Gunk piled up on spark plug J150

[jwellcraft]

I was checking my spark plugs today after I went fishing yesterday because I noticed after the trip my motor had some smut marks on a couple spots. I pulled the #1 spark plug on the starboard side and I don't know what it is but it is piled tight in the spark plug and its black but when I scrape a piece off of it is white underneath (possibly carbon but looks like salt as well). This is the second time I have noticed this and I have checked the compression and it has 120psi in this cylinder and all the other plugs were clean (some blackness but not chunks of gunk like this one). These plugs are about 5 months old and maybe 8 full days out on them. What could this gunk be and what could cause this? The motor is a 1994 Johnson 150 EXERV. Started fine and ran good that day and still does.

 

[Dhadley]

Re: Gunk piled up on spark plug J150

What brand / number plugs are they?

 

[jwellcraft]

Re: Gunk piled up on spark plug J150

They came from the dealer and they are Champion 5828.

 

[Faztbullet]

Re: Gunk piled up on spark plug J150

Wrong plugs...should be the QL78YC not the L77J4C's. Also from your avatar it looks like you operate in brackish/salt water. If this is the case I would service the T-stats as a engine running to cold(t-stat hung open) will cause excess carbon problems..

 

[jwellcraft]

Re: Gunk piled up on spark plug J150

Ok the dealer counldn't figure out the year of the motor because the previous owner painted over the model number tag and I couldn't either so I cleaned the area and found the model which gave me the year and the other details. I will go and get these plugs today and about the t-stats they are brand new only 2 month old. Check them regularly and they keep clean and yes I am in a salt water area. Why I think all of this carbon is coming up now is because the previous owner ran this motor without s-stats so it was always in a cold loop I guess. Thanks

 

[Faztbullet]

Re: Gunk piled up on spark plug J150

If it was in my shop I would: Decarbon it with Mercury power tune overnight,and Brp Carbon guard or Merc Quickleen to fuel and a few high speed runs. Make sure engine is operating in the proper rpm range and not being lugged by being overpropped.

 

[jwellcraft]

Re: Gunk piled up on spark plug J150

These champion 5828 spark plugs are the same as the QL77JC4's which is called for by the manufacturer. Are the QL78YC's any deeper and are these a hotter plug or cooler? I would hate to use the wrong plugs in this and end up with a damaged motor.

 

[tashasdaddy]

Re: Gunk piled up on spark plug J150

the chart calls for QL78YC

http://www.docstoc.com/docs/4877037/Spark-Plug-Application-Chart-for-Evinrude-Johnson-Outboards-thru

 

[jwellcraft]

Re: Gunk piled up on spark plug J150

Ok but if you go to any Johnson parts store and type in my details (1994 Johnson 150 EXERV) it has QL77JC4 or optional QL16V so I don't know why this is all different. I trust you guys and will get these other plugs but why if this is changed it hasn't been updated to reflect the change.

 

[jwellcraft]

Re: Gunk piled up on spark plug J150

Prior to installing these new plugs (QL78YC) I am going to run some engine tuner through it to hopefully clean out all that carbon so is one can of the engine tuner enough?

 

[ezeke]

Re: Gunk piled up on spark plug J150

What any authorized BRP dealer has on his chart is what shows in the thumbnail.

http://www.maxrules.com/OMCplugchart.html

http://continuouswave.com/whaler/reference/BRP/SparkPlugChart2008.pdf

 

[jwellcraft]

Re: Gunk piled up on spark plug J150

Yes thanks, I have seen these charts around but my factory manual P/N 500611 says the recommended plug for my J150EXERV is QL77JC4.

 

[jwellcraft]

Re: Gunk piled up on spark plug J150

Hi guys just to let you know since I have installed these new plugs 78YC's for the 2 days they have been in my motor runs like crap and it is very hard to start. Not sure if it's becuase initially the motor got flooded when I forgot to return the throttle back to idle after I was doing a compression check but it has started since and I ran for a while and gave it some nice revs and wiped the plugs off and attempted to start the next day and nothing..just rolling and rolling and when it did start the engine had a puff of smoke just about for the whole time it was running (10 mins on the hose). My 77JC4's never did that.

 

[CharlieB]

Re: Gunk piled up on spark plug J150

I'm sure one of the guys will soon look up your model #

In the mean time, just for giggles, can you look at your motor from the top, and guesstimate the angle of the cyl banks, i.e., is this a 60 degree Vee or a 90 degree Vee?

 

[jwellcraft]

Re: Gunk piled up on spark plug J150

Took the boat out again today and did an all day fishing trip (28 miles) and when I was home after flushing the motor I checked the plugs (78YC's) and the starboard #1 cylinder had loads of what looks to be carbon packed on the tip again and so much that you couldn't see the tip and that end of the plug looked round like a black ball was stuck on it. The others were normal with slight blackness but no build up. There must be a carburetor issue now or something but starts fine idles fine and runs pretty strong for it's age. I will try and attach a pic of the plug later.

 

[Dhadley]

Re: Gunk piled up on spark plug J150

The 78YC is just a bit hotter than the 77JC4 and a longer reach plug. Either will be fine in a 60* looper. "Gunk" build up on #1 plug may, possibly, indicate a water leak. the early 60* blocks had an issue with a glue seam leak in the casting which showed up on the #1 cylinder.

 

[jwellcraft]

Re: Gunk piled up on spark plug J150

Ok thanks and if so there is a leak in the casting, how can this be repaired or does it have to be replaced?

 

[Faztbullet]

Re: Gunk piled up on spark plug J150

It can be pressure tested to check for leakage but to repair requires engine to be torn down,sleeve removed,cylinder welded and remachined,new sleeve installed and engine reassembled. Usually if it is leaking you will have: steamed cleaned piston and plug, miss at mid rangeand sometime a knock at midrange rpm. Post a picture of plug so we can see if carbon or aluminum fouling, if carbon it could be a weak coil,fuel or pack problem on that cylinder...

 

[jwellcraft]

Re: Gunk piled up on spark plug J150

Ok the here is a pic of the 77JC4 and 3 of the 78YC's

 

[CatTwentyTwo]

Re: Gunk piled up on spark plug J150

Good lord, that plugs a mess. I have a 94 175 and can't wait to here what the experts here think what the cause might be.