Hello,
I have recently renovated an xs650 a 1974 and have what I believe to be carb problems, the bike has a new Boyer ignition and has been set up as per the instructions. The carbs are standard for the bike and were stripped and cleaned, with all passages checked, the bike is fitted with standard filter boxes, however the mesh is now wrapped with 10mm filter foam, silencers are pretty standard and from xs650 in Germany.
On initial start up the bike ran, but not very well throughout its range, I completed about 60 miles on it, but it was running very rich, with sooty plugs. I fitted keyster carb kits with standard jets for this model and Road tested again for 60 miles. It ran ok and the plugs were pretty good, (see photo), however did not run as good as my previous xs650b.
Still difficult to start. Choke seems to help but starts best on a closed throttle and then coaxed into life with throttle.
Idled on one cylinder until warm (no2)
Cylinder no 1 fumbles when you open the individual carb and pops back on closed throttle at very low revs
When you open the throttle and both cylinders kick in it accelerates strongly, however runs out of power at about 65mph, not missing
but just creeps up slowly from there. I have tried different mixture settings but start from the 3/4 of a turn recommended setting, balanced the carbs and adjusted tick over settings many times.
Any one got any advice on what my course of action should be, do I need to change jet sizes, especially pilots or play around with timing
I have recently renovated an xs650 a 1974 and have what I believe to be carb problems, the bike has a new Boyer ignition and has been set up as per the instructions. The carbs are standard for the bike and were stripped and cleaned, with all passages checked, the bike is fitted with standard filter boxes, however the mesh is now wrapped with 10mm filter foam, silencers are pretty standard and from xs650 in Germany.
On initial start up the bike ran, but not very well throughout its range, I completed about 60 miles on it, but it was running very rich, with sooty plugs. I fitted keyster carb kits with standard jets for this model and Road tested again for 60 miles. It ran ok and the plugs were pretty good, (see photo), however did not run as good as my previous xs650b.
Still difficult to start. Choke seems to help but starts best on a closed throttle and then coaxed into life with throttle.
Idled on one cylinder until warm (no2)
Cylinder no 1 fumbles when you open the individual carb and pops back on closed throttle at very low revs
When you open the throttle and both cylinders kick in it accelerates strongly, however runs out of power at about 65mph, not missing
but just creeps up slowly from there. I have tried different mixture settings but start from the 3/4 of a turn recommended setting, balanced the carbs and adjusted tick over settings many times.
Any one got any advice on what my course of action should be, do I need to change jet sizes, especially pilots or play around with timing
I can cast al and cu alloys out back the shop, but cores and patterns are what take all the work...
