RunRyder RC
 1  Topic Subscribe
WATCH
 1 page 830 views
HelicopterGasser Model RC HelicoptersOther › Spark Plug resistance
06-01-2004 10:10 AM  13 years agoPost 1
FCM

rrElite Veteran

Surrey, England

My Posts: All  Forum  Topic

Just tried running up my G230RC Benzine with a new NGK CMR7H plug installed and noticed that the Rx was going in and out of fail-safe as soon as it started.

Stopped engine and installed a used Champion RZ7C and the Rx interference has stopped.

I then checked the resistance of both the Champion and NGK plugs and these were the reading obtained:

NGK CMR7H 14 Ohms

Champion RZ7C 24 Ohms

I am running with the standard unsupressed Zenoah plug cap. I have a NGK supressed cap that has a 7 Ohm reading on its own. When you attach the NGK plug to it you get 24 Ohms.

All the measurements were taken using my very cheap and simple multi meter so the figures are not 100% accurate.

Does this mean that you should not run the NGK CMR7H without a surpressed cap? It certainly would appear to be the case.

I had intended to change to NGK plugs due to the dreadful quality of the Champion plugs that I have been getting i.e. centre electrode off-centre with the outer body hole machined off-centre as well!

I would be interested to hear from anyone who has the knowledge and experience with running these plugs in their engines.

Thanks,

Paul.

PM  EMAIL  GALLERY  Attn:RR  Quote
06-02-2004 04:49 AM  13 years agoPost 2
FCM

rrElite Veteran

Surrey, England

My Posts: All  Forum  Topic

Hello Jack, thanks for responding.

I guess the individual helicopter installation will have some bearing on the amount of RF picked up by the Rx.

I intend to carry out some proper engine-on range checks with the blades off of course, from different angles to see just how close I am to getting interference with the Champion plugs. I have never felt the need to do this until yesterday's event as the only lock-out I have previously experienced was put down to an external scource but now I am beginning to wonder if this was the case.

Paul.

PM  EMAIL  GALLERY  Attn:RR  Quote
06-02-2004 09:02 AM  13 years agoPost 3
FCM

rrElite Veteran

Surrey, England

My Posts: All  Forum  Topic

Managed to do some engine-on range checks today.

Champion plug, unsupressed cap fitted.

Set up throttle fail-safe to 'cut' and was able to listen to the engine dropping down from its set fast idle speed (clutch engaged without main or tail blades fitted) as I went in and out of range.
Tx set with antenna fully collapsed (JR X-8310 PCM-S) and facing directly at the heli.

Worst range was with heli nose/side on me at a 3/4 position which made sense to me as the engine and camera mount (machined alum.)are effectively blocking the Tx antenna. I got approx. 33-36 paces/yards range at this position.

All the other 3 positions I tried gave me approx. 49 paces/yards.

Engine off gave me at least 60 paces/yards before I could no longer see the moving tail rotor blades at all 4 positions so this may be a conservative figure.

I consider that the 49 paces is a 'good' range with the engine running but am unsure about the worst case of 33-36. Sounds a bit 'short' to me.

Comments/opinions gratefully received!

Thanks, Paul.

PM  EMAIL  GALLERY  Attn:RR  Quote
WATCH
 1 page 830 views
HelicopterGasser Model RC HelicoptersOther › Spark Plug resistance
 Print TOPIC  Make Suggestion 

 1  Topic Subscribe

Friday, December 15 - 2:18 pm - Copyright © 2000-2017 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online