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Glow plugs burning out fast and black??

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Glow plugs burning out fast and black??

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Old 05-12-2018, 03:28 PM
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Default Glow plugs burning out fast and black??

Hi there...Any comments on why my plugs keep burning like this after 5-7 litres of fuel?
seems black and like some sort of build up...but would like to know if its either too rich or too lean?

thanks!!
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Old 05-12-2018, 03:56 PM
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what motor, fuel nitro %, plug?. If you are to lean the coil will be slightly distorted or pulled. whats the head clearance? any detonation signs on top of piston?
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Old 05-12-2018, 04:17 PM
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Looks like detonation combined with poor fuel. Too lean and use better fuel.
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Old 05-12-2018, 04:49 PM
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Could also be a too low head clearance for the used nitro percentage
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Old 05-13-2018, 12:21 AM
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Originally Posted by Propchecku37 View Post
what motor, fuel nitro %, plug?. If you are to lean the coil will be slightly distorted or pulled. whats the head clearance? any detonation signs on top of piston?
BLOK .21 aM, Thor fuel (25%), o.s 2090 pipe, o.s p3 plug

going to tear down now with more pics to follow, appreciate the replies guys!
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Old 05-13-2018, 06:00 AM
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There’s half your problem. A P3 plug is too damn hot!
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Old 05-13-2018, 12:13 PM
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We run P3 year round..

Try different fuel and have someone help you tune it.
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Old 05-13-2018, 02:37 PM
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Originally Posted by MaricopaAgent View Post
We run P3 year round..

Try different fuel and have someone help you tune it.
It depends on the humidity and temperature where you are located. We have to run p4 in higher humidity or we will. Be replacing glow plugs every other heat. That is why tuning settings etc should not be copied from the web because there are too many other variables that come into play. Fuel, temp, humidity, elevation, plug, etc. most people never put all that info out there.
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Old 05-14-2018, 01:29 AM
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ok so took off the head and noticed that all screws were very very loose, could have used two fingers to loosen

I will completely tear down clean up and rebuild but i wanted to confirm that the loose head was my problem here...

Any suggestions/diagnostics would be greatly appreciated...

thanks guys
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Old 05-14-2018, 01:32 AM
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before cleaning













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Old 05-14-2018, 01:35 AM
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after cleaning out with fuel, toothbrush and paper towel...













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Old 05-14-2018, 04:38 AM
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Detonation. Too lean, too much Nitro combined with too hot a glow plug, too tight of squish clearance. Very much likely too lean is the main culprit. That’s the problem you face when using an ultra hot glow plug and 25-30% Nitro. Gotta run sloppy rich to keep the plug doused and cooled off. Run a colder plug.
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Old 05-14-2018, 07:40 PM
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That's a ton of build up, wow. Does that fuel contain a lot of castor? Run a different fuel for sure!

Edit: Also, a worn out/stretched connecting rod will kill glow plugs like nobody's business. Another thing to consider.
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Old 05-14-2018, 08:33 PM
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Originally Posted by timjs View Post
That's a ton of build up, wow. Does that fuel contain a lot of castor? Run a different fuel for sure!

Edit: Also, a worn out/stretched connecting rod will kill glow plugs like nobody's business. Another thing to consider.
A full castor oil package won’t burn like that. I know that for a fact.
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Old 05-15-2018, 12:08 AM
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if you change fuel and no differnt. id be looking at dirt...
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