Hi Guys,

I have a friend with the Evolution 58 engine and he looking for a new spark plug? The spark plug number that is listed on the Horizon web site is for a plug that is too small for the head. Any help would be greatly appreciated.

Good Luck and God flying..
David

There are two types of plug, depending on the ignition in use.
Vlach ignitions need Brisk UR17 tapered seat garden appliance spark plugs
ICU ignitions need the smaller CM6 (M10) plugs.
MVVS dealers worldwide carry them.

Does MVVS suggest use of the comparable NGK plug?
they are (after cutting down cap) a little taller than the Brisk -
ZDZ went thru all of this at one time and the cap was not exactly right on some setups.
They now use the NGK exclusively

pe, reivers

My friends ignition system requires the larger plug. I am not familiar with the Brisk plug you are making reference to. Do you know if NGK or another manufacturer makes the larger plug for the engine, and if so, the model number? Your assistance is greatly appreciated..

David

MVVS does not suggest other than the Brisk UR17, to which the caps are adapted. This is a standard tapered seat garden appliance plug, and in MVVS engines they are excellent.
Champion DJ7Y (long nose) and DJ6J (cold) have similar dimensions, but I have not had opportunity to check out the R-types,
Bosch HS8E (hot) or HS5E (cold) may also fit.
NGK BM5F, 6F and 7F (hot>>>cold) may be candidates if the internal spring can compensate for dimensional differences.
MVVS still supplies the UR17 plugs, so Horizon will be able to supply them. I do as well.

But they are non resistor plugs are they not?

OK kiddies ---
I jest measured my Brisk and my BM6F and BPMR6F NGK plugs--from seat to top of plug and all plugs are cut off to aprox 1 mm thk on electrode.
there is 3 mm MORE height on NGK -than Brisk
On the ZDZ's the spring in the cap usually allowed this variation -on earlier caps - on later caps when engines came with the NGK-- the Brisk plug barely touched the spring in the top- not good -
So
as long as th plug will allow the cap to compress but not crunch the spring - the various plus all work
in fact -- my ZDZs don't seem to care if I use resistor or non resistor plugs - extended tip or non extended tip and I have never -ever had a hint of ignition interferrence
The Evolution setup is basically the same - EXCEPT the spring take up could be different - so if you make the change pay attention to the above note
If you buy a plug from yer local supplier of spark plugs - just carefull y cut of the top of the electrode to same thickness as your Brisk plug. as for gap - .025 is all you want - you can go a little less
makes no appreciable difference. Don't go more gap tho!

Just add an "R" to the code, and it will be a resistor type.
I ran the non-resistor Champion types because of availability, and neither engine, radio gear or ignition seemed to care. I will not advise to use nonresistor types though. My nonproblematic running may have been an isolated case.