Glow plug lasting less than one tank?

[Nubster]

I broke in my XTM 24/7 about a month ago and did so with the glowplug that came in the motor. Then I picked up a couple McCoy MC9 at my local shop. Well, about a week ago I am tuning and my truck seems to be running decent except for a hard start problem but in less than a tank, the plug is toast. By this time I have already busted a shock and tower so I call it a day. Well this afternoon, go out and after some effort get it running and the truck is screeming. I stop it to do some trim adjustments on my Tx and then it won't fire back up. Plug is dead. So what is the deal? I am using Byrons 20% and pretty sure I am not too rich and have good smoke so I am not too lean either. Is there a secret to these things. At almost $6 a pop, I can't afford to keep running at this pace.

 

[Monkey Wrench]

MC-9's, if memory serves correctly (and Olds is the real expert on this) is a cold plug intended for running 30% or higher. Maybe try a McCoy MC-59 plug next go around.

 

[Arrow]

you could have a lean low or a lean high... so its giving you a false sense of smoke..

my first engine ever was a novarossi and i had a lean low end but didnt know it. morphed the sleeve and trashed it =\

anyways thats what I'm thinking... but my engine tuning isnt all that great

 

[Nubster]

So how can I tell? Temps stay in the mid 200's no higher than 275.

 

[Buggyracer28]

Well, try richening out your high end for now. 275* is a little high if you're wanting to try and save plugs. My Novarossi BS21SB burned $35 worth of plugs in a total of 4 tanks. I realized that there was a crack in the crankcase under the engine mount wchich was causing the plug to die at a certain rpm.

Check for airleaks, cracks, and bad seals. Check your tank, crankcase, carb, backplate and your fuel lines. Hopefully this might solve the problem. But deffinitally tone down your high and maybe your low end for now.

 

[olds97_lss]

What does the plug look like? Is the coil broken? Is the coil compressed? Is the end of the plug shiny or black?

 

[Nubster]

Buggy, will do. I'll make sure to keep temps down some and also check for leaks.

olds, the plug ends are still shiny I think as they don't have time to discolor. Of coarse the one I used to breakin with is black. Coil not broken, not sure about compressed. I am at work now but will take a look at them later and try to get some pics up so maybe that will help some.

 

[olds97_lss]

Look for the coil to be deformed or compressed. If it's not broken, then why won't it light?

 

[Nubster]

I dunno. I know the coil is still there and appears to be intact. Maybe broken up inside?

 

[olds97_lss]

I never had that good of luck with the McCoy plugs... they never lasted long for me and didn't run well.

Maybe try an OS #8. A medium plug should work with that engine and fuel that your running.

 

[NvNitro]

MC-9's, if memory serves correctly (and Olds is the real expert on this) is a cold plug intended for running 30% or higher. Maybe try a McCoy MC-59 plug next go around.

You are correct on that MW. MC-9 is a cold plug. I found out the hard way today. Stick with the MC-59. So far the MC's have been a good plug for me.

 

[Nubster]

Yeah, got a couple 59's and so far so good. Ran three tanks about a week ago and all was good. Plug is still firing so it should be good for some more action. I also finally found that XTM recommends the 59 for the 24.7 motor.