NickZ
VIP MEMBER
- Joined
- Oct 31, 2018
- Messages
- 489
I have been trying to get to the bottom of a performance issue with my 72 Combat Interstate. Performance seems fairly normal in 1st - 3rd gears but in 4th gear the bike does not accelerate like it should, struggling to get past 4000 rpm. I read the thread on this subject posted by @ILLF8ED starting in 2015. As suggested there, I have eliminated fuel flow and valve timing as causes and have moved my focus to ignition timing. This bike, as did ILLF8ED, has the RITA electronic ignition.
What I am seeing with my unit is that when I set it up as specified in the Mistral Engineering documentation, I get the 20 deg BTDC advance at 2000 rpm as expected, but the advance does not top out at 28 deg at 6000-6500 rpm as the documentation suggests it is supposed to, but has increased up to around 40 deg. At 4500 rpm it is around 36 deg advance.
2 questions:
1- Could the excessive advance at these higher rpms be the cause of degraded high end performance?
2- Are these advance readings "normal" for the Lucas RITA AB11 ignition?
What I am seeing with my unit is that when I set it up as specified in the Mistral Engineering documentation, I get the 20 deg BTDC advance at 2000 rpm as expected, but the advance does not top out at 28 deg at 6000-6500 rpm as the documentation suggests it is supposed to, but has increased up to around 40 deg. At 4500 rpm it is around 36 deg advance.
2 questions:
1- Could the excessive advance at these higher rpms be the cause of degraded high end performance?
2- Are these advance readings "normal" for the Lucas RITA AB11 ignition?