Fuel:oil mixture for RM 125 B

[SON]

Your G looks good, same as my previous post if you can ride the bike like it was designed run a 9, the S is OK but the 9EG or 9EGV is better,
If the engine is fairly fresh and ridden regularly run the good oils at 40:1.
If its not so fresh run synthetically fortified oil at 32:1
If you run mineral oil run it at 20:1 as was recommended.
If you don't have X ray vision I suggest some plug chops at quarter, half and full throttle

[Ted]

Good advice

[SON]

Your G looks good, same as my previous post if you can ride the bike like it was designed run a 9, the S is OK but the 9EG or 9EGV is better,
If the engine is fairly fresh and ridden regularly run the good oils at 40:1.
If its not so fresh run synthetically fortified oil at 32:1
If you run mineral oil run it at 20:1 as was recommended.
If you don't have X ray vision I suggest some plug chops at quarter, half and full throttle

For Dirttrack and high revs run a 10

[Digga]

Thx SON, much appreciated

[Lozza]

NGK have Racing on the box
They are a dearer plug, not from the standard range

a proper race plug is a platinum/iridium NGK R7282 standard fitment RS/ TZ 125 and 250( some kx250/125). They add 0.5-1hp across the range on a 85cc

http://www.fastech-racing.com/ngk-r7282-105-racing-spark-plug.html

[oldyzman]

The BR8ES referred to is a resistor plug at approximately 4.8K OHMS. Not to be confused with Race... I recently purchased B10ES for a 250 air cooled running AVGAS and this had racing written the box, but i dont believe its a race plug. Are we better of using a B8ES or B9ES than the BR...?

[Ted]

I was using B8 ES for years, then BR8ES, now BP 8 .... Whatever my mate has in stock at time. Can't notice any difference.

[Lozza]

An ignition needs either a resistor in the plug (the R in the model code) or in the plug cap not both. The spark will be very weak with resistor cap and plug.
If you can't notice any difference in plugs or plug gap your a long way off optimum tuning. A wider gap should (from memory) work better at low end and smaller gap top end. With heat range if the engine is working better the longer it's ridden the plug is to cold if it gets slower the the longer it's ridden the plug is to hot..   

[oldyzman]

Interesting Lozza,
What can happen if the bike has no resistor in the plug or in the cap?

[Lozza]

Run it and find out 







not much just a weaker spark the resistor makes the ignition work harder therefore it easier for the spark to jump the gap

[JohnnyO]

Interesting Lozza,
What can happen if the bike has no resistor in the plug or in the cap?

PVL ignitions have no resister in the cap and they stipulate to use a non resister plug

[Lozza]

Model T Ford had a service guide recommending you install a coat button in line on the high tension lead when oil consumption was high. The resistor is the basis for all those "spark intensifiers" for sale on the shelf  right next to the snake oil. 5k Ohm resistor plug or cap is going to increase the voltage in the secondary of the coil before it will jump the gap.

[80-85 husky]

Whats this got to do with the fuel oil mix of a RM 125 Keh??

[davidmc]

P  means Projected Core for use in 4 Strokes to aid cooling of the Plug, (exposed to incomming charge),
first seen in TT500 Yamaha.
DO NOT use in a 2 Stroke, too close to top of piston and may burn a hole in it!

[Ted]

We had no problem at the CRC ( where it was revving its tits off ) or Nats with a BP, but I will ask the question. Thanks for the heads up.