125-200cc best spark plug heat range for 165

just wondering what heat range the 165 guys are running
I was running an 9 which is standard for a 125 and to help to reduce chance of pre-ignition.
I don't think that is a issue now and wondering about using an 8 or even a 7.
I know another user is running a 165 with a 7 and its cleaner and not fouling plugs

Are you using the Lectron? I have used both the 9 and the 8 with good results but my fuel isn't like yours.

No just the old mikuni ( which I like ) - new mikuni not so much yet

The other guy is using a Lectron and its fouling unless he uses a 7 plug

Sounds like he is too rich on the bottom. Have him pm me so we can work out where he is at and what we can do to fix his fouling problem.

I have found 8 work the best on my 125,144,165.

I deal probably with the same crappy fuel conditions as in OZ and the best results I have is with a 8 plug

Robert-Jan

so I wont melt a hole in the top of my piston by using an 8?

Last time i checked (just 5 minutes ago) there is no hole in my piston top
and I am running this 8 plug for a year now

165 barel, lectron carb, and crap fuel adapted head

Robert-Jan

sweet RJ I have a few spare BR8EG's from the 300 so save me buying more. same set up as you(well nearly just gotta put 165 on, came today!)

Depends mostly how you use it. Be honest with yourself on how you use it. We all use our bikes differently and there is no correct answer for all people and all riding habits. If you torque it around and rarely rev it hard for more than a second, a warmer 8 plug will be just fine (I wouldn't recommend a 7). If you rev it mercilessly, an 8 could most certainly cause a failure. Are you fouling with a 9? If not, there is no need to run the 8. If yes, be certain the jetting is sorted and there is no other underlying issue for the fouling, before trying an 8.

I run a BR10eg for Iceracing where it is revved long and hard, and a BR9EG for moto where it is revved short and hard. I've never fouled either range BTW in 41 hours.