Where can I find the Photos of how to replace ignition cap? I am sure Jody or A1computerfixer posted them at some point in time. I want to do the cap right....like with shrink tubing ....ect. Thanks Capt,n

The instructions I wrote with pictures is to big for a post so I sent them to your email. 

Try this site
http://www.rcaer.com/userfiles/file/...Plug%20Cap.pdf

excellent file !

Those are pictures that the lazy bum Henry stole from me [:@], why anyone would still go to his website is beyond me.

Jody, sorry for direction to pirated stuff.

Jody, I really appreciate that. That was just the data I needed. I would have replied sooner...just got home a very short time ago. Best of luck with the new job. Best Regards Capt,n

Jody, what’s the resistor for? Aren’t the spark plugs with the resistive element good enough for RF suppression? Dan.

There are no CM6 resistor plugs....
No one can convinvce me that a shielded ignition system even needs a resistor anywhere in the system..
Anyone ?

The resistor should keep interference out of your radio system. Can anyone tell me how the resistor does this? It looks like all the voltage must pass through the resistor befor reaching the plug.... but what does that do?

Thanks loads,

Ernie Misner

The metal shielding keeps the RF from the radio.
Magneto ignition systems on Quadras and Zenoah and ALL convert6ed chainsaw engines have no shielding, just solid copper center coil wires and resistor spark plugs..
Non resistor spark plugs make major RF interference on these engines, changing to a resistor plug stops it....
Must be magic or voodoo...
Sometimes a Bosch cap stops interfenence on magneto engines, it has a 1K resistor in it...
Early RC EXL igitions had no resistor in the cap, just a short piece of wire like a paper clip plugged into the plug wire to contact the spring in the top of the silicone boot inside the metal cap...Have some here....They worked very well, still do, didn't have the funny advance curve....

What about replacing the whole wire...................

Ralph,
For one, the Vlach ignitions as used before MVVS switchhed to the MSR-ICU units have a feedback from the plug to regulate the advance. Failing to use an R-type plug upsets the ignition timing big time. Been there, done that.
Don't ask me how it works, but it is very clear that it is not only RI suppression that the resistor is there for.

Could be, I only know about mine, C%H, and RC EXL... They use an electronic advance originally made by Ed Vollmer, called syn cro spark...
If it takes a resistor to make it work, I haven't seen it...Coirrect me if I,m wrong, Chief .... Or Bill....[8D]





could be,

Hey P.E.,I ran ICU with cm6 once sarted and ran,then after restart would only pop or sputter,changed back to rcexell and fine,guess it reset/calibrated somthing in ICU?

This look familiar to ya?

Spark Plug Cap Assembly Procedure
http://www.rcuniverse.com/forum/fb.asp?m=9988141
.

Now those be some OLD "end nipper" cutters there in pic number 9. They look like some of my tools that I got from my dad, am I'm 56!

AV8TOR

I have a pair that don't look that good!
How about that heat gun.......there's old.[X(]

Some more info is needed. Changed timing? did you try a fresh sparkplug? What battery? wiring Harness OK? Type of ICU (L, S, P)?

In pic #4 is there a small spring that the end of the resistor wire pushes up against inside the "teflon"?

There is...The resistor goes through it, doesn't matter if it contacts, (probably doesn't) the spark will jump the gap to the spring to the plug top anyway...
NO, the RF won't magically go through the shielding..The ignition will still work if the resistor is replaced by a solid wire...Some are anyway, I can take some old caps apart if someone is a disbeliever..

I've been told that if you look at the spark on a scope when using a resistor it lowers/delays the peak, kinda knocks down some RF, but I do agree a shielded ignition should not have an RF problem. Hell, I ran an AM radio on my first giant scale stinger with a unshielded G-62 without problems, then you lightened and converted it for me about 8 years ago, still no problems

Do you Guys remember the "Booster Gap" spark plugs that was on the market years ago? It was said that it help clear a plug from fowling. Or something like that!!!! Capt,n

The resister greatly reduces the "ringing" of the high voltage path from the coil to the plug, this ringing is what causes the R.F. generation, the resistor does effect the ignitions characteristics, mostly reducing the duration of the spark.

The old booster gap was fairly effective in reducing plug fouling in some engines that were prone to it, the availability of modern oils that produce less deposits eliminated the need for the booster gap for the most part.

The introduction of Capacitive Discharge ignitions systems with their very fast secondary voltage rise time did more than anything in reducing plug fouling in 2 stroke engines, Capacitive Discharge systems tend to produce more R.F. interference that older type of ignitions which is why more shielding is required when using them in close proximity of radio equipment.

i thought i'd bump this up.....i will be changing a cap soon, and used this thread as a reference....it took me a long time to find this, maybe someone else will find it helpful