Problem solved, turning the air screws a half turn made a tremendous difference. Hot or cold, under load or at idle, the bike had awesome throttle response and great pull.
At this point all that remains is some fine tuning, as under hard load from around 3,000 rpm to 4,000 rpm the Suzuki falls on it’s face, but quickly recovers. Some of our old-timer mechanic friends chimed in and they believed this might be an issue we have to live with as our Suzuki has one of the first electronic ignition. It's hard to dial in this ignition as that's the point the timing advances. We may try to re-jet the bike and play with timing to get it perfect, but for now, we’re satisfied.
We still had electrical issues as the headlight would cut out occasionally and the turn signals don’t work. Those issues will fix themselves as we plan on rewiring the bike anyway. Now that the bike was running great, braked and steered properly, we're able to start the fun part – tear down.
We also did a compression test using an auto-parts rental tool to make sure we had good compression on all four cylinders. It's tight!
Tear Down We took our time, took notes and had plenty of boxes, sandwich bags and markers. Luckily, the main harness and front harness are plugged into each other with specific plugs that you can’t mess up when reinstalling. For the rest of the pieces we traced wires back to their origins, taking video notes on phones and leaving marked tape on wires.
The engine required the removal of six mounting plates and a couple bolts. We laid the entire bike over onto our Craftsman bike stand and then lifted the frame out from around the engine. Now, we’ve begun prepping the frame for paint, removing any unnecessary brackets and cleaning up sloppy factory welds.
The engine will receive spray-bomb, high-temp engine paint, but needs a heavy cleaning. We covered the intake and exhaust ports and scrubbed the engine with Home Depot pipe-cleaner wire brushes and Purple Power cleaner. We used our Harbor Freight grinding wheel with a cheap wire brush to tackle any area it would reach. We found some smaller brass brushes designed to work with electric screw drivers at the swap meet that we will also use before painting. The better the prep, the better the final paint.
Next Installment We picked up a new front end off of a Suzuki RM250 with inverted forks for cheap off of Craigslist. We also found a mono-shock swing arm from a dirt bike along with a Triumph seat and a CB750 tank that needs restoration. In our next installment we’ll show how to restore a gas tank and properly space a swing arm. The new pieces are an odd-ball combination, but we have a few ideas in mind that will make for a cool bike.