what oil?

[aussieidiot]

here we go again......


my reason is that the cost of decent bike oil (repsol, motul) is nothing compared to car oil of comparable quality.

but also, name a car that runs a wet clutch.....

[jeffcoslacker]

Like I said in the last one of these, Shell Rotella is made for OTR diesel trucks, but lacks the friction modifiers that don't play nice with wet clutches, comes in several grades (I use 15W40) is ecellent at suspending particulates (like diesel carbon or wet clutch wear debris)and is pretty damn cheap by the gallon at Walmart and others...myself and many other cyclists have found it to be a very good alternative to MC specific oil...

[jeffcoslacker]

Originally Posted by bjboertje

i just want it for the sound. i think the side without the muffler on it sounds awesome. what does it take to re-jet the carb and open the intake?

Sorry, I lost my bead on this thread somehow...

Doing exhaust "just for sound" is not really adviseable on a bike (or a carb'd car for that matter) there are two issues...backpressure (the amount of restriction at low flow) increases scavenging (an effect which helps fill cylinders with air faster for better torque and throttle response in the low rpm ranges)...and the additional flow out the back end creates an imbalance in relation to the amount of flow the stock airbox can deliver...the imbalance screws with the venturi effect of the carbs, making the mixture wrong. An engine with wide open exhaust and a restrictive stock airbox and carb tune will run lean, and cook the pipes and make exhaust valves run hot and possibly burn...

To remedy, you need to improve airflow into the airbox, usually done with addition of a K+N type filter and possibly a less restrictive box design, along with a re-jet of the carbs, which includes larger main jet orifices and new needles which can be adjusted up or down to fine tune the amount of fuel the jets meter through the range of throttle opening...it's time consuming work if you have multiple carbs because everything must be resynchronized and correct needle positions can be trial and error...that's why fuel injection is so nice, all you need is an interface and some fuel maps to try until it works fine, no messing with mechanical settings...

Stock engines anymore are already tuned way lean for EPA appeasement...doing anything to make it worse is asking for trouble..do it right if you're gonna do it.

[richtazz]

Originally Posted by jeffcoslacker

Like I said in the last one of these, Shell Rotella is made for OTR diesel trucks, but lacks the friction modifiers that don't play nice with wet clutches, comes in several grades (I use 15W40) is ecellent at suspending particulates (like diesel carbon or wet clutch wear debris)and is pretty damn cheap by the gallon at Walmart and others...myself and many other cyclists have found it to be a very good alternative to MC specific oil...

The reason that oil works in bikes is because it doesn't have the friction modifiers.

[aussieidiot]

Originally Posted by jeffcoslacker

...that's why fuel injection is so nice, all you need is an interface and some fuel maps to try until it works fine, no messing with mechanical settings...

fuel injection on bikes is a bit more primitive to cars. they don't have the capacity to vary the fuel according to the oxygen sensor enough when aftermarket pipes are fitted.

i was told that the ECU can only change very small amounts (if at all) which would be more inline with atmospheric conditions rather than larger changes.

the new gixer range is supposed to have a better tolerance than the others.

oh and power commanders are fricken expensive to buy and set compared to new jets


back to the oil debate......

$50aus for my oil. $10aus for cheap shit supermarket grade "motor" oil
thats $40 per 6 months or 21 cents a day. why could you be bothered complaining.

relative side note. i had an old tradesman ask me why i change my oil in my car every six months when he's been driving over 100,000 k's on the same oil in his F100. he thought he was saving money by not changing the oil. the truck was so slow and hard to drive. one day i paid for new oil and changed it for him. suddenly it had some torque. and he wasn't wasting money on as much fuel either........

[jeffcoslacker]

That's why I said you need an interface (power commander or similar) to modify it's map. But compared to the labor cost of having someone remove multiple carbs, disassemble, replace stock needles and jets, re-install, road/dyno test, R+R as many times as it takes to get it right, carb synch, etc...the cost of a power commander still wins, I think. And the user gets to mess with it and tune it to his satisfaction, not some wrench who doesn't know how it feels when YOU ride it...

[jeffcoslacker]

I was just up at the chain auto parts store, and noticed they carry Castrol MC spec motor oil 10w40 and 20w50 for $3.59/qt....pretty reasonable as MC spec oils go. About the same as the factory branded oils at most metric bike dealers, a little less...SG/SH rated but no friction modifiers.