I used 91 and 87, and never noticed a difference at all. Actually seemed to run better and faster with 87, but that could have been the break in. Up here, 89 is only a penny more, so maybe i will use that being it is 11.1 compression.

 

More octane = less power and less mpg. If your engine doesn't knock and it's not required, don't use plus or premium. I need 93 in my scooter and 87 in EVERYTHING else.

 

<div class="FTQUOTE"><begin quote>Originally posted by: HIGHOCTANE

Thanks,yeah I tried many crossreference sites and even looked on Champions site and it isn't listed and the part number doesn't sem to jive with there normal breakdown. When I get a chance I should be able to pull one and match up something from NGK hopefully. I know Old Polaris Tech talked to NGK and they didn't have anything in copper that matched perfectly,hopefully one of the iridium plugs will match or the copper will be close enough. You just have to be careful and know what you are doing if you don't run a plug the exact demensions as stock. With 11:1 compression there probably isn't alot of room for error on how far the plug projects into the cylinder.</end quote></div>


That stinks. I really don't like Champ plugs. I won't even use them in my lawnmower. Very inconsistent results. I only use NKG or Denso Iridium plugs when I can. As a matter of fact, when the BKR6E NGK plug in my 500 needs changing (or sooner), it will get the BKR6EIX Iridium plug.

 

I highly suggest staying away from Denso Iridium plugs...I have seen the ceramic around the electrode crack(ie ceramic particles inside the cylinder,guess what's harder ceramic or the aluminum piston?) Not just once or twice have I known people who have had that happen with Densos.
NGK is the only Iridium plug I will run in anything.

 

Iridium comes from meteorites and asteroids like the one that wiped out the dinosaurs. It's rarer than silver, gold, and platinum. Even though it's just a tiny amount used in sparkplugs they must be expensive. How does the price compare to other plugs?

 

<div class="FTQUOTE"><begin quote>Originally posted by: HIGHOCTANE

I highly suggest staying away from Denso Iridium plugs...I have seen the ceramic around the electrode crack(ie ceramic particles inside the cylinder,guess what's harder ceramic or the aluminum piston?) Not just once or twice have I known people who have had that happen with Densos.

NGK is the only Iridium plug I will run in anything.</end quote></div>

HIGHOCTANE,

I will heed your advice on the Denso's. I ran than once in my previous vehicle (F150), and didn't notice any problems. However, I never had the engine apart to see any possible issues. If you have seen problems with the those plugs... that's good enough for me. Besides, I've had excellent performance out of the NGK Iridiums.

 

<div class="FTQUOTE"><begin quote>Originally posted by: jumbofrank

Iridium comes from meteorites and asteroids like the one that wiped out the dinosaurs. It's rarer than silver, gold, and platinum. Even though it's just a tiny amount used in sparkplugs they must be expensive. How does the price compare to other plugs?</end quote></div>

Yes they are Frank... I think the price for the regular NGK for my Sportsman is around $3. The Iridium is between $15 - $20. However, I like the longevity of the plugs, how smooth engines run, and how well a vehicle starts with the Ir's. Is there any performance gain... who knows? Probably won't notice much in a singe piston, 40HP engine.

Of course, I don't have one in the Sportsman yet, so we'll have to see how they perform in that application.

 

Thanks for the info, Dave. I never tried iridium plugs in anything and haven't priced them. I use platinum plugs in cars but regular plugs in most other things. Ir is about the toughest most corrosion resistant thing in the whole universe and high temps don't phase it. I see it has a lot of benefits, like lasting for years.

Frank

 

<div class="FTQUOTE"><begin quote>Originally posted by: jumbofrank

Thanks for the info, Dave. I never tried iridium plugs in anything and haven't priced them. I use platinum plugs in cars but regular plugs in most other things. Ir is about the toughest most corrosion resistant thing in the whole universe and high temps don't phase it. I see it has a lot of benefits, like lasting for years.

Frank</end quote></div>

No problem Frank. I think in most vehicle applications, the Platinum plugs are all one needs. The ECM's on most vehicles really do a nice job of extending plug life, and the Platinum plugs will go a long time. In my 5.4L F150, I was trying to squeeze every once of HP out of it I could get (towing a big boat). I put a Superchip in it, Borla exhaust, K & N filter charger, electric fans, larger throttle body, and a few other goodies... it would really run! [img]i/expressions/face-icon-small-smile.gif[/img]

 

Not only does the Iridium last a long time, it will do so under very harsh conditions. All while provide a nice clean strong spark. They are optimimum for high compression and power adder engines due to their durability.
I got hooked on the NGK Iridiums when I got into modding Mustangs. The later model modular motors would idle a little rough and the Iridiums would would make it idle noticable smoother and overall it would run better.
The 850 already idles nice,will be intresting to see if Iridiums make any difference there. I mainly would run them for the durability. They will maintain electrode shape and gap long after copper has worn away.
The NGKs I usually pay $6-8,depeds on which plug. The Densos(that you couln't pay me to use) are about $15+