- Joined
- Dec 30, 2003
- Messages
- 3,658
Hi L.A.B.
I would have to agree about the '72-'73 model year breathers being the same no matter which performance engine. The positive identification from Dave's photo is the fins. I see he later found the "C" stamp under the head steady.
Dave,
My opinion again about combats. I see several comments about detuning these engines, but the combat was only made one year - enjoy it for what it is. Keep the high compression and either retard the spark a bit and/or find some leaded race gas. Mine was pinging again recently after putting in a new alternator. One of the club guys suggested the timing mark on the new rotor may not be accurate, so I started retarding the reluctor (Lucas RITA ignition). Got it to stop and I'm using 91 octane unleaded. Not sure about the compression ratio in my combat. I'm using a standard base gasket and flame ring head gasket. Compression is 185psi in the left and 183psi in the right. Engine pulls easily to 6,000 rpms - no further please, I'm not as crazy as I was at 20. My first combat had a real power surge at 7,000 and pulled way above this.
David
I would have to agree about the '72-'73 model year breathers being the same no matter which performance engine. The positive identification from Dave's photo is the fins. I see he later found the "C" stamp under the head steady.
Dave,
My opinion again about combats. I see several comments about detuning these engines, but the combat was only made one year - enjoy it for what it is. Keep the high compression and either retard the spark a bit and/or find some leaded race gas. Mine was pinging again recently after putting in a new alternator. One of the club guys suggested the timing mark on the new rotor may not be accurate, so I started retarding the reluctor (Lucas RITA ignition). Got it to stop and I'm using 91 octane unleaded. Not sure about the compression ratio in my combat. I'm using a standard base gasket and flame ring head gasket. Compression is 185psi in the left and 183psi in the right. Engine pulls easily to 6,000 rpms - no further please, I'm not as crazy as I was at 20. My first combat had a real power surge at 7,000 and pulled way above this.
David
As I get to know my way round the bike I'll no doubt become more confident about tweaking and tinkering. I'm on an intensive course of learning just now :shock: