Scooterotica

I like to use the Chiselspeed m-tech unit as it has so many variable settings. When i first got mine, i fitted it, fired the race scooter up on the dyno, attached the strobe gun and did something like a dozen or more back-2-back runs.

I just kept the motor running and clicked through each setting, whilst monitoring the strobe marks, dyno graphs, and cylinder temperatures for each one. You can see the strobe marks change as you click each setting, so you can pick the one that suits your engine best.

Although some people like to use these units to 'gain bottom end'....and set static at approx 25 deg, to tick over at 22/23-ish, and to fully retard to about 18-ish (depending on engine setup and ign unit used)......i feel that it generates too much heat at bottom end and low rev riding, and contributes heavily to piston holes etc.

I ended up running my race engine at 19 static, 17 tickover and 10 fully retarded at 10k rpm. Most 'fast road' scooters i set up are set at approx 21/19/12 degrees respectivly. With this, you can litterally screw the c**t out of the scooter and then park up and put your hand on the cylinder cowl and it will be a nice temperature, even on cast iron cylinders.....ask Lam46.

The lads that i dynoed for the coast 2 coast meeting (Philly Hindle, James Chrichton etc) all have their variotronics set (by Jimmy) to come back to 12 degrees, and those guys finished in the top 5. It puts all the heat into the exhaust and keeps the top end cool.

Too much advance at high RPM kills revs and generates heat as the power cycle is fighting against the early spark/ignition.....reducing that lead time encourages a higher RPM limit and reduces heat build up.

Hi
Interesting post. I've read about this, putting the heat into the exhaust by using retarded timing. In the article i read, it actually suggested that very retarded timing will cause high EGT's even thouh the bike is running safe as most of the heat is going straight into the pipe. Is this what you have found?
Also, i spoke to another very respectable tuner who said only advance your timing by 2 or 3 degrees when using agusto's or similar units as it does create too much heat even at low revs.
Pete

You would be best off using one of our Mtech adjustable boxes,then you will have the ability to adjust the amount of retard to match your engine,it has 16 positions starting at the same as the agosto 6000 at one end,going on to pass the 8000 at the other end of the scale,this way you dont find that you bought the wrong box and have to go get another one to get the job sorted.cost is £80 and they are now available online as our website is finally up and running,www.chiselspeed.co.uk Chisel

I personally feel on a standard/mild tune upto 7-7500 revs if squished, compression ratio correct and jetted right you can get away with the agusto 6000 and i do without a problem, running a standard barrel set up, you have,nt got the bhp and torque to pull 16-12 degrees of retard, i think 18 degrees max, but then someone will point out that i,m wrong, good!....
you,d better be clever to know more than me lol..........