48 HP dyno chart for stock stroke 500 domni racer

Brians 500 with all the JS internals and some mild porting.

Very nice,but mixture looks very weak up to 7000. Is that accurate?
What is the camshaft?

Its a JS2 cam. I'll ask him about the mixture. Don't want it lean.

The green line down around the 10 mark level means richer (not leaner).

jseng1 said:

The green line down around the 10 mark level means richer (not leaner).

Click to expand...

Yes. Assuming it's petrol around 12.5 is best for power.

jseng1 said:

The green line down around the 10 mark level means richer (not leaner).

Click to expand...

Sorry, , I looked too briefly and it was 2hrs past my be time.
I will havet to check how the JS2 compares with the 4S I used in mine for a few races.

jseng1 said:

Brians 500 with all the JS internals and some mild porting.

Click to expand...

Nice result.

About 20 years ago now I dynoed my 500 after a couple of years of tuning.

the plot is on here somewhere.

Best I got was 51 bhp rear wheel at 6100 rpm. But I still had megaphonitis very bad under about 4200 rpm.

This curve is much better lower down and also continues well over 7000 whereas mine was flat from 6500. I didn't have a Lambda meter back then. This engine would be much more ridable than mine especially if the rules said a 4 speed box. A very nice result.

My bike had a PW3 cam and 10.25 :1 GPM pistons. Mk1 30 mm Amals, home made exhaust, porting by a NZ guy who did a lot of speedway cars and bikes. Pump gas.

Funnily enough my bike is sitting in my garage with a 50 % assembled engine with JS cam and lightened pistons etc fitted. And a intertial dyno is parked in my garage. But I'm not much into racing these days.

I found my old plot from Jan 2009. Ignore the Daytona plots. They are from old factory results.