fluid.

You didn't mention what year this is or provide a model/serial number.

If it continued running after you spray gas oil in the cylinders then you need to check the Choke/Or primer solenoid depending on the year.

Thanks for the tip, i will definitely get a squirt bottle and put gas in it, the starting fluid i have claims to have "upper cylinder lubrication", but your way would be way better. Thanks to having my original thread deleted, all the stats of my situation are gone. its a 1978 motor. compression was 95-105-105-105. choke works. through more carb cleaning i was able to get the top cylinder to produce some gas. it runs sort of ok. but as before, won't start without some means of direct injection of fuel. after that the carbs take over, maybe just the way its going to be?

 

[masterbt]

if the difference is15psi between two cyl. then you have problem. when you take compression have throttle w/o.

 

[SigSaurP229]

You are within 10% PSI compression on all 4 so I don't think compression would be a problem on it. Have you link and synced the timing? Does the primer bulb pump up hard?

 

[emdsapmgr]

Normal factory compression on that engine when new is in the 125 lbs per cyl, so your engine is down on compression somewhat. So it will be down on hp as you run it. (A treatment of Bombardier Engine Tuner is advisable. You may get the compression up somewhat as a result.) Keep in mind, if one carb is not supplying enough fuel, it is also not supplying enough oil. So, make sure you resolve the fuel issue to all cyls before you leave your troubleshooting mode and take it to the water for the day. When you had the carbs apart, did you pull the high speed jets out for a visual inspection? If that top carb is a problem, you might just want to replace it. Have to be many of these old crossflow carbs in marine salvage yards across the US. Sometimes you can get a deal on a matching pair.

 

[SigSaurP229]

I wouldn't sweat the compression just yet. First thing start with your fuel issues if its coughing and sneezing and u have spark the u have a fuel issue. Pull the jets clean them with a piece of single strand wire pull the idle orifice tubes and clean underneath them. Pull all of the fuel lines and check for deteriation in all the lines. You are running it on non ethanol gas correct

 

[greghennings]

I would like to have posted earlier but this site is still so buggy it wouldn't let me.

I took apart the carbs and cleaned out the high speed jets this weekend and she runs a bit better, i have fuel coming up the top carb now at least. I have spark, that does jump the 7/16, but i know the power pack and ignition coils on the 2/4 side are original and i'm replacing them just to cross that off my list. I also did a decarb with Seafoam, magical stuff, it didn't take long after running that through it and having it sit over night full of it to really clean it out, runs decent now, i need to get my idle down though, hangs out at 1000-1100, i think simply tweaking my throttle cable and throttle stop screw will fix that. It does have a misfire in it, hoping the new ignition parts will clear that up. My throttle plates are synced up, i do need to adjust my choke a little, i don't think its closing completely. I'll fix most of this saturday.

Problem here is i can only get 87 octane regular unleaded, 87 octane e-10, or 92 octane e-10. My boat motors have always run better on the higher octane, and that's what i was recommend to use. where i fish in MN i can get and use 93 octane regular. Perhaps i need to be buying the 87 regular and adding an octane booster?

 

[greghennings]

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