Team GPR

**mr bucketracer** · 6th January 2016, 20:07

Originally Posted by Bert

Apparently 14.7 isn't the magic number for peak power.. 12.6
Need to redraw the wall graph.

For install, this is worthy of reading
http://wbo2.com/lsu/LsuInstal.pdf

thats good as my bike is at that now

**husaberg** · 6th January 2016, 20:31

Originally Posted by Bert

Apparently 14.7 isn't the magic number for peak power.. 12.6
Need to redraw the wall graph.

For install, this is worthy of reading
http://wbo2.com/lsu/LsuInstal.pdf

Yamaha did some papers 20% rich over the correct mixture, You will get a higher flash reading at STORG but it will fade after onlya few seconds. (THis is all air coooled tech)
20% rich will still fade, only less so. 2 stroke air cooled are partially petrol cooled.
I have posted the paper on ESE (i think?) and robinsons, Camerons and maybe jennings take on it as well.

Yamaha during the sixties found a correctly fuelled air cooled engine HP fell from 30 cold to 23 HP when tested hot.
Where as a over rich mixtured one began with only 27 yet when hot still made 25hp.
Of course the figures were not as good as a water cooled ones lesser power fade.

**Bert** · 6th January 2016, 20:33

Originally Posted by mr bucketracer

thats good as my bike is at that now

So it looks like mine could be a little richer.
Have a read of the PDF it does talk about twostroke positions.
Somewhere in ESE they talk about sensor placement and further tricks.

**richban** · 6th January 2016, 20:48

Originally Posted by Bert

Apparently 14.7 isn't the magic number for peak power.. 12.6
Need to redraw the wall graph.

For install, this is worthy of reading
http://wbo2.com/lsu/LsuInstal.pdf

Holy god no. 14.7 on a 4 stroke single? Air cooled? 12.8 at peak toque should be your happy place. If it goes anywhere past 13 at peak power you could be getting things quite hot. Best way to use them is to have it data logged along side the toque curve. Really easy to see fuelling issues then.

**Bert** · 6th January 2016, 22:43

Originally Posted by richban

Holy god no. 14.7 on a 4 stroke single? Air cooled? 12.8 at peak toque should be your happy place. If it goes anywhere past 13 at peak power you could be getting things quite hot. Best way to use them is to have it data logged along side the toque curve. Really easy to see fuelling issues then.

Ok a lot to learn then...
Scott has upgraded the dyno with a AF kit, works very well. Just a case of ignoring everything that Google has to say and sit down and learn things correctly.

**richban** · 7th January 2016, 07:11

Originally Posted by Bert

Ok a lot to learn then...
Scott has upgraded the dyno with a AF kit, works very well. Just a case of ignoring everything that Google has to say and sit down and learn things correctly.

I think 12.8 was what I used to work to on my old FXR. All engines are different of course fuel, and ignition timing will have an effect. But 12.5 to 12.8 on an air cooled was good running av with quite a lot of ignition at peak. Water cooled 13.2 ish safe. Just remember to heat the probe for quite a while before using it. Or it will not last long. And Avgas will kill it quicker, 2 stroke will kill it even quicker. Good tools to tell yah what is happening. Also in a single you have to watch out for exhaust reversion. Looks like really rich all of a sudden on the AF. You go chasing jetting only to find its the pipe that is causing it.

**Bert** · 7th January 2016, 07:18

Originally Posted by richban

I think 12.8 was what I used to work to on my old FXR. All engines are different of course fuel, and ignition timing will have an effect. But 12.5 to 12.8 on an air cooled was good running av with quite a lot of ignition at peak. Water cooled 13.2 ish safe. Just remember to heat the probe for quite a while before using it. Or it will not last long. And Avgas will kill it quicker, 2 stroke will kill it even quicker. Good tools to tell yah what is happening. Also in a single you have to watch out for exhaust reversion. Looks like really rich all of a sudden on the AF. You go chasing jetting only to find its the pipe that is causing it.

Cool, now for the first question. What is the optimum distance for the probe?

Future reference, standard wiring colours.
http://ricksfreeautorepairadvice.com...sor-colors.jpg

**mr bucketracer** · 7th January 2016, 07:22

Seems my bike staying rich at the top end as well. May try my old pipe , just cheaked rich's dyno chart and not far of the top end 12.8 to 13 from 10 to 13000 , cooler in the shed today so want to see the air changes

**Bert** · 7th January 2016, 08:22

Originally Posted by mr bucketracer

Seems my bike staying rich at the top end as well. May try my old pipe , just cheaked rich's dyno chart and not far of the top end 12.8 to 13 from 10 to 13000 , cooler in the shed today so want to see the air changes

All very interesting.
Well I'll do my man chores and finish the wiring and pop back up.