[SANDYM]

my glow plugs keep burning out does anyone know what could be the problem I was out today for about half hour doing fast runs checking my temp and i went through 3 plugs

[imported_revoracer]

what kinda of plug is it?? hot or cold plug ??

[plane_crazy]

Check the engine first. If the plugs you are using are the same as always then pull the backplate off and check the rod. If you detect wear, ie slop in the bushing then that is what could cause your plugs to go. Any small particles of aluminum or bronz will blow a plug. Otherwise start the engine with a rich top end then gradually lean in.

[Ozzker]

I was killing OS 8 plugs 1 every 15mins or less with my on-road, but then I switched to MC59 plugs, I found that they are alot cheaper, and after a quarter gallon, im still on my first one.

[tekno]

mcoy's are the best period. i like os n all but they tend to loose life fast and not perform well there also more expensive. mcoy's are cheaper last longer and and give the best performance bar none. I always use mcoys now and i love them.

[Pipeous]

McCoy and OS are totally different plugs too. McCoy are long, OS are short. OS8 are for large scale engines like airplanes and helis... and anyone that has used OS A3's will attest to them lasting forever. good sport plugs for engines designed to use OS plugs....

if your engine is designed to use OS plugs and you use a McCoy, then you should use 2 copper washers to get them the same depth...

[Gump]

if you're eating a plug every time you shut off your engine, you could have one or a combination of the following problems:
Sloppy conrod (at crankpin)
Worn or oval shaped crankpin
Bad rear bearing (excessive play)

Take apart your engine, clean out all oil residue and sludge with non-chlorinated brake cleaner (nitro cleaner) and check for play in the conrod, play in the bearing, and if you have a digital micrometre or vernier, measure the crankpin at many angles and see if its oval.

[imported_biggy boy]

My sons CEN GST 7.7 was burning plugs up real bad.
He took the back end of the motor off and found the crank pin where the connecting rod sits split in two, no wonder
motor is going back to Cen for warranty.

Glen