Quality and life span of spark plugs

[Mark P]

I searched the archive and found some posts about plugs and heat ranges. Thought I'd ask Poggers about which brands they felt were better quality and life span. How many hours(miles on a road/DS bike) do you run them before you simply replace them? Thanks.

[Kip Kern]

W3AC or W3AS Bosch.  Run em until they drop, excellent and available at Rock Auto by the case.  Fits every vintage Penton or KTM engine, .022 Gap. Dare you to find better![}:)]

[OUCWBOY]

I just ordered mine from an old VW repair shop. I have always used Bosch plugs in every bike I've owned since my New 1969 Six Day had one in it when I bought it and thought it lasted so much longer than any other brand I had been using. I switched everything over back in the day, and never looked back.

Donny Smith
Paragould, AR

[Bob Bean]

NGK Plugs.
How often?
Once a year maybe. Just because.

If jetted properly, plugs will go longer
than most people think.
Warm the bike up gradually,
Dont rev it to the moon untill the gas
has a chance to vaporize..

Bob Bean

1986 ISDE Italy
1987 ISDE Poland
1989 ISDE Germany

1970 125 Six Day
1973 100 Berkshire
1973 Jackpiner 175
1974 Penton 250 Harescrambler
1976 Husky 250CR
1985 Husky 400WRX
1985 Husky 400WR

[brian kirby]

NGK, Depends on the bike how long they last. In my 400 a plug will go for months if only ridden at MX tracks, but will die by the lunch break at an ISDT event and its jetted perfectly, maybe even a tad lean. I dont even know how long the plug has been in my 100, maybe two years? I think its only the second one I put in it, and even then I only did it because I was nervous not because it fouled.

Brian

[wfopete]

With 30+ year old motors, igntions/wiring, worn Bings, seals and a never ending combo of jetting, pre-mix ratios, fuel & oil brands it's tuff to point a finger at a plug.  For most folks with plug fouling issues, I suspect a good carburetor & careful attention to jetting will do more for plug life than anything else.

Pete Petrick
175 Jackpiner
Slow but Good

[TedG]

I worked at a Penton dealership for years and have owned Pentons. I have tried all sorts of plugs, NGK, Nippon Denso, Bosch, etc. And with the worst seemed to be the NGKs, second worse the Nippon Denso, but the Bosch seem to go on and on and on. And if they finally do stop working, you can clean them and and away you go again.
I have had great luck with NGKs and Nippons on any other bike.

[Lloyd Boland]

I have used NGKs for years in the MC5 and other vintage bikes (CZs, etc.).  I have found if the bike is fouling plugs, it is usually a carb problem and not the plug.  I replace the plug before every race in all bikes (not every moto).  I usually start the bike on the old plug, it usually starts up fine without any evidence of a problem, warm the bike up, and then shut it down and put in a new plug for the day. Kick it over and it starts right up.  Listen, after all the money spent for the day, bike prep, fuel for traveling, bike fuel and pre-mix, entry fees, etc, etc, etc, who wants their day ruined by a fouled plug.  

On the other hand, my 2008 450F (desert play bike) is on the same NGK for almost 3 years. Probably should change it soon, but it takes a lot more work to change a modern bike 4-stroke plug than the old vintage bikes.

Lloyd

[OUCWBOY]

I just will say this. I would NOT use a NGK if I has a lifetime supply!

Donny Smith
Paragould, AR

[tomale]

Wow Donny, that is amazing. I have used NGK's for years with out any trouble, I can remember just a few times I ever had a plug go bad, and I use mine for months before I even think of changing it.. I will probably change them out here soon because the weather is getting cooler and I will have to make a few jetting changes..It may not be the best plug but it is available almost anywhere and holds up fine, even on all of my old bikes...

Thom Green,Still crazy after all these years!
76' 250 MC5 (orginal owner)
74'250 hare scrambler (project)
74' 1/2 440 maico
78' 440 maico
72' cr125 Husky (project)
93' RMx 250 suzuki