It's a 180. Rule of thumb is 360 is designed to use a single carb and coil. Yours has a single carb, but two coils (pistons alternately firing).
Tires are not so easy. There are as many theories/opinions about them as there are about oil choices. So tire choice is as much trial-and- error as it is research. Generally, the first number of a tire's size is the tread width. Second number is sidewall height (expressed as a percentage of the width, rather than as an actual measurement). So the 100/90 you're seeing is a wider tire by 3/8-1/2 inch and a smidge taller as well. That is, if you can trust a tire manufacturer's measurements. They tend to fudge a bit. Will it work? It'll probably fit, if that's what you mean. Though you may notice some handling differences, depending on how much you've ridden the bike and developed a feel for its personality. A wider front tire will produce a "grippier" feel in turns. Some riders like that, others find it initially unsettling if they're used to the old skinnier-tire handling. There's a tire size discussion on Web Bike World you might find interesting. Bike is a BMW, but the concept is similar enough to be enlightening: http://www.webbikeworld.com/Motorcycle-tires/sizes.htm On Jan 2, 10:39 am, ken browning <[email protected]> wrote: > Just bought a '93 CB 250 and am curious if it's a 360 degree > crankshaft (pistons traveling together) or 180 degree (pistons > alternately firing). Can't seem to find the answer anywhere. Also, > need new tires and the Dunlop on the front is 90/100-18, but all I see > to buy is 100/90-18. Will that work OK? > > Thanks! > > Ken -- You received this message because you are subscribed to the Google Groups "Nighthawk Motorcycle Lovers!" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/nighthawk_lovers?hl=en.
