Well, thats when a two stroke engine only ignites every second turn on the crankshaft. Happens when the mixture is too rich . Makes a significant sound.
Perhaps this expression (fourstroking) isn
My 2006 270 runs to rich at full throttle where it is four stroking. I guess that a main jet of 140-145 would be fine. I also think that the fuel/air mixture is to rich at idle so the size of the pilot jet may have to be changed to something like 25-27,5.
Anyway I will soon replace the Mikuni with a Dellorto VHST which I think gives superior performance.
A synthetic oil mixture of 75:1-100:1 would be fine after 10 hours of running in. I run at 100:1.
Carl
Hello
I use 2nd gear most of the time in sections. 1st gear occasionally and 3rd gear for long uphills when the grip is bad.
I friend of mine (who is a wery good rider) told me to do a lot of training i 3rd gear as this would improve my skill in using the clutch. Well I
In most european countries the 95 octan fuel contains 5% alcohol (ethanol) so changing from 98 octan to 95 octan means that the bike will run slightly leaner.
The E85 fuel is 85% ethanlol and demands a radical rejetting. 15% petrol is needed for proper coldstarting at low temperatures (less then -10C).
Carl
Compared to my 00 Gasgas my 04 Beta has a more on/off action of the clutch. I have changed gearbox oil from engine oil 0W-30 to gearbox oil 75W90 which I think is a slight improvement.
R9354 is the number if you buy a std carb from a Dellorto dealer. I guess that R9359 is a specific Beta jetting for Beta Motors which should be very similar to mine.
Carl
VHST 26BD R9354 basic jetting for Beta 250/270
main jet: 120
idle jet: S37
needle jet: 272H
needle: D47
throttle cut away: 50
choke jet: 60 ( I feel that this may be a little bit lean)
needle in 4th position from top
idle mixture screw: 2-3 turns. Please note that this screw has reverse operation from the mikuni.
It
Dellorto VHST 26 BD fits stright in and is an excellent carb. More power, no dribbling, no pinging, instant throttle response and a soft throttle spring. Beta use it on the 125
