bspate

Another cause of going through multiple glow plugs within a few tanks is when the filament of the first glow plug breaks off. It then stays in the engine and those pieces continue to hit the filament on the new plugs causing them to be destroyed. The way to see if this is happening is take off the cooling head and look at the top of the piston for damage from the broken filaments being squished between the head and piston. The damage will be visible on top of the piston and the sides of it.

Anytime you have a glow plug fail, make sure you look at the filament closely before tossing it to make sure it is all there. If you can tell some of it is missing, then it is a good idea to turn the vehicle upside down and spray WD-40 in the glow plug hole to try and get some of the debris out. This does the same type of damage as if some big pieces of sand get past your air filter........not good!! []

- bspate -

sillyrabbit72

maybeits just me but it sounds like you engine is running way hot i mean 247!!! according to "the ultimate nitro engine guide it should ever get above 212!!!!
if it does you do some major damage to the engine. the perfect temperature is supposed to be between 200-212!!!
your temps might just be running way high which is causing all the plug probs. see if you can get it down to about 200-212 and see if that works.

hope this helps!!!

trackman

no such thing as a perfect temperature.

sillyrabbit72

sorry wrong wording i meant optimum temperature for maximum life and performance

RLMHPI

I have never read or followed any engine tuning book!!!! In real life 200f-212f is way too cool I have owned multiple engines and have ran all of them between 240f and 280f with great success anything over 300f is too high for most guys i know. I personally like to keep it under 260f. If you want to run them at such low temps they are not going to be very fast being so rich. My original savage engine going through very thick grass and agressive offroad terrain hit 290f + temps and is on its 9th gallon!!!

sillyrabbit72

all i was doing was quoting the book just thought i would try to help

RLMHPI

It seemed from what you wrote that you were not just quoting a book you said 247 was "way hot" but I understand your point any help is always good just burn that page in that book that says 200-212!!!! Just Kidding

mozzzy_2000

247F hot? My engines will run 220F on day and as much as 280F the next depending on the weather. Its been said time & time again, never tune to a temp.
on the topic though, I reckon the mc9 is too cold for 20%. try the Mc8 or the Mc59. Its likely that you are either too lean or too rich or any of the above mentioned..

Da Smak

Shim, rofl, this is nothing more than an overlean engine, depending on your air temp where you are I'd say your engie is running too hot (too lean).

RLMHPI

I wonder if the guy with the original glow plug problem is alive he has not responded I hate when people start a thread with a problem and never reply with input on how they fixed it!!!