- Joined
- Aug 23, 2017
- Messages
- 269
Hi folks,
I've run into a problem that I'm hoping someone might be able to help me with. I've got my 72 roadster (non-combat) running and have gone for a few test rides and everything seemed be working pretty good. Then one day last week I went to go for a ride and I stalled as I was pulling out of the shed. I thought that I had just not opened the throttle enough, so I started her again, and managed to going, but she was hating every incline and was threatening to cut out. And a few times she did cut out. I would put her on the centre stand and give her a kick, and she would start and run fine, but I started to notice that she was running differently on and off the centre stand. On the stand things are fine, but when I take her off she may or may not continue to idle, and will cut out with any throttle pretty much every time - especially going up a hill. And that's been the case pretty much ever since.
I've got a single Mikuni carb, that was in bad shape when I got the bike first (very dirty with blocked jets etc), but that was working fine earlier this season, and a Boyer MKIII ignition.
I've tried a few things so far, but nothing has solved it. First I made minor adjustments to the timing, and that seemed to help a bit. I was a little on the retarded side, just trying to avoid kickback, so I advanced it a little, and she sounds beautiful now... on the stand. I figure it's likely a carb related thing, so I pulled that off and cleaned everything, and blew all the jets out. I did this three times, and she is starting first kick every time when warm, and running beautifully on the stand. I can rev her up to whatever RPM I want and she seems to run perfectly on the stand. But if I take her off the stand she might idle, or she might cut right out immediately. Or she will cut out if I give her some throttle. Gentle throttle and out she goes. A quick blast, and she dies as I release it.
I figured maybe the fuel level in the float bowl would make a difference so I adjusted that a number of times. First I tried more fuel in the bowl. That resulted in immediate cut out off the stand, so I decreased the level of fuel, at one point not have any fuel in the bowl at all. Having the minimum fuel level seemed to help a bit, and I thought I was going to have it solved with these adjustments, but with the lowest amount of fuel in the bowl that will still let her run, it will sometimes idle decently off the stand but other times will die almost right away, and will pretty much always die if I throttle up at all when she is off the stand. But on the stand she runs like a champ! I've tried every air and throttle screw combination that I can think of and sometimes I think I'm on to something, and she'll die again off the stand.
A couple of possible clues are the fact that the engine is running rich (soot on the plugs), and that the weather has been warmer since this issue developed. I have no idea if cool weather would cure it, but its a good 10 degrees Celsius warmer than when I was able to drive around.
Anyway, I'm having trouble thinking of what to try next. Any ideas? Thanks!
I've run into a problem that I'm hoping someone might be able to help me with. I've got my 72 roadster (non-combat) running and have gone for a few test rides and everything seemed be working pretty good. Then one day last week I went to go for a ride and I stalled as I was pulling out of the shed. I thought that I had just not opened the throttle enough, so I started her again, and managed to going, but she was hating every incline and was threatening to cut out. And a few times she did cut out. I would put her on the centre stand and give her a kick, and she would start and run fine, but I started to notice that she was running differently on and off the centre stand. On the stand things are fine, but when I take her off she may or may not continue to idle, and will cut out with any throttle pretty much every time - especially going up a hill. And that's been the case pretty much ever since.
I've got a single Mikuni carb, that was in bad shape when I got the bike first (very dirty with blocked jets etc), but that was working fine earlier this season, and a Boyer MKIII ignition.
I've tried a few things so far, but nothing has solved it. First I made minor adjustments to the timing, and that seemed to help a bit. I was a little on the retarded side, just trying to avoid kickback, so I advanced it a little, and she sounds beautiful now... on the stand. I figure it's likely a carb related thing, so I pulled that off and cleaned everything, and blew all the jets out. I did this three times, and she is starting first kick every time when warm, and running beautifully on the stand. I can rev her up to whatever RPM I want and she seems to run perfectly on the stand. But if I take her off the stand she might idle, or she might cut right out immediately. Or she will cut out if I give her some throttle. Gentle throttle and out she goes. A quick blast, and she dies as I release it.
I figured maybe the fuel level in the float bowl would make a difference so I adjusted that a number of times. First I tried more fuel in the bowl. That resulted in immediate cut out off the stand, so I decreased the level of fuel, at one point not have any fuel in the bowl at all. Having the minimum fuel level seemed to help a bit, and I thought I was going to have it solved with these adjustments, but with the lowest amount of fuel in the bowl that will still let her run, it will sometimes idle decently off the stand but other times will die almost right away, and will pretty much always die if I throttle up at all when she is off the stand. But on the stand she runs like a champ! I've tried every air and throttle screw combination that I can think of and sometimes I think I'm on to something, and she'll die again off the stand.
A couple of possible clues are the fact that the engine is running rich (soot on the plugs), and that the weather has been warmer since this issue developed. I have no idea if cool weather would cure it, but its a good 10 degrees Celsius warmer than when I was able to drive around.
Anyway, I'm having trouble thinking of what to try next. Any ideas? Thanks!