Originally Posted by rockhopper
I'm not sure everyone here is picking up on your location. AUS can be a very hot, dry, place with mega fine dust. Very different than the riding conditions of the northerners.
Good lookin out RH!
Fabian, I thought I detected an Aussie sense of humor!
Interesting to note that in a 2 smoke the proper gasoline w/ the proper jetting and mix ratio will provide a burn temperature that helps regulate engine temperature. If all are not in place it doesn't run right and will likely run hot!
The more oil the leaner the gas and vise-versa. So if your not going to rejet you need to find the right mix ratio to get the proper air fuel mixture for good power and proper cooling while still getting sufficient lubrication.
This can be done as follows
Buy a box of spark plugs, a qt. of 30w oil, 87 octane (unless it has like 9:1 compression or better and it doesn't unless you made it so) gas, a few gas cans and a lb. of patience.
Find a friend (someone who'll share the patience you bought earlier w/ you) and place where you can run a mile or two (preferably 2) full throttle. w/ parking lot on both ends for your chaser vehicle.
Warm your bike up be for you test.
Start w/ the highest oil to lowest fuel ratio you think you might need and work the other direction.
Put a new plug in w/ the engine warm and run it full throttle for the 1-2 mi. Pull in the clutch and kill the motor. Pull the plug and "read" it; your looking for a dark blond color lighter is lean (gas) and darker is rich (gas).
If it's really off and running poorly there can be conflicting readings. But if your bike is already running pretty good then your likely pretty close and this is not a daunting task.
Get it as rich (gas) as you can w/o fouling the plug and you've found the proper mix ratio for your set up and you can now pick up a good synthetic that falls at or near your new found ratio.
Between ratio changes you'll need to completely remove all fuel from the crankcase and fuel system i.e. drain tank lines and carb then crankcase (in that order). Crankcase is blown out by removing the spark plug, releasing the clutch lever, and while holding in the kill switch (very important so you don't fry your cdi) pedal around a bit spinning the motor all the while pumping it free of fuel.
It, as previously stated, is important that you stay w/i the oil manufacturers recommendations. Also to get the best power and life outta your motor it's important to run it at the proper temperature by properly adjusting air fuel mix and oil ratio and exhaust and air intake etc. etc. You can run your motor lean on fuel and heavy on oil and not have it seize up but not the other way around.
It is also possible w/ hi fuel to lo oil (100:1 and similar) ratios to run your bike too rich (gas) and still have plenty of oil to lube.
P.S. you can do the same "throttle chop" method to adjust your needle height once you have your o/a air fuel/oil mix ratio determined.