[vintagebikes]

Hello,

I’m new to this forum and I’m looking forward to getting involved in it. I’m having trouble with my bike. It’s a 1980 Suzuki sp400. The bike lacks in power, idles poorly and it backfires during deceleration. I’ve tried adjusting the valves and timing with little or no improvements. The bike has good compression. I’ve been told it could be: intake problem, CDI or improperly adjusted timing. Other than moving the timing chain I don’t believe there is a way to adjust the timing, but I’m just starting to work on bikes and I really have no idea. I have a factory service manual (I’d be happy to email to anyone who needs it) and I’ve been through the troubleshooting section several times and I just don’t know what to do. All advice is welcome, thanks.