Any one know for sure if M4F spark plugs are the same as CM-6 plugs?

Also what is a good quality replacement for these and where to get them? such as NGKs

Not looking to change plug caps and wires

If your having trouble with the steep price of CM6 plugs ...
These are genuine NGK CM6 plugs from boats.net

http://www.boats.net/parts/detail/ho...052-56471.html

I got a box of 10 for around $25- shipped

Not worried about price, just if they are the same thing and where to get them.

Thanks

I get the CM-6 plugs at the auto parts store up the street

These are equivalent to NGK CM6 spark plug:

NGK STK: 5812
AC Delco: M8 (Non-compact size, but similar thread and thermal rating)
Champion P/N: UY6
Champion STK: 842
Denso P/N: U20M-U
Denso STK: 6003
GM OEM NR: 1559459
Motorcraft P/N: BT8
Napa: X581
Prestolite: 09-10-06

http://www.sparkplug-crossreference.com/index.php

NGK numbering system:

http://www.ngk.com/sparkplug411_manu...nufacturerID=1

The C indicates the M10 thread and 5/8" hex size.
The M indicates a compact size.
The #6 indicates a medium heat rating (2 is hottest and 12 is coolest).

The best substitute for a NGK CM-6 (5812) is another NGK CM-6

100% agree.

Some of the plugs you listed are not the same. They have the same thread but are two to three times the size of a CM-6. The The Denso U20M is the exact same fit as the CM-6. For example below is a picture of a Delco M8, it is about three times the size of a CM-6.

There are only 2 other plugs made that interchange with the NGK CM-6 and still fit the same sparkplug cap, Champion Y-82 and Denso U20MU, the best of the 3 by far is the NGK.

Have no idea what an M4F is, it doesn't come up in any of my searches.

The M4F comes with the RCGF 15cc engine (China).

http://www.himodel.com/engines/Glow_...ngine_M4F.html

I have seen reviews showing some owner's complaints about the bottom isolator breaking and damaging engines.

That is the problem with plugs made in China. Very poor quality...

Sounds like the DL OEM plugs.</p>

M4F might be an apt identifyer of a plug developed over several minutes of research. The "M" could represent "minutes", the "4" could relate to the number of minutes it could be expected to last, and the "F" could represent the first letter of the exclamation when the plug fails.

LMAO Pat......your mind ceases to amaze me.

Post #5 has been corrected.
Thanks, Super08.

Lnewqban - "Do not go around saying the world owes you a living. The world owes you nothing. It was here first." Mark Twain

Read more: http://www.rcuniverse.com/forum/m_98...#ixzz0rgeVzs00


I like you already. Much truth in your signature line[sm=thumbs_up.gif]

Thanks TOM, but it's not mine.
The good old Mark Twain wrote it long ago.

From him, I also like these ones:

"Always do right. This will gratify some people and astonish the rest."

"A lie can travel halfway around the world while the truth is putting on its shoes."

He died 100 years ago, but the world and we people are about the same still today.

NAPA Auto sells CM-6 plugs, genuine NGK for $6.99 all day long. Forget the Chinese junk, if NGK is'nt on the plug, then its a fishing weight.

Your local Honda generator dealer will have the genuine NGK CM-6. The Honda part number is 98052-56471. I bought a few a couple weeks ago at
a Honda generator dealer for $2.59 each.

I can only speak for the NGK CM-6 and the Denso U20M-U, both are a good long lasting plug, as far as performance and life span, I can tell no difference between them.

The Chinese M4F spark plug is inferior quality, I have seen the plating on the metal part of the plug that is down in the cylinder come off and damage the piston, ring, and cylinder wall.

I bought 20 from the boats.net online shop. The supply can last for a long long time.

Hence the problem.

Ordered some NGKs from boats.net.

Thanks to all for the input and info.

Genuine NGK CM-6 for me.

HI,
can anyone recommend a place to buy the Denso U20M-U spark plug. I need some spares. I find in my installation the Denso runs my DL 50 better that the CM-6.

thanks - ken kalynuk

Antique should have the Denso U20 spark plug! Good man on engines too! Capt,n

clubplug,net $5.75