What plug to use

[Ashmy19gasgas]

The manual started either the denzo or ngk br9eg.
My ec300 went back for warranty work and it came back with a br8es!! I was told the mechanic says it will run a lot better using the 8es!
Can anyone shed any light on this?
I did run it today for a quick hour and it ran just fine by the way

 

[Doc Brown]

No clue what model year your bike is, 300EC 2018 and 2019 need a NGK BR8EG spark plug. a NGK BR8ES is not the right spark but it will work fine.

The EG type is the one with the thin center electrode while the ES has a standard center electrode. The EG is less prone to plug fouling and has (allegedly) a stronger spark hence better combustion.

 

[Davehuge]

As Doc Brown says...

BR8EG is the correct plug, BR8ES will work fine and no risk of damage to the engine. It's a much cheaper plug.

By the way...I always carry a spare new plug and plug spanner in my bum bag, just in case although I've never had to use it yet.

 

[Ashmy19gasgas]

Sorry chaps it?s a 2019 ec300!

I e always used br9eg and that?s what the manual says to use. But like I?ve said, for whatever reason, the mechanic, who by the way races for gasgas uk advised to use br8es!

 

[SS109]

On NGK plugs, lower the number, hotter the plug. A hotter plug, as long as it doesn't cause a hot spot which leads to pre-ignition detonation, will foul less than a corresponding cooler plug.

The BR8ES and BR8EG are completely interchangeable. The only difference is in the electrode materials. Here is what I pulled on them...

S series plugs: These are standard plugs with copper cored centre electrodes. A copper core offers superior heat conductivity hence heat is removed from the firing end of the plug and 'hot spots' are prevented - these can lead to pre-ignition. A copper core also allows a longer insulator nose to be used - this protects against fouling.

G series plugs: These feature a smaller diameter centre electrode tip made of nickel alloy. The smaller diameter means a lower voltage is required to produce a spark. As the tip is made of conventional Nickel Alloy the service life is reduced. Best suited to applications where plugs are changed regularly.

That said, I have only used the S version plugs in all my bikes. That's Honda, Yamaha, Suzuki, Kawasaki, and GasGas bikes and I have never had a problem. That includes my old '74 Yamaha RD350 race bike I had many years ago. I tend to replace the plug once a year whether it needs it or not. Good jetting and a properly maintained engine are keys to good plug life.

 

[Doc Brown]

Sorry chaps it?s a 2019 ec300!

I e always used br9eg and that?s what the manual says to use. But like I?ve said, for whatever reason, the mechanic, who by the way races for gasgas uk advised to use br8es! ������

If you are in Europe, the spark plug the manual says you should use is a NGK BR8EG. I wonder what owners manual you have, but for sure not the same I have.
If you are in the US, well, there may be a different owners manual though I see no reason for that.

This is a screen shot of my 2019 owners manual...

 

[Davehuge]

In the UK...

BR8EG = 6 GBP
BR8ES = 3 GBP

G version is specified by GasGas but I've heard many people using the cheaper S version without any problems. I very much doubt anyone would see a difference in performance.

The S version is a standard spark plug, the G is a competition/racing spark plug which would be expected to be replaced more often.

Important points to note...

G version = Sparks at lower voltage, less prone to fouling, shorter service life, more expensive.

S version = Longer service life, can foul easier, cheaper.

If your bike is properly jetted and you're using a good quality 2 stroke oil I'm sure the S version will be fine, although as I said before I always carry a spark plug anyway!

 

[(F5)]

I use the G and replace it yearly.

 

[Neil E.]

I have to stick my tongue out at F5 and say I've only used two BR8EG plugs in 8 years of operation. The original Denso spark plug was total garbage and only in the bike for a few weeks. I am on my third piston and second connecting rod.

 

[Davehuge]

I've only used two BR8EG plugs in 8 years of operation.

Just out of interest, approximately how many running hours over the 8 years?

 

[Jacob 'Berg]

I have to stick my tongue out at F5 and say I've only used two BR8EG plugs in 8 years of operation. The original Denso spark plug was total garbage and only in the bike for a few weeks. I am on my third piston and second connecting rod.

Damn, two con rods over the course of three slugs? That seems excessive.

 

[(F5)]

Yes wording perhaps? Could be after 8 years he decided to change the rod, so hes on his 2nd?

At 11yrs old my main brg failed do I changed the rod at the same time.

 

[Doc Brown]

Just out of interest, approximately how many running hours over the 8 years?

I'd say about 30

However, if the TO uses ES or EG plays no role. I just wonder how his manual says use a BR9. It should read BR8

 

[SS109]

I'd say about 30

However, if the TO uses ES or EG plays no role. I just wonder how his manual says use a BR9. It should read BR8

We cleared up that he should be using the 8 and that the S version is good as well. Maybe it was an early manual misprint or the manual was later revised?

 

[Neil E.]

Damn, two con rods over the course of three slugs? That seems excessive.

I got some dirt in the engine and had to do a piston and rod at 50 hrs. So I'm currently on the second rod and it got the second piston at that time. Then another piston at 250 hrs which makes the third. I'm at about 375 hours now so I expect to do the piston again at the end of 2019.

 

[Doc Brown]

We cleared up that he should be using the 8 and that the S version is good as well. Maybe it was an early manual misprint or the manual was later revised?

Yep, I have read the thread. Sure, could be a an error in the manual, but I doubt it. But no problem, he can run what he wants.

 

[Stewee64]

The core thickness has already been mentioned but It's Interesting to see the difference in length of the 2 approved/suggested plugs?
Denso is on the left.

 

[Davehuge]

In all my years and many different bikes, I've always used NGK plugs, I wouldn't use any other brand.

I can't comment on Denso or any other brand, maybe they're as good, better or worse, it's just I know and trust NGK. It's my personal preference.

All the best, Dave

 

[Doc Brown]

The core thickness has already been mentioned but It's Interesting to see the difference in length of the 2 approved/suggested plugs?
Denso is on the left.

I see no difference in length.

Like Dave I only used NGK plugs in 40 years of riding. Possibly others work well too, I'll just never find out...

 

[barossi73]

240hrs due for 4th piston,fouled 1 denso at beginning with stock needle,switched to NEC/NED needle and NGK plugs,havent had a problem since,but usually i change plug @30/35hrs although i ran 1 for the entire life of the piston no probs (for me thats usually@60-80hrs 200)
I do carry a spare on long/solo riding
Different 2t oils seem to vary a bit in how much residue accumulates on plug,and plug colour