Smallest CM-6 spark plug boot
 

Hey guy's

I have a tight installation and am looking for the shortest (height wise) boot I cn use with a CM-6 plug. The engine is a XZY 53ccSTS twin and so the ignition is brand X??

Thanks

dave

RE: Smallest CM-6 spark plug boot
 

Call Valley View RC and talk to them about the billet spark plug caps.

RE: Smallest CM-6 spark plug boot
 

Remember that the CM-6 is NOT a resistor plug and you must use a shielded cap.
Don't let your esthetic wants, cause you to have a one flight plane[:o]

RE: Smallest CM-6 spark plug boot
 

Ahh, but the billet cap used on the great CH ignitions handled that problem well. It had all the right goodies to permit functionality. Never once have I had an interference issue with the billet caps and shielding on my engines.

RE: Smallest CM-6 spark plug boot
 

T.O.M. the cap is great, but Ive seen folks not use because they wouldn't fit the cowl and they did not want to destroy the planes good looks by cutting holes in the cowl.
SO they flew them with rubber boots..... thus my comment

RE: Smallest CM-6 spark plug boot
 

Good point. There comes a point where adhering to scale cosmetics can cost a person the plane. I have a 40% Giles with a hole cut in one side of the cowl for the plug cap. It took a little to get me to do it but I knew then the plane would never crash because of a cut plug wire or shorted plug. Three years later she's still good to go.

RE: Smallest CM-6 spark plug boot
 

There's some new chainsaws just out from Husqvarna and the have strato charged engines and also NGK CMR6H spark plugs as well as computerized mixture control on the Zama carbs. These are some of the first big saws I've seen that didn't have NGK BPMR7A plugs. 555 and 562

Notice the resistor type CM6 plugs!

RE: Smallest CM-6 spark plug boot
 

Thanks mate,

Being in the land of Oz, I've just emailed jody to see if he has anything that will help out my situation. I'll Keep you guys posted on what the outcome is.

Thanks

dave

RE: Smallest CM-6 spark plug boot
 

The CM6 and CMR6H are not even close except for the 10mm threads. The CMR6H has a longer reach and longer porcelain. Not what you want if you are having cowl clearance problems.

RE: Smallest CM-6 spark plug boot
 

:D
Get over it, the smallest spark plug that will work for any length of time is the Rimfire and its clones...1/4-32 thread...
There are much smaller plugs but finding a cap will be well nigh impossible...As well as a way to put it in your engine....
Marvin and Morrison website has the plugs...Good luck...;)
Look on the conversion forum , find Gas/glow, use glow plugs...No caps at all :D

RE: Smallest CM-6 spark plug boot
 

Thems' are small plugs!!!

No responce from jody yet. I might send the email to sale as well.

Thanks

dave

RE: Smallest CM-6 spark plug boot
 

Jody and family are on vacation at the moment.

RE: Smallest CM-6 spark plug boot
 

I bet that twin would really run nice on a mix of gas/glow fuel. I have a video of a MB290 enginethat was covered with ice. I put a video on Youtube of it starting and running with a sheet of ice on the engine. Yup...I like to experiment...but I find out what does what indoing so! Capt,n
http://www.youtube.com/watch?v=c85M0Rq1TKE

RE: Smallest CM-6 spark plug boot
 

Ah, that will explain why no response!

Back to glow???? now that would be like going backwards[X(]

Has anyone got any experience with the rubber boots they normally use on lawnmowers, wipersnippers etc? will they work with a separate earth lead from the shielding?

Thanks

dave

RE: Smallest CM-6 spark plug boot
 

The CH ignition systems that used a rubber boot that had the wire braid from the spark plug wire gathered up and gounded at the plug base used a resistor type spark plug

RE: Smallest CM-6 spark plug boot
 

Here's a pic of my homemade twin 50cc Echo setup to run on what we call Gas/Glow. Runs great! I've been flying it for years this way. The glow plug wires are for starting only; no glow heat is necessary after the engine is running.

Gas/Glow info: http://www.rcuniverse.com/forum/m_80...tm.htm#8009384

AV8TOR

RE: Smallest CM-6 spark plug boot
 

Yes, but what is the difference from an RFI perspective? A resistor type spark plug requires a resistor inline with the high tension lead before the plug, the other type does not. but does this have any effect on the interference that may be emitted?

If it does, can you cover the rubber boot with a wire braid to have the same shielding effect?

Thanks

dave

RE: Smallest CM-6 spark plug boot
 

RE: Smallest CM-6 spark plug boot
 

You may never know unless you try it?

RE: Smallest CM-6 spark plug boot
 

Trying to just shield the wire with braid will not by itself eliminate the RFI from a non resistor plug such as the CM-6. The braid connects to the ignition case and is not a ground by itself that way. The billet caps also have a resistor in the plug wire.

RE: Smallest CM-6 spark plug boot
 

Back in the day the old A&M clone of the C&H ignition used braid large enough to cover the rubber boot and the hex on the spark plug..Held on with a small hose clamp...It worked...They even took a C&H box apart and flattened it to use for a pattern for their box..They were so smart(?) they used a part or two in the circuit that did nothing....[&:]

RE: Smallest CM-6 spark plug boot
 

Ralph,

Simply wrapping a plug wire with braided shielding to compensate for a non resistor plug, similar to the shielding on the current RC Exl products, will leave the user pretty unhappy. We both know that. The old CH ignitions using the braided strap were done quite differently that what is seen today. You still have the pervasive issue of people failing to connect the other end to a real ground instead of an engine mount screw. Even then, the vast majority of those were used on resistor plugs.

I certainly don't want to be the one to get some guys hopes up by telling him he could just wrap the plug wire and can with braided cables and send him on his soon to be less than merry way using a non resistor plug. Your point about covering and securing a braided cover does indeed work when done correctly, but what are the odds the neophyte will do it correctly?

RE: Smallest CM-6 spark plug boot
 

Not good....So How come all my conversions are out there running with no shield at all ?
In 1972 we flew on AM with no shielding and a resistor plug with a rubber boot...G23, G38, G45, and G62....And Quadra 35s and 40s.. And more..
All the Zenoah conversions use the stock Zenoah coil, mounted on the outside of the case, with the circuit inside the mount...No resistor anywhere in the circuit or plug wire, just a resistor plug....The spark plug wire is solid copper in the center...
We fly STOCK GT80s on our 140 mph race planes, 4 in the air at a time, 1600 feet from the planes...NO interference with the old FM radios, and now no interference with the mandatory 2.4.....

RE: Smallest CM-6 spark plug boot
 

You make the guarantee to the guy Ralph. Let him know you'll be there for him with dollars if he fails to make things up right. I'll not argue with you here, but instead let you walk the guy through the process and therefore accept responsibility. Lots of things were done differently in the old days, but if you didn't shield a non resistor plug correctly I don't care if you flew it on AM/FM mulitplexed the thing would go down. You can't do it today with 2.4 either if the shielding isn't right if there's no resistor in line with it. We both know the resistor plugs don't need n additional resisitor, but that's not what the guy is talking about here.

RE: Smallest CM-6 spark plug boot
 

I think a sparkplug wire with the resistance built in will work or if you use the correct rersistor sparkplug, that should work. No guarantee from me though. I know I flew a airplane with a Zenoah mag ignition on the old 72 band and it just had a rubber cap.

Capt,n