NGK Spark Plugs, BR9ES vs BR9ECS and BR9ECS-5

Ok, I'm confused. According to my owner's manual for my '04 SX Viper ER 700, the plugs I use are BR9ES gapped to .028-0.31".

I went to buy new plugs so I thought I'd check to see what was in the engine from the last tune up by my mechanic, just to double check. While I couldn't easily see what was directly in the head, I checked the 3 spares on the side, they were BR9ECS-5. I went to the dealer, showed him what I had as spares, and he gave me BR9ECS (no 5 suffix). What the heck...3 different plugs. So I searched and found this PDF by NGK explaining the differences...

http://www.google.com/url?sa=t&rct=...ieXuWImPXfFSq0pEv8WcxHA&bvm=bv.81828268,d.cWc

Basically, the ECS plugs seem to be an optional replacement for the ES plugs, given more clearance, but they are not recommended to be gapped given how the ground electrode is designed. Ok, makes sense I guess, and the ECS plugs seems safer for the engine, so I would imagine they are fine for he 700 triple. But the gap is what's getting me.

The PDF linked above says the plus with the 5 suffix is pregapped to .020. I read some other posts saying for some other brands the -5 designation is good for carbed sleds. But that's way below my desired range of .028-.031. Why the heck are they in my spare slots...I can't answer that, but I assume I would NOT want to use them, as the sled would run like crap with such a tight gap. I'll have to check what's in the engine when I slide the sled out of the trailer this weekend.

But the question is the regular BR9ECS plug the dealer gave me. According to the PDF, they are gapped around .032. I have to check them to see what they really are set to, but if they are .032 Is that ok to use as is, given the Yammie spec of an upper gap width of .031? Is 1/1000th really going to matter? Should I run the BR9EC6 (no 5 suffix) and stop over thinking this? Or is there a reason I can't determine that in this sled I should stick with the regular BR9ES? And will I really do anything to the plug if I tweak the gap?

Thanks

Way Over thinking this. Just run BR9es and gap to spec. No reason to run anything else.

Br9es, a lot cheaper too

^^^^^x3.

LOL. Yeah, I do that sometimes. Dealer didn't even have regular BR9ES, only BR9ECS, and I'm not opposed to a few more bucks for better clearances. But that's why I was asking about the gap differences, or if you can tweak them...But I assume I should not be running the BR9ECS-5 given the .020" gap...

Run the br9es or br9eya. EYA plugs have a v groove in them, and are designed to be more resistant to fouling. I have run them in my sxr 700 for years, and put them in every sled I replace plugs on, requiring ES plugs

dwarf717 said:

Run the br9es or br9eya. EYA plugs have a v groove in them, and are designed to be more resistant to fouling. I have run them in my sxr 700 for years, and put them in every sled I replace plugs on, requiring ES plugs

Click to expand...

I just pulled what was in the actual motor. BR9ECS. Given that I have had 0 problems, I'll stay with those. $6 a plug, but that's ok. I'll junk the BR9ECS-5s in the spare plug holders.

I just checked the gaps on the BR9ECSs I got from the dealer, and they look, and within the recommended range from Yamaha. Right at .029" with a feeler gauge. Perfect.

The ECS is the correct plug. It the safest plug least likely to detonate by design. NGK makes the ECS for other engines. Ski Doo uses stock# 6669 BR9ECS at .020 Yamaha uses stock#4677 BR9ECS at .031
---Mac---

The ES is factory equipment, ECS is factory equipment for the SRX, the -5 designation is pre-gapped for Ski-doo. My 04 Viper S came with BR9EIX (iridium version of BR9ES) which I have had no problem with the little bit I have run it. NOTE: The EIX plugs ARE NOT PRE-GAPPED.

Mac said:

The ECS is the correct plug. It the safest plug least likely to detonate by design. NGK makes the ECS for other engines. Ski Doo uses stock# 6669 BR9ECS at .020 Yamaha uses stock#4677 BR9ECS at .031
---Mac---

Click to expand...

Thanks. I'll use the ECS. Funny though, I'm finding the gaps closer to .029. Just picked up 3 more for spares, same thing...

I assume too, the change in plug doesn't change the required gap, and I still want the .030 target gap...

Devilin AblueDress! said:

The ES is factory equipment, ECS is factory equipment for the SRX, the -5 designation is pre-gapped for Ski-doo. My 04 Viper S came with BR9EIX (iridium version of BR9ES) which I have had no problem with the little bit I have run it. NOTE: The EIX plugs ARE NOT PRE-GAPPED.

Click to expand...

I find this interesting, that they wouldn't just use the ECS on the Viper S at the time, I mean, why a different plug, if the ECS can be used everywhere an ES can, and it's better...

steveg_nh said:

I find this interesting, that they wouldn't just use the ECS on the Viper S at the time, I mean, why a different plug, if the ECS can be used everywhere an ES can, and it's better...

Click to expand...

http://www.portyamaha.com/fiche_sec...Snowmobiles&make=Yamaha&year=2004&fveh=176296

Link to PortYamaha parts fische for your sled. No idea why the put in and recommend the ES. Could be the $2+ difference per plug, times 3 per sled times how many sleds rolled off the line.

steveg_nh said:

I just pulled what was in the actual motor. BR9ECS. Given that I have had 0 problems, I'll stay with those. $6 a plug, but that's ok. I'll junk the BR9ECS-5s in the spare plug holders.

I just checked the gaps on the BR9ECSs I got from the dealer, and they look, and within the recommended range from Yamaha. Right at .029" with a feeler gauge. Perfect.

Click to expand...

DON"T junk the ECS-5s,the only difference is the gap and they can be gapped to whatever you want.I run my ECS-5s at 18 thou in my SRXs and yes I gap them to that spec.

What I read everywhere is do NOT regap an ESC plug as the bend is right on the weld, weakening the electrode, possibly causing it to break off. Not worth risking my motor for $18 in plugs. You can have them if you want them.

Times two. Do not try to re-gap the .018 plugs.

I should've reworded my earlier post,I re gapped my older ECS's to 18 thou not the ECS-5's.I only use the 5's now in my sleds and the older regapped ones are only for an emergency if I run out of them.I bought a box of 10 a couple of years ago so I would have enough to outfit both my sleds.

Doesn't the smaller gap cause the sled to run different?

No it will not run different. I gap my plugs at .018. I think .028-.030 is to much. It takes less energy to jump the smaller gap. A high compression motor will not run wot with a big gap. Skidoo has run .018 for years, same two stoke motor. Maybe Yamaha thinks there ignition is far superior. lol

Hmm. Makes me nervous though if Yamaha doesn't call for it.

Its extremely difficult for everyone to agree regarding any subject on this forum so here goes. Recommending .018 is just plain wrong. Yamaha designed the engine with CDI, Stator, coil and plug to operate with .028 -.030
Sorry guys. Im feeling grumpy.

Yes is takes less energy to jump.....
Yes its true much higher compression wont like......
Ski Doo two stroke engine principals the same.....
Ski Doo ignition system different. You can bet on it.
Will the engine run different. yes.
---Mac---