- Wed Apr 01, 2015 4:30 pm
#46026
Patrick. You've just fitted a new Mk1 Concentric - I wonder....
I had endless problems on my 1996 500 when I fitted a new concentric (Mk2 but the principle is the same). It idles well but got worse as the throttle was openeed - coughed, missed then died, spluttered as yours seems to do. I too thought it was electrical - expensive. Then I thought it was cams (don't ask). Then I thought it was the jets (bought and tested many).
Then, on the BritBike website, in an Amal tuning guide, I found this statement:
"Crisply open the throttle. If the motorcycle stumbles, has a rhythmic misfire, but slowly picks up rpm, the Air/Fuel mixture is too rich. Install a Slide with a higher number (leaner).
— As above, if the motorcycle spits, has an erratic misfire or just stops running, only to pick back up again as the Slide is closed, the Air/Fuel mixture is too lean. Install a Slide with a lower number (richer)".
That was a breathe of fresh air. I had bought the carb from our hosts with the standard 3.0 throttle slide fitted. So I changed the slide to a 2.5. Instant success!!!
So, are you sure the slide is correct?
ChrisD