Which Glow Plugs for K&B outboards?

[Fred37]

Hi Guys; I've looked through the post for quite awhile to find any information on which plugs to use on K&B outboards, both the 3.5 & the 7.5. I couldn't find any reference material anywhere. Is there a different plug to use with different nitro mixes? How do you know when to use a long or short thread? I've heard of people using spacers on the heads to facilitate using a long reach plug to increase the combustion chambers size. Sounds radical to me, but what do I know? Any discussion would be greatly appreciated.

 

[chunk t]

Fred,

You've asked a couple different questions...

!. different plug for different % of nitro? I've found temperature to be more of a factor than nitro %. In the general Boating forum there's a "fast facts" thread about drag racing and how many amps it takes per cylender to ignite the nitro. True stuff, that is why alcohol is added to our model fuel. It has a lower flash point (plug ignites alcohol, alcohol ignites nitro).

2. I know I'm going to get jumped on for saying this, I personally do not advocate using a long plug and adding an extra spacer. I feel it compromises the integrity of the seal between the glo-plug & head.

3. Some boaters will run a longer plug over the stock size because they feel the longer plug will hold heat better for a better ignition of the fuel

4. Plug length. I choose a plug which comes down flush with the top of the "dome"

5. Go to www.mecoa.com and "click" K&B engines/parts & exploded views/click here for new page, than find your engine and bring up the PDF.

6. What plug is best? It's a matter of personal preferance. (I'm not touching this one, I don't want to start any fights! :lol: )

chunk t

 

[shoboat]

Fred,

Try this angle on everyone. What plugs work best for your outboard and

why? Maybe we will all learn more about plugs. Me personally, I like the

cone-lock type plugs in the 6 to 8 heat range. I think they seal better,but

they are more expensive. You get what you pay for I think.

Good Luck Testing,

Mark Sholund

 

[Jerry Dunlap]

Here's what I'm running:

K&B 3.5 - K&B 1L

K&B 7.5 - K&B HD

Others are probably running McCoys.

JD

 

[Lake S.P.O.R.T.]

I have seen several posts here concerning the mc-9 plugs and why people do or do not run them. I have been running them in an SS with no problems. I have not experienced the "lean out" problem that some say they have with the SS. I was real skeptical about the engines when I first switched from the older water cooled ones but I am very pleased after running them now for over a year. It could be that those who have had heat and plug problems are running the heads extremely tight. I keep my stock engine head between .010 and .012 and have no plug problems at all.

 

[GRoth265]

I'm running MCcoy 8s in my 3.5ss and #9s in my 7.5 pro with 60% nitro.

Works for me. Greg Roth

 

[[email protected]]

I use a few differnet types of plugs. Mostly McCoy 9's & 8's, but I've found the O'Donnell plugs to work just as good in certain motors.

When my kids run the 3.5 tunnels, I put a K&B idle bar plug in. I haven't changed the plug in about 3 years. And almost performs as well as the other brands.

The oldest plug I have is about 18 years old. A guy gave it to me one time and told me they took them off the market because they never broke, he was right. It's a normal looking plug but the coil looks like they poured milky white plastic inside of it. I use that for my kids boat too sometimes, amazing plug.

 

[Fred37]

Hi Guys; I've looked through the post for quite awhile to find any information on which plugs to use on K&B outboards, both the 3.5 & the 7.5.  I couldn't find any reference material anywhere.  Is there a different plug to use with different nitro mixes?  How do you know when to use a long or short thread?  I've heard of people using spacers on the heads to facilitate using a long reach plug to increase the combustion chambers size.  Sounds radical to me, but what do I know?  Any discussion would be greatly appreciated.

94593[/snapback]

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I want to thank all that responded. It certainly gives me a lot to look into and experiment with. But so far that seems to be a major aspect of boating; Testing! Testing! Testing! What fun.

 

[Gattorno]

hey Fred,

I tell you only mind that the glow plug O.S. #8 it burns very fast, so neither use it, the one that me to given good result is the McCoy #8 and #9, very good, above all if you use great% of nitro and modify your engine, do not think more buy them.

Atte. Gatt.

 

[james irwin]

Fred,

You've asked a couple different questions...

!. different plug for different % of nitro? I've found temperature to be more of a factor than nitro %. In the general Boating forum there's a "fast facts" thread about drag racing and how many amps it takes per cylender to ignite the nitro. True stuff, that is why alcohol is added to our model fuel. It has a lower flash point (plug ignites alcohol, alcohol ignites nitro).

2. I know I'm going to get jumped on for saying this, I personally do not advocate using a long plug and adding an extra spacer. I feel it compromises the integrity of the seal between the glo-plug & head.

3. Some boaters will run a longer plug over the stock size because they feel the longer plug will hold heat better for a better ignition of the fuel

4. Plug length. I choose a plug which comes down flush with the top of the "dome"

5. Go to www.mecoa.com and "click" K&B engines/parts & exploded views/click here for new page, than find your engine and bring up the PDF.

6. What plug is best? It's a matter of personal preferance. (I'm not touching this one, I don't want to start any fights! :lol: )

chunk t

HEY CHUNK WHY NOT START SOMTHING ??? HELL I DO ALL THE TIME , HEHE GOD BLESS

 

[james irwin]

Fred,

Try this angle on everyone. What plugs work best for your outboard and

why? Maybe we will all learn more about plugs. Me personally, I like the

cone-lock type plugs in the 6 to 8 heat range. I think they seal better,but

they are more expensive. You get what you pay for I think.

Good Luck Testing,

Mark Sholund

[ THERE IS A LITTLE TRIC YOU DO TO A STD PLUG TO MAKE IT OUT RUN ( RPM ) ANY STD PLUG OUT THERE FOR A STD . I REALLY LIKE THE HP K&B

 

[james irwin]

I use a few differnet types of plugs.  Mostly McCoy 9's & 8's, but I've found the O'Donnell plugs to work just as good in certain motors.
When my kids run the 3.5 tunnels, I put a K&B idle bar plug in.  I haven't changed the plug in about 3 years.  And almost performs as well as the other brands.

The oldest plug I have is about 18 years old.  A guy gave it to me one time and told me they took them off the market because they never broke, he was right.  It's a normal looking plug but the coil looks like they poured milky white plastic inside of it.  I use that for my kids boat too sometimes, amazing plug.

94796[/snapback]

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HEY RC/ YOUR ARE TALKING ABOUT OLD PLUGS ? DO HAVE ANY CHAMPION GLOW PLUGS . NEXT TIME YOU SEE ME , LOOK ON MY HAT ,..

I PUCHSED THIS ONE IN 1951 AT DETROIT NATS (OK , OK IAM THAT YOUNG , ALL WE HAD THEN WAS TETHER BOAT RACING , 60S WERE RUNNING IN THE HIGH 90 S . 45 S WERE IN THE HIGH 60S , O YEH THAT WHITE STUFF YOU ARE SEEING IN THE END OF THE PLUG? THATS A VERY HARD GLASS , MADE IN INDPLS IN. BY FRED BALDWIN AND GLOE BEE ) GLOE BE ALSO HAD A VERY GOOD PLG IN THERE COIL PLUG , IT LOOKED LIKE THEY HAD A STOVE ELEMENT IN IT , THEN THEY PORED IN THE GLASS . DONT ASK ?? I DONT KNOW HOW THEY GOT THEM TO WORK WTH THE GLAS COVERING THE ELEMENT ? I WAS NOT ONE TO COMPLAIN , I GOT THEM FOR FREE.

 

[[email protected]]

Jim,

that's cool And your right, it is a Gloe Bee plug.