johnson 115 one cylinder down!!! no fire!!!

[JPGBU1]

ok.. long story short. I bought a whaler with a dead '78 115 evinrude 20" shaft. I get a 83 long shaft with about 20 hours on it.(true story) swapped power heads. big boom bang- running like a top and brand new. 17' over 50 mph... 3 hours in? instant- and I mean INSTANT loss of power. check the plugs. cylinder 4 is wet. hmmm.. ok, not a rook to engines, but am to more than 20hp 2 strokes. 454? all day. anyways- carbs had a nice varnish syrup in them from last run in 88... rebuilt them... bypass the vro (ran oil as well in fuel) trolling out and 4 is running like a top again but then loose #1. check compression- yes... 130 all around.(wot) check fuel- fine and dandy. wet plug... water? no. pulled head and the piston looks new! rings are fine- piston moves like it should- cylinder wall looks so smooth I said wow! back together, swap coils... ( have 2 spare heads for parts) still nothing on #4. 3 cylinders are running at 100% still hitting like 35. what the heck? soooo.... I have 4 spare power packs... next will swap it. hoping??? is it a timing issue on #4? fuel- compression- spark, but no fire. I am loosing it. what else could it be? would pay $100 for troubleshooting but I am over powered by 15 hp and no one will touch it. PS first time post... long time reader! you all rule!

 

[jtexas]

Re: johnson 115 one cylinder down!!! no fire!!!

You've ruled out the coil, that leaves stator, timer base and powerpack. My money's on the powerpack, and having a spare makes it easy to rule that out.

or if you prefer, www.outboardignition.com has ignition troubleshooting procedures, you'll need a DVA (direct voltage adapter) for your multimeter.

btw, if that motor was last run in 1988, you'll want to replace the water pump impeller if you haven't already.

 

[JPGBU1]

Re: johnson 115 one cylinder down!!! no fire!!!

Thanks! I did replace the water pump while rebuilding the 2 engines... I will try the power pack within 2 days and hopefully solve this delema. If not, I'll keep posting!!!

 

[JPGBU1]

Re: johnson 115 one cylinder down!!! no fire!!!

So, I have swapped the power pack and coils and still have good spark and compression, but when I pull the plug, no change, and still no power 1 cylinder. I guess tomorrow I am going to pull the top carb off again and re-go through it. I did not pull the freeze plugs when I rebuilt so I will go that agan. maybe I got something in it while rebuilding it? I don't know. I am getting frusterated however.... Any ideas??

 

[jtexas]

Re: johnson 115 one cylinder down!!! no fire!!!

ah, ok, when you said "no fire" I interpreted "no spark". sorry now I see where you said that in your original post. No point messing with coils and packs if you got spark.

So all that's left is fuel.

Is that carb spitting up fuel? Not the occasional droplet, I mean really spitting up...if so pull the reeds for inspection.

 

[emdsapmgr]

Re: johnson 115 one cylinder down!!! no fire!!!

Do you run a fuel filter on that engine? Pull out the high speed jet on the side of the carb that feeds #4 and see if there is any debris in it.

 

[JPGBU1]

Re: johnson 115 one cylinder down!!! no fire!!!

reeds on a 84 115? I didn't know there were reeds? where are they? is that the leaf plate?


all three cylinders that are running are spitting fuel when at 2400-3000 RPM you can see the splashing in the cylinder. the 1 cylinder with nothing I can see no splashing....

I am going to pull the carb and go through it completeley using comressed air and a nice full can of carb cleaner. I have spark and compression but no ignition of fuel. it's weird... compression and spark means usually fuel issue but I just broke down the carbs and it's now cylinder 1 not firing... before it was 4... I pulled the plug on #1 and no differance. used to be number 4 before rebuilding both carbs. and no i did not mix up the carbs... could the reeds cause this problem?

 

[jtexas]

Re: johnson 115 one cylinder down!!! no fire!!!

right, the leaf plate. Reeds are a defining feature of 2-stroke technology.

Honest with ya, I've never looked for spitting at higher than idle speed...I'm basically not qualified to diagnose a reed problem based solely on what you're saying there. I do know that it is normal (and expected) for fuel and oil to collect in the air silencer, that's the reason for the hose from airbox to crankcase.

That said, when reeds fail, they "fail to close" -- I don't believe they can "fail to open" if you know what I mean...so I'm certain that the lack of splashing in #1 is because there's no fuel going in, and since #2-#4 are hitting and #1 isn't, the reeds can't be causing your immediate symptoms. (Can't conclude the reeds are in perfect condition, just don't believe you need to go there now.) If my logic is flawed, I confident somebody who knows will jump in & correct me.

I'm guessing the #1 spark plug must be bone dry after idling?

Two top cyl are fed by the same carb, right? And there's only one idle jet on that carb?

Possibilities as I see 'em are:
1. Blockage in the idle passage between carb bowl and the back of the venturi *plus* a blockage in the hi-speed jet on that side.
2. Air leak somewhere on that side, prevents that piston from pulling enough vacuum to draw in fuel. Manifold gasket, carb mounting gasket, leaf plate gasket.
3. Something else I may never have heard of.

Have you tried spraying carb cleaner or premixed fuel around those gaskets, see if it gets sucked in?

Do you by any chance live in a region that only recently introduced ethanol-blended gasoline?

Hope this helps.......

 

[emdsapmgr]

Re: johnson 115 one cylinder down!!! no fire!!!

If you are not getting any fuel to one cylinder, you also are not getting any oil to that cyl either...

 

[JPGBU1]

Re: johnson 115 one cylinder down!!! no fire!!!

Thank you EVERYONE! for your imput and help. Bottom line is I am a dip-you know what...

I did a compression test of each cylinder to make sure there was little or no variance. 130 PSI on the dot every cylinder.

I pulled the carb again, dropped the bowl and there sat a piece of old melted rubber from the previous gasket right next to the jets... probably blocking every time there was fuel pull. It must had hid somewhere in the carb during the first rebuild. This time armed with a pancake compressor, I blew out every orafice, pulled the freeze plugs and covered the carb in cleaner. I also checked the reeds and they were beautiful and just like new. retighted the head bolts (as I replaced the head gaskets) and remounted everything back up. new plugs as well. Couple primer bulb squeezes hook up the ears and fires on the first revolution. idols like a champ. all plugs firing fine. drop her in the water- and punch it- nice clean full power and strenght.right up to WOT. 5200RPM I feel stupid but have learned a bunch and look forward to becomming an avid user of this forum!