Keihin CR flatslide racing carbs will work on a street bike. The carbs do not have chokes or enrichener circuits for cold starting. It took quite a bit of fiddling for me to get them to work.
First, the spark. The ignition system should be in tip-top shape for maximum performance. A strong spark at the correct time will successfully ignite a mixture with wider range of air fuel ratios and gasoline quality. This is critical with CR flatslides and the sometimes funky Oregon gasahol. The battery terminals and the battery, engine, and coil grounds are undone, cleaned, lubed with dialectric grease, and retightened every year just before leaving for Bonneville. New NGK iridium racing spark plugs are installed. Nology coils and wires are used. All of this keeps the spark strong.
The lights on bikes sold in the US are lit when the ignition is turned on. This is an idiot concept. Little bike batteries do not have the power to light the lights, run the starter motor, and create a good spark. This is a worse problem with high compression engines. An English light switch is installed so I can turn off the lights when I start the bike. This is a big help. I ordered the switch from London at
www.jacklilley.com.
The battery was replaced every two years before I put on the flatslides and I was not picky about its quality. Now I put in a new high quality battery every year and I trickle charge it weekly during the winter. The flatslides need to be a bit rich on the starting mixture so the bike will fire up when cold. This fat mixture can foul the plugs when the engine is warm and it takes considerable battery effort to start the bike. The fresh battery is essential.
The next post will be about jetting.