Is there any reason to use other than harley plugs?
Do any last longer,fire better ,in you guys experience?
thanks
Ben in Texas
xl1200c '03

no, use what evers cheap, plugs just light the fire

the whole system must work together and any sparky will work for a stocker

I use the Champions because they are easy to get and don't cost much. I don't often buy Harley products because I know from experience that they just get the cheapset supplier to make there stuff and sell it at a ridiculaous price just because their name is on it! The only thing I found to be of reasonably good quality from them is their Chrome but I know some who would disagree with me.

Take a tip....Don't buy their oil, their plugs or their filters. Save yourself some money.

Just get what works for you. The HD are nothing special and I don't think you'll find anybody who can argue that any other spark plug makes a big difference.

This is a very good question and one that is just as complex. Yes, their is a very big difference in plugs and an even bigger difference in lubricants. First, the plugs. If you put two different plugs in your engine and hook it up to a scope you may find that although the heat range, according to manufacturer, may be the same, the KVA reading is different from one plug to the other. Therefore, you want the one with the greater KVA reading, which is generally the factory plug as opposed to the aftermarket. Second, is the oil. Oils in V-twin, air cooled engines are critical in that they must tolerate a wide range of plus and minus swings in temperature. Therefore, you want an oil that (A) has an extremely high flash point (synthetics are quite often above 400 degrees) and an advanced additive package. I use the Syn3 because my sporty runs very cool even in traffic and the temps are well below 200 most of the time. Dino oil couldn't begin to come close. I have heard of folks running standard 15W50 Mobil 1 automotive oil, which has a flash point of 415 degrees according to the NOACK volatility tests. I haven't tried this yet but tests completed by a professor at UCLA indicate excellent results and the oil is a mere $5.00 per quart as opposed to $9.00 a quart. So, for those that say stay cheap, I offer you this, when you have owned your bike or car for many years and it seems tired, mine, having been driven or saddled for just as long, will seem almost new because the wear factor is 1/10th that of the cheap oils you save a few bucks on....................

Stephen Hawk

Virtually ALL spark plugs are over rated. So too the advertising hype that accompany them. As long as it fires, it's a good plug. NEVER buy HD plugs. Too expensive.

I've tried a wide variety of plugs ; Harley platinum, plain, gold, screaming eagle, plus Splitfires, NGK's, ETC. The one's I like best are the Autolite Platinums (MP4164). Got 3400 mi on the current set and they still pull like a FR8 Train.

Like everything else, the name adds to the price. :tour

Having a later model bike gives you some options. I have an old ironhead and the plug reach is shorter. Also, mine tends to indicate a rich condition when I ride it in city traffic for very long. Mind you, that's when it's tuned to run it's best. Most every plug I've tried will carbon foul in 2 or 3 days of city riding unless I'm riding the hell out of it, then I'll get maybe a week. I haven't found a platinum plug for it yet but splitfire makes one to fit, and it hasn't fouled yet. The heat range seems to be the same. Any attempt to adjust the carb so the bike runs leaner just makes it run like crap. Flat spots, hesitation and all the other typical "too lean" symptoms. I guess it just likes to "have it's head" and run fast! (stock '77 keihin carb)

I run Mobil 1 synthetic with a revtech filter for oil. use the 20w50 harley or Amzoil in the tranny and champion plugs. The only reason I'm paying for the harley oil for the tranny is because it isn't always convenient to get the amzoil.
Works for me!

Working for Mobil I say always use Synthetic you mean people! (I use SE Syn-3 which is the same thing!)

As for spark plugs I use the SE EX12P (32321-91) and they seem to work ok.

As with all things you pays yer money...... But as with ALL manufacturers H-D are, of course, going to charge more for something with their name on it. I have been buying enough Jap stuff over the years to say they are just the same. The only difference with Harley is the wider choice of bits/suppliers available. This is a good thing as it gives people a lot of choice.

dabronco..I believe your CV is the older 38 mm type. The "SPORTSTER PERFORMANCE HANDBOOK" by Buzz Buzzelli recommends replacing it with the current 40mm type. Buzz says there tons of them laying around Indie shops from guys who went to an S&S carb. They are easier to dial in and have an accelerator pump.

It's not a c/v carb. It's a keihin butterfly carb, and it has an accelerator pump. The pump's stroke might be too long, explaining the apparent rich condition in town. (squirts four times goin thru the gears each time compared to running steady on the HWY.)