hi guys i had my 199A runing spot on but when i try 2 start it first time from cold its been taking a good few kicks 2 start her up. once its started and warmed up she start first kick. so i took the plug out to find it had oiled up so ive try ajusting the bing carb thinking it was runing to rich. no change ive been runing it on 40-1 why the new piston as been run in i think it may be to rich so i think ill go back to what i used to 50-1 its not the timming thats spot on got big fat blue spark so do you think it will be the oil mix?

Bondy

given the very low stress and low temperatures that trials bike engines see, 40:1 is a tadge excessive, especially with modern oils. (i presume you use something semi or fully synthetic).

The issue here is the ability of the plug to fire when under load (load = compression).

Oil in the fuel is a good lubricant, but a poor fuel. If the extra oil is not being burned, it remains in the combustion chamber / exhaust and on the plug.

Another point is that when you run 40:1 instead of 50:1 you are actualy running the engine weaker. Weak mixture + cold engine = poor starting.

My advice is to change the plug (ensure it has the correct heat rating) and go back to a more normal ratio.

Be aware that 50:1 is already "on the safe side" for a trials engine.

Dom

hi dom yes ill go back 2 50-1 and change the plug the plug is NGK bp5es wich is the corect plug. ive been useing ipone semi synthetic strawberry. i will drain the fule off and mix some fresh fuel at 50-1 with new plug the new piston as been run in know cheers.

I use 80:1 in my 199A, no problems at all. I thought you were coming out to play today Bondy? Good trial with the Aqueduct lads in Llangollen.

hi mate i was gonner come mate but i had alot on this weekend. is that 16ml 2 evrry litter? i use semi synthectic what oil are you useing? might do 12ml to a liter? when you going out again?