Technical Q and A for classic motorcycle maintenance and repair.
Editor’s note: If you’re having trouble with that old Suzuki, BSA or BMW, Keith Fellenstein is your guy. From motorcycle tuning tips to detailed motorcycle engine repair, he can draw from a wealth of experience to help guide you to success. Send questions to: Keith’s Garage, Motorcycle Classics, 1503 SW 42nd St., Topeka, KS 66609, or send an e-mail with “Keith’s Garage” as the subject.
Hard-starting Yamaha SR500
Q: I’ve owned my early 1980s Yamaha SR500 since new and it has always been hard to get started when cold. Unless I get the kickstarter at the very top of its stroke by using the compression release and give it all the oomph I’ve got, it doesn’t even think about starting. Even then, if I’m holding my mouth wrong it won’t start and I have to try again, over and over. If I’m parked on any kind of a slope it’s much easier to just get it rolling and bump start it. Hot starts are a little more predictable. I’ll press that little white button up on the bottom of the carburetor (which cracks the throttle open a bit) and if I’m lucky it will start after a couple or so kicks. Is this a normal situation for these old thumpers, or did I just get a lemon from the get-go? Is it an ignition thing, timing, a mixture issue or what? It’s never kicked back on me. The bike runs fine once it’s started, and I really enjoy riding the SR500. In fact I’d probably ride it a lot more if it wasn’t such a recalcitrant B#$%@ to start. Do you have any ideas how I can get the old girl to start more easily on a more regular basis? — Mac/via email
A: I have a friend with an SR500 who is making a custom out of it. He will soon be bringing it to me to do the wiring and I’m looking forward to the chance to learn more about the model. Your mention of hot starts being easier makes me suspect you could go a little richer on the idle jet to improve your cold starts. What does your spark plug look like? White insulator or brown to black? If mostly white it’s definitely lean, a common condition with bikes of that era. MC