Scooterotica

i'm using a Li type cowl with cutout which blows cool air over carb manifold for originality, which cowling is the best for cooling, as anyone tested with egt unit and different cowls

there was a lot of threads on egt units, what's everyones verdict, do we know an ideal running temp for a rt 220, and are we agreed on mounting the probe 100mm from cylinder exhaust outlet.

does the probe affect performance by affecting flow, and how far do we insert probe :shocking:

I doubt if the type of cowling would affect the egt it would perhaps have more of an affect on cht which is slower to react to engine temps. An egt reacts to changes almos instantly, eg. if i go from 1/2 to full throttle when accererating the egt can drop 150 to 200 degrees in a matter of seconds when the main jet comes in tho play.
It has been said before but it is very helpful when setting up and is a great indicator of what is happening and to warn of any unforseen changes while you are riding day to day eg. air leaks.
Mine runs between 400 and 600 deg. depending on throttle position if it goes above much 650 that is the start of the danger zone.
The position of the sensor is 100mm but check with manufacturer.
I see from your avatar your a brummie, if you go on the mid scoot runs i could show you mine egt that is!
Russell

thanks, confirms most of what i thought, but better to be safe than sorry, yeh from brum but currently in exile in france

Thermo coupling should be between 4 / 5 inches from piston

ian "taffspeed" recomends the indian cowl as the cut out on the right were the air escapes from is larger , the flywheel cowl must be very close to the fan as well as close as 1mm and there should be no gaps between the 2

fitted koso egt the weekend, 100mm from piston , seems fine, gently bent flywheel cowl as close to flywheel as poss, snug fit between 2 cowls , will see if a few tweeks make any difference to egt reading at different revs etc. impressed with koso unit btw

Vibration kills these things. Mine just went out again right after I posted how happy i was with my westach. Same as before I reckon. the needle just randomly flops back and forth at the low end of things. I know I'm not running that cool.

shocky wrote:ian "taffspeed" recomends the indian cowl as the cut out on the right were the air escapes from is larger , the flywheel cowl must be very close to the fan as well as close as 1mm and there should be no gaps between the 2

Hello Shocky

I have a MEC crank in an S3 Li125 engine with a SIL GP flywheel. On my first long test ride one of the bolts holding the flywheel cowl came loose and the flywheel cowl shifted inwards under tension from the other bolts and began rubbing on the tips of the flywheel blades (what a horrible noise that made). The heat from the friction burnt off all my lovely new paint in a crescent shape.

I initially thought it was because I had used an older, shallower flywheel cowl but after ordering a stainless replacement I see they are both the same height.

When I fit the replacement I see there is around 1mm between the cowl and the ends of the blades. I removed and re-fitted the flywheel just to be sure.

Is this normal? There is currently no rubbing when I kick it over.

Best regards

Ben

sound about right do you have the deeper cowl and the flywheel with larger fins? im sure the problems some have had are they fit a bigger cowl with a short finned flywheel which i recone just recirculates some of the air around the flywheel in a vortex where as if everything is close it will "pump" the air through properley ,in my line of work hydrolic (water or oil) pumps are used alot when the pump wears or a bit brakes of the pump pressure is reduced on safety critical machines the flow is measured and the pump speed can be increased to compensate, a sudden drop in pressure or increase in speed will flag up so the operator knows theres a problem and the part can be replaced ,it sound complicated but were as we used to replace pumps on a maintance sheduale (sometimes there was no wear in them ) we can now replace them as they start to fail which saves alot of down time and needless expence for the customer .... sorry to bore you but i think the 2 principles with reguard to flow are pretty close

Thanks Shocky.

The engine now runs fine with the new stainless flywheel cover fitted.

Ben