Ben, I asked the tester to back off at 5000rpm or if the powers started to drop off.BigBobPilot wrote: ↑Tue Dec 19, 2017 11:54 pmWhy does the graph stop at 4250 rpm Dan? It's a long way from the red line unless it's a diesel...
Did the rolling road operator back off because the power dropped off or due to the fuelling? If it's the fuelling it needs sorting so you don't lean it out and start melting pistons. I learned the hard way, in the middle of France in my old Scim.
After looking at the above run the tester put a wide band lamda sensor in the exhaust and the reading rose up to 13 as it past 4000rpm, so yes it had fuelling problems at higher revs. He suggested replacing the mechanical pump with an electrical pump as a first step before changing anything like the air correction jets or float levels.
The scimitar was up to 90mph at 4000rpm on the rollers, so not a problem in this country.
I will get the engine back on the rollers in the summer after I have added an electric fuel pump and sorted other more pressing issues such as leaks and draughts inside the car. It is now a lots more pleasing to drive as the timing was tweeked, carbs balanced before the run and most importantly starts easily even in the cold weather. I just play safe and change up before 4000rpm.