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Old Nov 28, 2013, 06:44 AM
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Nav_Aids's Avatar
Canada, MB, Winnipeg
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reliable 1/4 x 32 Spark Plug

I'm converting some of my glow engines to spark and was wondering what's a good reliable 1/4 x 32 spark plug? Is the RCxel plug any good? Note: I don't want to break the bank on spark plugs but, I don't want to dead stick all the time either, I'm looking for a happy medium. Engine size is from 0.40 - 25cc.

Thanks
Ray
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Old Nov 28, 2013, 07:30 AM
Two left thumbs
Muncie, IN
Joined Sep 2006
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I only know of Rimfire plugs as an alternative, and they are spendy. http://sparkplugs.morrisonandmarvin.com/order.php

As for 25cc engines, all I've ever seen have 10mm or 14mm plugs, and are available from major manufacturers, thus inexpensive.
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Old Nov 28, 2013, 10:59 AM
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Joined Oct 2004
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Wow; never knew you could buy them with 6mm hex and 10-40 threads. That size should open up the possibility of sparking engines down to about 0.099 or so.
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Old Nov 28, 2013, 04:07 PM
I HATE GLOW PLUGS!
SrTelemaster's Avatar
United States, NY, St Lawrence
Joined Feb 2012
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I have had better service from the cheap $12 Made in China Plugs than the expensive Rimfires.

I buy them here. http://cncengines.com/orderpage.html
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Old Nov 28, 2013, 04:56 PM
I HATE GLOW PLUGS!
SrTelemaster's Avatar
United States, NY, St Lawrence
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Quote:
Originally Posted by GeoffinIN View Post
I only know of Rimfire plugs as an alternative, and they are spendy. http://sparkplugs.morrisonandmarvin.com/order.php
Those are pretty good prices for Rimfires.

I could use a few of the "long" 1/4'x32 plugs for my Saito FA91S & FA200Ti.
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Old Nov 29, 2013, 11:52 AM
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Nav_Aids's Avatar
Canada, MB, Winnipeg
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Quote:
Originally Posted by GeoffinIN View Post
I only know of Rimfire plugs as an alternative, and they are spendy. http://sparkplugs.morrisonandmarvin.com/order.php

As for 25cc engines, all I've ever seen have 10mm or 14mm plugs, and are available from major manufacturers, thus inexpensive.
I forgot to mention that the 25cc is a Super Tigre S2000 glow engine so it's a 1/4x32. Oh and I have one 26cc hedge trimmer motor I want to use as a test engine for my project Programmable Open Source CD Ignition PIC1840


Quote:
Originally Posted by SrTelemaster View Post
I have had better service from the cheap $12 Made in China Plugs than the expensive Rimfires.

I buy them here. http://cncengines.com/orderpage.html
Those China plugs were the ones I was thinking of using and you say you had better service with them, that's what I wanted to here. What type of ignition box are you using? Do you know if they are non-resistor type spark plugs?

Hmmm ... 5 plugs at $19.00 = $95.00
or ........... 5 plugs at $12.00 = $60.00

For 3 engines plus 2 spare plugs, I guess I could try the China ones and if I have too, I can always go to the Rimfire plugs.

Ray
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Old Nov 29, 2013, 02:30 PM
I HATE GLOW PLUGS!
SrTelemaster's Avatar
United States, NY, St Lawrence
Joined Feb 2012
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Quote:
Originally Posted by Nav_Aids View Post
I forgot to mention that the 25cc is a Super Tigre S2000 glow engine so it's a 1/4x32. Oh and I have one 26cc hedge trimmer motor I want to use as a test engine for my project Programmable Open Source CD Ignition PIC1840



Those China plugs were the ones I was thinking of using and you say you had better service with them, that's what I wanted to here. What type of ignition box are you using? Do you know if they are non-resistor type spark plugs?

Hmmm ... 5 plugs at $19.00 = $95.00
or ........... 5 plugs at $12.00 = $60.00

For 3 engines plus 2 spare plugs, I guess I could try the China ones and if I have too, I can always go to the Rimfire plugs.

Ray
I'm using C&H Ignitions Syncrospark Mk-I modules circa 1997 & CH Ignitions modules from the present.
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Old Nov 29, 2013, 02:36 PM
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United Kingdom, England, Lancs
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Is the rcxel plug ok for use on the new Saito's? I have an FG-33R3 and it has a wire clip on the plug cap to lock it in place.
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Old Nov 30, 2013, 09:31 AM
I HATE GLOW PLUGS!
SrTelemaster's Avatar
United States, NY, St Lawrence
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Quote:
Originally Posted by VinceHaworth View Post
Is the rcxel plug ok for use on the new Saito's? I have an FG-33R3 and it has a wire clip on the plug cap to lock it in place.
The FG Saitos use 10mm plugs. NGK CM-6. You can buy them for less than $5 at Advance Auto Parts.
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Old Nov 30, 2013, 09:37 AM
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USA, TX, Grapevine
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I have had good luck with the no name 1/4x32 spark plugs. I have three engines using them Ok. I lost the plug on the fourth engine and I used a Rimfire plug instead. Anyway all four engines worked Ok using the no name or RimFire plugs. No problems that have occurred using them. So I do not see any problem with using the no name plugs or RCexl plugs etc. The NGK plugs may be the best ones, but if the no name ones are working Ok, no sense swapping them out for a better plug. I'll wait for one to fail on me.

In the past the better brand plugs tended to give some more top end RPM gains over the cheaper plugs. But with the little 1/4x32 spark plugs, I haven't seen any obvious difference in RPMs that I could measure reliably. I would think that a better quality plug might have fewer missfires per minute of operation. With motorcycles or car engines cheap plugs tended to misfire around 100 times a mile. So using a better plug reduced the misfiring that was occurring thus giving one a slight gain in RPMs of around 100 or so. But with my little 9cc gas engines trying to measure a 100 to 200 RPM gain at 12000 RPMs is not going to be easily measured.
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Last edited by earlwb; Nov 30, 2013 at 09:38 AM. Reason: typo correction
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Old Nov 30, 2013, 10:32 AM
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Joined Oct 2004
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I wonder what Maynard Hill's team used for a spark plug in the O.S. FS61 that flew the Atlantic a few years ago.
Does anybody know?
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Old Nov 30, 2013, 11:14 AM
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United Kingdom, England, Lancs
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Quote:
Originally Posted by SrTelemaster View Post
The FG Saitos use 10mm plugs. NGK CM-6. You can buy them for less than $5 at Advance Auto Parts.
The NGK CM-6 looks to be too big for my Saito. It uses glow plug sized spark plug - that would be 1/4 x 32 ? right?
It maybe that the earlier Saito FG's used 10mm plug?
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Old Dec 01, 2013, 07:12 AM
I HATE GLOW PLUGS!
SrTelemaster's Avatar
United States, NY, St Lawrence
Joined Feb 2012
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Quote:
Originally Posted by VinceHaworth View Post
The NGK CM-6 looks to be too big for my Saito. It uses glow plug sized spark plug - that would be 1/4 x 32 ? right?
It maybe that the earlier Saito FG's used 10mm plug?
FG 30 & larger singles & the multi cylinder based on the 180 jug use 10mm C-M6 plugs. The FG20 & smaller singles & FG33R3 use 1/4" x 32.
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Old Dec 01, 2013, 07:35 AM
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Belgium
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The Saito SP-1 sparkplug is 1/4x32 like the glowplug and I have used these with good result.
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Old Dec 01, 2013, 08:27 AM
I HATE GLOW PLUGS!
SrTelemaster's Avatar
United States, NY, St Lawrence
Joined Feb 2012
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Quote:
Originally Posted by Reginald View Post
The Saito SP-1 sparkplug is 1/4x32 like the glowplug and I have used these with good result.
I can't see spending almost $22 when a $12 plug works just as well.

When I switched from Rimfires to the Chinese plugs I got a lower reliable idle in my FA300TTDP W/the cheaper plugs. Top end was the same.
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