Spark Plug keeps changing gap??

[Doeun_k]

hey hawkers,
i was wondering why my spark plugs keep changing gap when the 9.9hp outboard engine starts?? i have to keep adjusting the gap everytime i use it??

do i need new spark plugs? are they the wrong spark plugs? or is there something in the motor that pushes the gap back?

thanks,

chen k

[cprince]

Yup. Pistons.

Ouch!!

Craig

[Doeun_k]

any way to prevent that??or fix it my self??

Chen K

[cprince]

What model plugs?
What model and year is the motor?
2 or 4 stk?

The gap, I would assume, is getting smaller?

It is possible that the plugs, if they were new, were the wrong ones; too long... perhaps they went into the cylinder too deep and the piston heads are now hitting them.

Do not try running the motor again until this is fixed. If what I am guessing is going on is correct, this can cause serious damage to your pistons.

Do you have a compression tester?

Craig

[Doeun_k]

nope don't know much about motors but i guess ill try to get new ones, and its a 2 stroke engine made in 1969, ill try new plugs

thanks for the head up

Chen K

[cprince]

nope don't know much about motors but i guess ill try to get new ones, and its a 2 stroke engine made in 1969, ill try new plugs

thanks for the head up

Chen K

What model engine? I could find the exact model plug that it would need. The other thing that it could be, especially due to it's age, is carbon buildup.

De-carb'ing an engine is not too difficult.

Here are some directions that is the general procedure I have used.

-- ----------------------
First you need a separate small fuel tank. One of those 3 gal red Tempos works great or an empty gal milk jug will also work, but might be a bit messier..

I use Seafoam over the OEM stuff like OMC Engine Tuner or Merc Power Tune because in the last few years they changed the formula and you have to let them sit up 12 hours. Who's got time for that?? Seafoam you can buy from NAPA, CarQuest or other auto stores. Seafoam works in 15 mins.

You'll need 3/4 gal of gasoline and one 16oz can of seafoam for each engine. Don't forget to add 3oz of oil if you are premixing in a carbed engine. Use about 3 ft piece of fuel hose off the little tank. You connect this tank to your engine by pulling off the main tank fuel hose off the intake side of your water separating fuel filter and plug the hose off the small tank on to that fitting. Or you can separate the fuel line on the tank side primer ball, so you can still use your primer. If you have an engine that has fuel plug then you need a fuel plug on the little tanks hose.

Start the engine, let it warm up and start pulling the mix into the engine. You may have to increase the idle to keep it running once she get loaded with the Seafoam. Run the engine 15 mins in the dock or just cruising around under 2500. Then shut it down and let it sit for 15 mins. Restart the engine, the smoke you see is the carbon burning off. Do the whole thing again and let her sit again for 15 mins. If she smokes after the second time do it again, but I've never seen one still smoke after three doses. The gallon mix should be enough to do this 3 times. You don't need any wide open throttle, you don't need to change the plugs. If it's cleaning the combustion chambers it's also cleaning the plugs, but every 50-60hrs is good time to change plugs in most engines.

I cleaned a antique evinrude one time that had a 1/4" of solid carbon on the exhaust chamber walls by running a 1/2 gal of the mix through it. Seafoam has been around since the 30's and it's what they used when they were burning straight 4 stroke 40SAE oils in outboards.

You guys with the 4 strokes think you are immune from this? Those engines work 10 times as hard as any auto engine ever will and they will carbon up. I bought a Bronco two years ago that had 95,000 miles on it. When I used seafoam on it I had the neighbors hanging out of their front doors looking for where the fire was after I started it the first time there so much smoke.

Too many are under the assumption that it's totally the 2 stroke oil that causes the carbon, Wrong... it's also the additives they put in the fuels today. The carbon inhibitors in 2 stroke oil are there for this reason also. Remember when gasoline used to smell like gasoline, today it smells more like bad cologne.

For those guys that like to do the carbon treatment by spraying it down the carbs Seafoam also comes in spray can called Deep Creep. It's the same stuff under pressure. Says right on the can Oxygen Sensor Safe, for you Yam guys.

After that if your engine maunf recommends a daily additive treatment then do that in the mean time, but all 2 stroke outboard need decarboned every 50-60hrs. If I owned a 4 stroke I would do it the same. Once you are set up with the tank and hose the Seafoam is only 5-6 bucks can. It to easy not to do it
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Give this a try!

Craig

[Doeun_k]

i will definately give seafoam a try, but i think im goin g to have to change the plugs, i pulled them out and there was a tiny bit of rubbing on the ends of the plugs, then i will do the seafoam thing to it, but my motor is an old 1969 evinrude 9.5hp, but for sure i will do that.

Thanks for the advice,

Chen K

[plncrzy]

i will definately give seafoam a try, but i think im goin g to have to change the plugs, i pulled them out and there was a tiny bit of rubbing on the ends of the plugs, then i will do the seafoam thing to it, but my motor is an old 1969 evinrude 9.5hp, but for sure i will do that.

Thanks for the advice,

Chen K

make sure its a champion J4C or equivalent with a gap of .030

[FishToLive]

Can we do the seafoam treatment with the motor in a barrel filled with water?

[cprince]

Can we do the seafoam treatment with the motor in a barrel filled with water?

That is how I do it. It might not be practical if you have too big of a motor... they sell those suction cup brackets with a hose attachment so you can run without being in a barrel or in the water. I have seen two sizes at Canadian Tire and they are about $10 to $20.

Just be careful around the prop if you put it in gear!!!!

Craig

[Doeun_k]

so i had a fellow worker fix up my plugs at work and he made washers for me so i would have to get new plugs yet cus he said there pretty new, so now all i got to do is get the seafoam.

Thanks Cprince

Chen K

[cprince]

so i had a fellow worker fix up my plugs at work and he made washers for me so i would have to get new plugs yet cus he said there pretty new, so now all i got to do is get the seafoam.

Thanks Cprince

Chen K

Good news!

Just be careful if they are the wrong plugs, the spark may be too hot and cause what it called "Pre-Detonation" messing up your timing making the motor run like garbage.

If they are too cold, your combustion will be insufficient and the plugs will get fouled up quite quickly and the motor will misfire and leave you dead in the water.

Both of these thing *could* cause engine failure. I don't want to fear monger and dramatize the effects of having the wrong plugs, but you need to know the possible consequences.

Then again, it is just as possible that the plug you have is the right temperature!

Craig

[crankbearing]

If you just get the right short reach plugs for the motor the problem will be gone. You don't need to index (space them with washers) plugs in a fishing motor. I only index plugs in racing engines that I have decked or in a Early Mercury's case squished block is the term.

If NGK Plugs the lower the number the hotter the plug and champion are opposite. So IE if your motor called for NGK B6S (HOT plug) or B7S (colder plug) and you install B6HS or B7HS then you have 1/2" reach instead of 3/8" reach.

Tell me what size motor you have and what make and I will tell you which plugs you need.

Regards.

Dave

[Doeun_k]

hey,
my model is 1969 Evinrude 9.5 HP Model# 9922S , i think im going to need some new plugs, i brough my motor out for a test run but it runs fine until it get a little hot then the power cuts off a bit, im guessing its just the plugs that are getting too hot, can you help my out by telling me the right plugs?

Thanks,
Chen K

[crankbearing]

HI Chen,

Your motor takes

Champion J4J Spark Plugs as stock This number also converts to a
NGK B7S. Those are the plugs you need, you do not want any other letters or numbers in the plug description. Any Benson Auto Parts will be able to get THOSE plugs for you if not let me know.

Loosing power when hot could be a number of things like ignition breaking down, Fuel Starvation and more but the right plugs are good place to start. Those motors have minimal compression to start with so making them work harder with the wrong plugs is not a good thing.

regards,

Dave