Here's what PO left inside engine with two cracked lifters. Likely caused by a rush teardown and misaligned chain sprockets. Almost parted it out. Had a BMW airhead mechanic at dealer install new cam and my crank in a good used block.
As for performance, I rode it only about five miles when I knew there were major problems. Had several other bikes, so I kept it as a project. With new cam it came alive, still hesitated under 3k rpms. Installed venturied inlets. Hesitation solved, IMO. The tapered inlet manifold accelerates the mix. Some would say it also limits WFO rpm if racing on a two and half mile oval. Don't spend much time over 7k as I want to keep riding this bike. Like all airheads, 4/5k is saweet.
These being real world rider bikes, bikes which we can ride across the country in relative comfort/speed/reliablity, throttle response roll-on from idle jets to mains is improved with the venturied effect, in my opinion. The Dels squirt that fuel, the narrowed inlet accelerates it, and the 64 degrees of overlap of 336 sucks it right out the rear end. All the best to your efforts keeping another airhead on the road. Had no idea over twenty years back that this bike would be such a source of fun times.
Caveat, I'm not expert in any of these areas, just an amateur wrench, loves to use the hands, and does a lot of research before going in.
Last edited by 8ninety8; 03-27-2012 at 10:12 PM.
Reason: wrong number