Spark plugs in watercraft
- Thread starter tntsuperjet
- Start date
BR9EYA plugs have been used on Arctic Cat snowmobiles for years and still are. Not tech savvy to quote the post about NGK office stating that plug is obsolete. My question is why was the #9 plug recommended in place of the 8's. when changing from an ES to a EYA? I know it's a colder plug but I'm sure they make a BR8EYA.
- Location
- South Africa
We don't have snowmobiles here, maybe nothing else we have here comes with them as OE parts and thus they regard them as obsolete for our country
- Location
- Los Gatos, CA
I run the B8HS solid terminal or B7HS since it is the factory plug, and I've never had any issues.
Nearly every Japanese water cooled 2 stroke dirt bikes use the BR8ES. Newer 2 stroke KTMs run a BR9ECMIX.
Nearly every Japanese water cooled 2 stroke dirt bikes use the BR8ES. Newer 2 stroke KTMs run a BR9ECMIX.
Quinc
Buy a Superjet
- Location
- California
Almost a year later. Anyone notice a difference with plug fouling or anything else after switching?
- Location
- Erie, PA
What plugs should I be running in a 701 with the OCD coil and MSD enhancer? Do I need resistor plugs or is there a resistor built into the coil or enhancer?
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Sent from my iPhone using Tapatalk Pro
Last edited:
Big Kahuna
Administrator
- Location
- Tuscaloosa, AL
What head? Br8hs stock. Br8es am head
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Yami-Rider
TigerCraft FV-PRO
- Location
- Texoma
I haven't noticed really any difference, I just tell my self I'm making more hp lol.
tntsuperjet
Tntperformance-engineering.com
- Location
- Georgetown ca
Sorry I missed a question here.
Why do I recommend a 9 over 8.
Most people have engine mods that increase engine combustion temps and piston heat. Not to mention gas has changed considerably since the design of the engine.
The colder plug will increase safety margin of your engine and reduce chance of detonation.
Specially on engines with higher compression.
If your only running surf type conditions with a lot of low speed run time and idle time you can run a 8.
Most people have engines that are on the edge of seevical on pump gas and they still run an 8 heat range plug.
Why not carry a loaded gun that's cocked in your pocket and throw couple extra things in your pocket at same time sooner or later your luck gonna run out and that gun going off.
It's all the little things like heat range, gas can color, sunlight exposed gas etc that make the difference between years of service and hours of service
Why do I recommend a 9 over 8.
Most people have engine mods that increase engine combustion temps and piston heat. Not to mention gas has changed considerably since the design of the engine.
The colder plug will increase safety margin of your engine and reduce chance of detonation.
Specially on engines with higher compression.
If your only running surf type conditions with a lot of low speed run time and idle time you can run a 8.
Most people have engines that are on the edge of seevical on pump gas and they still run an 8 heat range plug.
Why not carry a loaded gun that's cocked in your pocket and throw couple extra things in your pocket at same time sooner or later your luck gonna run out and that gun going off.
It's all the little things like heat range, gas can color, sunlight exposed gas etc that make the difference between years of service and hours of service
- Location
- Los Gatos, CA
I find for my stock engine, the B7HS runs better and more responsive than a B8HS. The plug also looks better (tanner). But they both work.
Edit: Yes the B7HS is the stock plug.
Unfortunately the B7 is not available in solid top, but the B8 is.
Edit: Yes the B7HS is the stock plug.
Unfortunately the B7 is not available in solid top, but the B8 is.
Last edited:
Big Kahuna
Administrator
- Location
- Tuscaloosa, AL
B7 is what comes stock if not mistaken.
bored&stroked
Urban redneck
- Location
- AZ
My 62t waveraider says BR8HS on top of the head from the factory. Only thing stock I have to look at lol.
- Location
- Saskatoon,SK
I have been running 8eya in my Dasa 1000, pumpgas and 112octane additive, they fouled less than the Br8es and 7es, I will try 9eya and let you know!
tntsuperjet
Tntperformance-engineering.com
- Location
- Georgetown ca
6m6 came with b7, early 61x B7, 62t b8, 96 up should all be b8
May have couple years wrong.
The key here is the change in fuel from the time these engines where developed to today's fuel.
Today's fuel has a lot more additives and methanol added that they didn't have back then.
The new fuel is designed to burn leaving less hydro carbons, meaning it burns hotter. That alone requires a colder plug.
But I have found if I run full spec or DASA carbs I have to go up a heat range in plugs over stock 46 or novi carbs.
If your running full spec you will never get good results with a 9.
They were... originally. Yamaha switched from NGK B8HS to B7HS sometime in the mid-2000s, possibly to meet some crazy EPA criteria, reduce emissions, etc. My '97 came with 8s. My '16 came with 7s but I switched it to 8s.
tntsuperjet
Tntperformance-engineering.com
- Location
- Georgetown ca
Just make sure with stock ignition you keep them gapped .020-.022
Old ignition may need as small as .018
Old ignition may need as small as .018
Quinc
Buy a Superjet
- Location
- California
Now that you all have had 5 seasons to try these others plugs how have your results been? 