Stuck Plug
May 26, 2000 | 11:51 PM
#2
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Joined: Jul 1999
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I'm afraid that you may have to pull your cylinder head off. There may be carbon build up on the threads the spark plug. Sometimes for various reasons spark plugs can have 2 or 3 threads showing on the combustion chamber side the head, carbon builds up over time and then prevents it's removal.
If there's carbon built up, you'll have to remove your cylinder head, remove the offending build-up and then take the plug out. I'd be cautious here, because the carbon can and will come thru with the spark plug and it will wipe out the threads in the hole. Which would require quite a bit of rework to get it functioning again.
There also may dissimilar metal corrosion and your plug has corroded and now is stuck as well. The cylinder head is aluminum, the plug is cadmium plated steel. The cad plating is the sacrificial coating, it's meant to act as a barrier and ultimately be consumed by any corrosive forces before the base metal. It also has less "dissimilarities" with the aluminum, therefore it reacts slower the the different metal(anode and cathode effect) If corrosion is the case, it could get interesting....The only reccomendation that I have there is liberal use of penetrating oil, perhaps a little heat and crossed fingers.
Some tech tips concerning plugs:
1) Coat the threads of your plug with anti-sieze. This prevents galling and will help keep the dissimilar metal corrosion at bay a bit too. This is especially important on 4 strokes that may not see the plug's removal as often as on a 2 stroke.
2) Don't overtighten the plug, snug is sufficient, the crush washer on the plug seals and provides locking features as well.
3)Always gap them to the proper spec. Most common plugs, like B8,B9 ES's come around .030" whereas the required gap can be as low as .018"(which suprised the hell outta me that my snowmobile was that tight)
4) Replace them often. Don't buy your plugs from the bike shop. Too expensive. Most "brand-name" parts stores stock them and typically are about a dollar cheaper. Spark plugs are consumable items, they simply wear out.(Higher resistance over time, eroded electrodes, etc.)
Sorry for the bad news, but I think it would be safest to pull the head and get a look-see at the other side first...
[red]Good luck!!![/red]
If there's carbon built up, you'll have to remove your cylinder head, remove the offending build-up and then take the plug out. I'd be cautious here, because the carbon can and will come thru with the spark plug and it will wipe out the threads in the hole. Which would require quite a bit of rework to get it functioning again.
There also may dissimilar metal corrosion and your plug has corroded and now is stuck as well. The cylinder head is aluminum, the plug is cadmium plated steel. The cad plating is the sacrificial coating, it's meant to act as a barrier and ultimately be consumed by any corrosive forces before the base metal. It also has less "dissimilarities" with the aluminum, therefore it reacts slower the the different metal(anode and cathode effect) If corrosion is the case, it could get interesting....The only reccomendation that I have there is liberal use of penetrating oil, perhaps a little heat and crossed fingers.
Some tech tips concerning plugs:
1) Coat the threads of your plug with anti-sieze. This prevents galling and will help keep the dissimilar metal corrosion at bay a bit too. This is especially important on 4 strokes that may not see the plug's removal as often as on a 2 stroke.
2) Don't overtighten the plug, snug is sufficient, the crush washer on the plug seals and provides locking features as well.
3)Always gap them to the proper spec. Most common plugs, like B8,B9 ES's come around .030" whereas the required gap can be as low as .018"(which suprised the hell outta me that my snowmobile was that tight)
4) Replace them often. Don't buy your plugs from the bike shop. Too expensive. Most "brand-name" parts stores stock them and typically are about a dollar cheaper. Spark plugs are consumable items, they simply wear out.(Higher resistance over time, eroded electrodes, etc.)
Sorry for the bad news, but I think it would be safest to pull the head and get a look-see at the other side first...
[red]Good luck!!![/red]
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