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BR8ES Alternative? Buy At Wal-Mart??

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Here is the cross reference for that plug.

NGK STK: 5422
Accel: 142
AC Delco: R42XL
Autolite: 3704
Beck Arnley: 176-5123
Bosch P/N: W4CC
Bosch STK: 7530
Champion P/N: RN3C
Champion STK: 880
Denso P/N: W24ESR-U
Denso STK: 4033
GM OEM NR: 5613388
Mopar: 82300312
Motorcraft P/N: AGS1C
Motorcraft STK: 63
Splitfire: SM040D
NGK TYPE: MARINE
Thread size: 14MM
Hex size: 0,81
Reach: 0,75
Seat type: GASKET
Projected tip: NO
 
Nice list, and plug info :hurray:


Just to throw in my 2 cents... over the years, I have found that NGK stand up to 2-stroke engines better than any other. I recommend using them.
 
Besides...ngk are cheap! I buy mine by the case and swap in new ones almost every trip out before we launch. That goes for boat and ski.
 
yup NGK all the time best plug you can run.... do you all run them with the regular gap? i think its .030 or something like that?
 
i was getting a lil bit of build up on mine, thinking about opening them up to about
.038 think it would be ok?
 
i used to test the gap when I pulled them out of the box. Every one has been right at .027 or .028. So I don't even check them anymore. Just pop em in.

I just quickly look at them to make sure they are way over or under, visibly so.

EDIT--I corrected this at the bottom. .021 is the recommended gap, so I have been running these plugs straight out of the box at too large of a gap all this time.:hat:
 
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It should be, but technically speaking, opening them up will cause more stress on your electrical system, potentially wearing stuff out quicker.

Besides, those BRP engineers are pretty good at what they do, so if they say .021, guess where I am gapping mine... :reddevil:
 
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You should always check the plug gap, even on new plugs...

yea ngk are always dead on...just wondering if it was ok to open em up a lil

NGK's own website tells you to gap your plugs even when new. There is no "one and only proper gap" for a given plug. A particular plug may be used in many different engines, each with its own ignition system, each having its own gap specified by the engine manufacturer for that engine/ignition.

Some NGK plugs come with a dash number indicating the factory gap on that plug (-10 means 1.00 mm, for example). However, there's no guarantee this is the proper gap for YOUR engine just because it uses that plug. Nor is it a guarantee that the gap is properly set, despite what the NGK factory may have intended. That's why NGK specifically says to gap your plugs.

In fact, here is an excerpt straight from their website:

Q: Do I need to set the "gap" when installing a new set of plugs?

A: Maybe. A spark plug part number might fit hundreds of different engines from many different manufacturers. Although the NGK factory will set the gap to a pre-selected setting, this may not be the right gap for your particular engine. The incorrect plug gap for your engine can contribute to a high rate of misfires, loss of power, plug fouling, poor fuel economy, and accelerated plug wear. It is always best to check the gap against the manufacturer's specifications.(emphasis mine)

...and:

While it is a popular misconception that plugs are pre-gapped from the factory, the fact remains that the gap must be adjusted for the vehicle that the spark plug is intended for. Those with modified engines must remember that a modified engine with higher compression or forced induction will typically require a smaller gap settings (to ensure ignitability in these denser air/fuel mixtures). As a rule, the more power you are making, the smaller the gap you will need.(emphasis mine)
 
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I'd check the ENGINE manufacturer's specification for plug gap...

...and use that. Every engine and owner manual I've ever seen has a spec for plug gap.
 
OOOPS!!! you are right. Plug gap is supposed to be .021. I usually run .022 or so. Gonna fix that in all previous posts so as to not confuse anyone.

ALSO!!! Another mistake I made. The plugs come pre-gapped at .027, not .021, so I have been running them overgapped straight out of the box for years. :rofl:
 
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lol....your probably not the only one... i got the info straight from NGK, you put in the plug and the motor, and year it tells you the gap... kinda cool
 
Ngk..?

The NGK BR8ES comes gapped about .032 because it was not primarily designed for the Rotax motor. The plug was originally designed for a dirt bike I believe.

Like all the info quoted above, you should always check the gaps on your plugs before use and don't take anything for granted when you are told they are pre-gapped, even on your car.........:cheers:
 
i was getting a lil bit of build up on mine, thinking about opening them up to about
.038 think it would be ok?

A bigger gap normally means a weaker spark. Don't do it. You have a limited amount of spark energy, and when you open the gap... you may not have enough power to fire it while the engine is running.

If you have build up on the plugs, either run a hotter plug, or re-jet the carb. Just like rain going down a mountain... the fuel going though your jets will eventually erode them. Replacing the jets with the factory size, (if the carb is old) will normally take care of a slightly rich issue.

Also... 2-stokes eat plugs. No way around it. If you put oil into the combustion chamber... it will get on the plugs.
 
Just a quick physics lesson, and reflection on my above statment.....



OK... your plugs. When they spec the gap, there are a bunch of reasons for that. The big one is because of the available firring energy.

So now you say... "So, I want a bigger gap, and when I open it up to .038" it fires fine."

OK, sure it does. But first ask your self: Why do I need a bigger gap? What am I trying to achieve?

If it's to get rid of build up... it's the wrong thing to look at. Heat range to clean the plug. a "Hotter" plug will burn off the build-up. But the "Heat range" of a plug has nothing to do with the spark energy.

If you want to open it up because you think you aren't firring all the fuel... well... unless you are using a MSD type ignition, you only get one chance to fire that jug, and honestly, if you think you have a high speed miss, then closing your plug a little is probably what you need to do.

I Know most of you are about ready to say... "your an Idiot." I agree (that I'm an idiot) but listen to me on this.....


OK... so the spec for your Doo's is around 0.022". When you pull a plug an look at the spark, it really isn't that bright. This is our starting point. So... how does a spark actually occur? An energy source has to create a potential in 2 places. One is a positive, and one is a negative. Now, to actually get that spark to jump the gap, you must "Ionize" a path between them. That will let the little electrons to flow across air. (normally not conductive) So our weak little spark plug can do that while you are looking at it. That's all fine and good, but that's at 1 bar of pressure. Now, in your engine (if in good condition) while running at top RPM's... you probably are getting right around 180 psi in the jugs just before fire. That's about 12.25 bar. So, if we compress a gas, all the little molecules get squeezed together. Normally you would think that's good because the electrons are closer, and you can pass more power. WRONG !!!! it's actually the opposite. Remember, air for the most part isn't conductive, and now you have to ionize a path though 12.25 times the junk. This is equivalent to trying to fire a gap that is 0.260". If you open the gap 0.038", that is the equivalent to 0.466" while running.

So the question is... do you think you can fire a plug with almost a 1/2" gap? (I don't)


This kind of thing comes up on this board every once in a while... but we see it all the time on the Hot Rod, or tuner boards. Guys will bolt on a supercharger, or turbo, and then want to know why their engine shuts off as soon as they see 8 lbs of boost. (they get a static plug gap of about 2 to 6 inches)
 
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correct gap...?

So you are saying that 0.021' is the correct gap for ALL rotax engines. I have twin 717's. Is this the gap I should be looking at?
 
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I found them at autozone for a bit less than seadoo dealer, ngk in the yellow box, I can walk to the auto store for mine and I set at 0.025 just cause I have a wire guage for that. I burn premix in the start of every season and sometimes those plugs get yukky so I put in a pair from last year, those oily ones I put back in later in the season and burn them clean and save them again.
 
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