Evinrude 1979 ? 9.9 bottom plug won?t fire

[Rick.]

Hello all. Just spent a frustrating afternoon and don?t understand what?s wrong. This motor is new to me and I spent the winter bringing it back to life. As of February I had it running like a top and waiting for ice off to make final adjustments.
Finally got it out last week it ran like a dog. Would not get up to speed and seemed like there was just no power. Aso would not idle. I kind of thought the fuel pump might be week. Today at the shop I:
- Pulled the carb. and re-cleaned it. Installed kit in Jan.
- Checked for spark and was present on both cylinders
- Did spark quality check and get nice blue snappy spark jumping 3/8 in.
- Checked comp. 92 on top and 95 on bottom.
- Cleaned all ignition coil terminals.
- Used fresh gas mix.
Well I could get it to rev. but not idle. Finally I pulled the plug wires one at a time and found the bottom cylinder was not firing even though I have excellent spark to the plug. I put a new plug in and same deal. When I pulled the new plug it was wet but also had a light gray oily build up around the insulator. I?m thinking the head gasket may be leaking water and fouling the plug but I?m not sure and though I would ask for advice on where to go from here. If the head gasket is the problem wouldn?t my compression be much lower on the leaky cylinder? As always, thanks for any help and/or suggestions. Rick.

 

[o/b tech]

Re: Evinrude 1979 ? 9.9 bottom plug won?t fire

Yes there may be water getting into the cylinder. two possible causes are from either the head gasket and or exhaust cover gaskets. Either way not a good sign that the insulator is gey in colour. May want to pull off head and visualy inspect cylinder for scoring. Also if you remove exhaust cover you can see the side of the piston for any scoring as well. Both the head and exhaust cover can loose clamp over time.

 

[Rick.]

Re: Evinrude 1979 ? 9.9 bottom plug won?t fire

Thanks o/b tech: Next question. Would it make more sense water is coming in through the exhaust due to the compression numbers being good? I failed to mention I also hooked a hose up to the water tube (with the leg off) earlier this afternoon because I had no water coming out the pee hole. Maybe too much pressure for the gasket? I have a new impeller in it and something did come out the pee hole with the hose pressure and it worked fine after that. I did continually check for temp. and it never got hot just the pee hole line was plugged. I should also add I never saw very much exhaust (bubbles) coming up from the prop. It seemed all the exhaust was coming out the hole at the back of the leg. Rick.

 

[tashasdaddy]

Re: Evinrude 1979 ? 9.9 bottom plug won?t fire

Rick check it in darker place, spark could be arching to the block, with a bad plug wire.

 

[Rick.]

Re: Evinrude 1979 ? 9.9 bottom plug won?t fire

Thanks for the advice so far. Here is some more information I got today.

I did check for arching spark and found it. These plug wires are part of the ignition coils and can't be replaced separately. I taped them for now and that stopped the arching. When plug boots are pulled, spark will jump more than half an inch back to the plug terminal. Still no fire on bottom plug though. The plug was milky wet so I pulled the head and there was a fare amount of oil/water mix in the cylinder. The cylinder wall was very smooth with no scratches or marks at all. There was a bit of piston slap side to side but no play at all up or down. I could not see an obvious leak on the gasket. I did sand the head on glass backer and it appears the highest spot, where most metal sanded down, was the spot between the lower cylinder and the water raceway. So........., what would your recommendations be for the next step? I'm thinking a new head gasket and see if that works to stop the water intrusion. Thanks so much. Rick.
EDIT: I also checked torque on exhaust cover bolts and all (I could reach) were tight.

 

[tx1961whaler]

Re: Evinrude 1979 ? 9.9 bottom plug won?t fire

Put the new head gasket on, torque it right, and fire it up!
Make sure to re-torque it after you've run it.

 

[Rick.]

Re: Evinrude 1979 ? 9.9 bottom plug won?t fire

I picked up a new head gasket today. I know the torque # and sequence from my manual. Should I use anything on the bolts and/or gasket sealer on the head? Flames on T.V. tonight, Go Flames Go!!! Thanks, Rick.

 

[o/b tech]

Re: Evinrude 1979 ? 9.9 bottom plug won?t fire

No gasket sealer needed on the new head gasket and the bolts can go on dry. Hopefully this eliminates the water getting into the cylinder. How was the exhaust cover gaskets and were they checked. The reason why the spark was jumping was prob due to the plug being wetted out and spark choosing the easiest path to ground if not thru the plug. Good luck.

 

[Rick.]

Re: Evinrude 1979 ? 9.9 bottom plug won?t fire

I didn't pull the exhaust cover. I did check the bolts that were easiest to get at and they were tight. I'll do the head gasket first and hope it is the culprit..Thanks, Rick.

 

[Rick.]

Re: Evinrude 1979 ? 9.9 bottom plug won?t fire

Well I replaced the head gasket and still no fire on bottom plug. Pulled the plug and still getting water/gas/oil mix on the plug. So the next step is a gasket set on the exhaust cover? Thanks for any suggestions/encouragement. Rick.

 

[o/b tech]

Re: Evinrude 1979 ? 9.9 bottom plug won?t fire

Good luck and would like to hear how it turns out.

 

[Rick.]

Re: Evinrude 1979 ? 9.9 bottom plug won?t fire

I'm ready to put in new gaskets on theexhaust covers and wonder if sealant is required? The book said to use sealant but doesn't say what to use. Thanks, Rick.