KJ790
XS650 Enthusiast
- Messages
- 39
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- 6
Today I ran into an interesting problem. My '81 XS650 had not been charging the battery and I discovered that the rotor was bad. The bike sat in my garage for about 5 weeks while I waited for time to fix it. I bought a new rotor and put it in yesterday and everything seemed to be good. I took it for a quick spin today and everything seemed fine, rode about 10 miles, revved through the RPM range fine. Stopped at home for about 15 minutes, then went to leave again and as soon as I pulled onto the road and gave it any sort of gas it just started to break down and would not rev up at all.
It will idle perfect, but as soon as you touch the throttle it starts to sound like crap and will not rev past 2,000 RPM. I drained the gas out of the tank and carbs and put in fresh gas, no difference. I checked the cam timing, no difference. I pulled out each spark plug one at a time and ran it and it did the same thing on each cylinder.
Any ideas what it could be? Since both cylinders are affected, I find it hard to believe that it could be a carburetor issue (though it's not impossible). I will pull the carbs out when I get time and clean them out, but I doubt that is the problem. It seems to me like it is an ignition problem. Only bike I've ever had act like this was a newer bike with a CDI ignition and the CDI went bad. I don't really know where to start first with this one, any help would be great.
It will idle perfect, but as soon as you touch the throttle it starts to sound like crap and will not rev past 2,000 RPM. I drained the gas out of the tank and carbs and put in fresh gas, no difference. I checked the cam timing, no difference. I pulled out each spark plug one at a time and ran it and it did the same thing on each cylinder.
Any ideas what it could be? Since both cylinders are affected, I find it hard to believe that it could be a carburetor issue (though it's not impossible). I will pull the carbs out when I get time and clean them out, but I doubt that is the problem. It seems to me like it is an ignition problem. Only bike I've ever had act like this was a newer bike with a CDI ignition and the CDI went bad. I don't really know where to start first with this one, any help would be great.