xHolepunchx
XS650 Enthusiast
Last night I had my 1980 xs650 on the highway going about 70 for about 20 minutes. It started making somewhat of a strained noise, on the right side, kinda like a scratchy squeal and the piston hits were becoming more audible even over the highway noise.
I tried to make it to an exit to check some things, but before I could make it that far the bike briefly lost power and bogged. I went from 70 to 45 and couldn't get the throttle to respond with anything more than a feeble pull from the engine. I pulled off to the side, and shut off the bike for a few minutes.
I started it back up and it seemed like it ran fine after a brief cool down but the idle was about 2000 opposed to the 1100-1200 it usually runs warm. I hopped back on the interstate and it was good for a couple min, and then by the next exit was still making a bit more noise out of the right cylinder, so I pulled into a gas station.
Recently the bike had been making a light popping in the exhaust until warmed up on de-acceleration, so I thought maybe that cylinder was running lean and causing an overheat issue. I re-set the mix on the right side to a slightly richer setting and checked the plugs (both looked fine) and started her back up. Running at idle, no unusual noises. Revving in neutral, no unusual noises.
So, now off the highway, I rode it around the gas station parking lot and could hear the noise a lot clearer, it sounded like a hard knock coming from the top of the right piston, but only when moving in gear and when pulling on the throttle. I had to drive it a few more miles and as I drove it i went very easy on it. Even at low throttle it doesn't make the noise all the time, but at takeoffs and acceleration it would become very audible. If i pull the clutch and roll it stops, if I let off the throttle and let the bike coast with the clutch engaged, it makes no added noise (even at higher rpms, in lower gears).
It will also make the noise if while moving in gear I pull the clutch and then roll the throttle, but wont when the bike is in neutral just sitting still and I rev. This is not leaving me with a very definable situation to look into, any old pros ever run into anything like this. I have the biked garaged till I can figure it out out of fear of blowing the engine even though she seems to run just fine aside from this noise. Any help troubleshooting is most appreciated, and I thank you in advance.
I tried to make it to an exit to check some things, but before I could make it that far the bike briefly lost power and bogged. I went from 70 to 45 and couldn't get the throttle to respond with anything more than a feeble pull from the engine. I pulled off to the side, and shut off the bike for a few minutes.
I started it back up and it seemed like it ran fine after a brief cool down but the idle was about 2000 opposed to the 1100-1200 it usually runs warm. I hopped back on the interstate and it was good for a couple min, and then by the next exit was still making a bit more noise out of the right cylinder, so I pulled into a gas station.
Recently the bike had been making a light popping in the exhaust until warmed up on de-acceleration, so I thought maybe that cylinder was running lean and causing an overheat issue. I re-set the mix on the right side to a slightly richer setting and checked the plugs (both looked fine) and started her back up. Running at idle, no unusual noises. Revving in neutral, no unusual noises.
So, now off the highway, I rode it around the gas station parking lot and could hear the noise a lot clearer, it sounded like a hard knock coming from the top of the right piston, but only when moving in gear and when pulling on the throttle. I had to drive it a few more miles and as I drove it i went very easy on it. Even at low throttle it doesn't make the noise all the time, but at takeoffs and acceleration it would become very audible. If i pull the clutch and roll it stops, if I let off the throttle and let the bike coast with the clutch engaged, it makes no added noise (even at higher rpms, in lower gears).
It will also make the noise if while moving in gear I pull the clutch and then roll the throttle, but wont when the bike is in neutral just sitting still and I rev. This is not leaving me with a very definable situation to look into, any old pros ever run into anything like this. I have the biked garaged till I can figure it out out of fear of blowing the engine even though she seems to run just fine aside from this noise. Any help troubleshooting is most appreciated, and I thank you in advance.