Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines
The Regular Stuff: Chat, Buy, Sell, Off Topic, etc. => General Discussion - Scale Model Gas Engines - Hit & Miss - Throttle Governed - Non-Compression – etc => Topic started by: Belugawhaleman on January 18, 2020, 05:10:47 pm
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Hi Paul,...about sparkplug cleaning...i clean the plug with a small "acid" non-metallic semi-stiff brush using carb & fuel injector cleaner spray bath. Then after compressed air blow out, i use my small Benz-O-matic pencil flame torch to carefully burn off any left on carbon residue. Comes out lookin like 99 % new ! ...just amazing what a little flame will glow & harmlessly burn off !...tom.
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Hi Paul,..as a M90 newbie (12-12-19)..a few thoughts...most normal sparkplugs are designed for gap tip operating temps around 700c (1300) degs F !! to promote self-cleaning of soot & other fouling electrode deposits by careful matching plug heat range to engine conditions. I don't think our o-ring'd M90's are running anywhere near that preferred sparkplug tip temps.There might be some soot reduction burn off effect if we could get the plug up to a higher temp by thermal insulating it with a nylon type washer (instead of the stock copper washer), thin thermal insulating paint coating on the sparkplug threads (leave a clean single turn for electrical contact) & replacing copper cyl head gasket with a suitable nylon thermal insulating type. This could also help get the valves & seats up to a better self-cleaning temp also. Btw...i never clean the sparkplug tip insulator with Anything Metallic (including brass, aluminum,etc) brush to avoid leaving permanent electrical conductive particle contamination !! If we're going to intentionally add oils to an otherwise near sootless burning clean naptha fuel (Coleman), we might as well help the sparkplug burn off as much needless wet crud as possible...just my newbie $00.03,..tom.
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Thanks for your replies.
I just cleaned my spark plug using a pipe cleaner and Easy- Off oven cleaner. It really seems to have worked.
After using the pipe cleaner as an applicator, I let the cleaner sit for a while. Then I scrubbed with the pipe cleaner.
The soot came off, bare metal was revealed. I then washed with dish soap. After rinsing I immersed the plug in meths. I dried the plug and reinstalled. The engine is running fine as I write this.
Paul
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Paul, a 5/16" or 8 mm deep socket both work fine.
A 5/16 or 8 mm open end wrench will also do the job if used with care not to bend valve stems.
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Hi Paul,..i played around with various
plug gaps today & my M90 "likes" the smaller .020" ( orig factory i think) gaps. ...tom.
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Thanks all for your replies.
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Hi Paul,...14-32 size spark plug gap specs seem to be seldom mentioned. I've seen 0.019" to whatever the engine wants by trial & test run & some just don't seem to care !....If you find something that works good, please let us know,..tom.
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Does anyone know, the correct gap?
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I use a small brass brush then a quick blast of Brake Clean,
The gap shouldn't change unless you drop the plug or have run it for hundreds of hours.
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Hi Paul
For cleaning the spark plug you can use a brass brush (like for guns).
For remove the plug you can also use 8mm Glow Plug Socket.
Found on internet :
https://www.idparts.com/glow-plug-socket-8mm-p-10539.html
Last year (with my model engineer friend Christian of Geneva) we bough the spark plugs "Rime fire VR 2 L"
Very good quality.
http://sparkplugs.morrisonandmarvin.com/14-32.php
With Aspen fuel the plug is not sooty.
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Hi.
Just removed my the plug from my horizontal hit miss engine. It was very sooty. I cleaned it up the
best I could and replaced . What is the best way to clean these little plugs?. What is the correct gap?
Where can I get a proper tool to remove the plug? Where can I get a replacement plug?
Thanks;
Paul the Belugawhaleman.