authenticnovelty
XS650 Enthusiast
Hi Robert, no resolution on my side to the seal leaks just yet. Sorry I can't be of much help at this point. However, I picked up a timing light this week and learned some important things tonight that may be worth considering as you trouble shoot... I think some of my issues may be related to basic engine timing. With the suggestions of previous posts in this thread to consider the timing advance unit hanging up, I've been thinking about the odd performance variations as timing advance related and not carb mix as I ride and make mental notes.
I checked this week and am pretty sure the advance unit weights not hanging up. Everything seems lubed and strong. However, I notice there is some play in the weights and remember people talking about re-fabricating the ears with JB-weld to build them up and remove the play in some threads. How much play is too much? I need to take a moment and look more closely at the weights again with a timing light. I've attached a video of the slop in the weights to ask opinions:
Now the main event for this post... I've been setting my points gap with a feeler gauge at 0.016" and using my multimeter as a buzz box to set when each point is making contact while rotating the timing plates. Sometimes I have to fight and shift/regap the individual points to get the blocks in the proper location on the cam for the fire marking. The latest points set that I bought came as a set with a condenser on eBay. The quality is a little less than I like (certainly lower quality than the originals on the bike). I've only set static timing previously, as I did not have access to a timing light. Even after setting and getting the meter to match properly, I occasionally have to make a very subtle adjustments on the main plate because timing needs adjusted further... Finally now experimenting with a timing light tonight, and each sparkplug was firing way off! The left cylinder was firing just a hair before TDC and the right cylinder was firing almost 10 degrees after TCD! I can't believe I've been running it like this. I'm pretty sure the multimeter seemed fine when I rechecked them with static method tonight? I still don't know how to explain the shaft seals in the carbs leaking, but this timing discrepancy potentially explains so many other patterns on my bike.
I've now dynamically set the engine timing using the timing light and took it for a test run after. Such a significant difference! It had an immediate power that I've not seen. I also was able to re-adjust the idle screw and set the mixing screw on the carbs down to the 2.25 turn spec. For the real test, we'll have to see how it cold starts in the morning.
A concern that I have with this current timing is that I have turned both timing plates both as far clockwise as they can go, but I still don't think they are firing close enough to the F mark on the stator cover. Is this a matter of a worn cam between the points or are the points possibly deformed? Anything else? I suppose I need to get a degree wheel and mark more accurately on my PMA, but in the mean time I've attached a photo of where I currently have each cylinder set to fire while running with a timing light . Any thoughts? Is there are way I can push it to fire earlier or am I in about the right spot?
Thanks also, 2Many for the link suggestion regarding spigot leak. I think Mailman may have similarly shared the part of it with his choke casting issues previously. After a general skim beyond page 10, that mammoth thread pretty much seems to address anything that can possibly need serviced. I've officially bookmarked it now...
Still always so much more to learn...
I checked this week and am pretty sure the advance unit weights not hanging up. Everything seems lubed and strong. However, I notice there is some play in the weights and remember people talking about re-fabricating the ears with JB-weld to build them up and remove the play in some threads. How much play is too much? I need to take a moment and look more closely at the weights again with a timing light. I've attached a video of the slop in the weights to ask opinions:
Now the main event for this post... I've been setting my points gap with a feeler gauge at 0.016" and using my multimeter as a buzz box to set when each point is making contact while rotating the timing plates. Sometimes I have to fight and shift/regap the individual points to get the blocks in the proper location on the cam for the fire marking. The latest points set that I bought came as a set with a condenser on eBay. The quality is a little less than I like (certainly lower quality than the originals on the bike). I've only set static timing previously, as I did not have access to a timing light. Even after setting and getting the meter to match properly, I occasionally have to make a very subtle adjustments on the main plate because timing needs adjusted further... Finally now experimenting with a timing light tonight, and each sparkplug was firing way off! The left cylinder was firing just a hair before TDC and the right cylinder was firing almost 10 degrees after TCD! I can't believe I've been running it like this. I'm pretty sure the multimeter seemed fine when I rechecked them with static method tonight? I still don't know how to explain the shaft seals in the carbs leaking, but this timing discrepancy potentially explains so many other patterns on my bike.
I've now dynamically set the engine timing using the timing light and took it for a test run after. Such a significant difference! It had an immediate power that I've not seen. I also was able to re-adjust the idle screw and set the mixing screw on the carbs down to the 2.25 turn spec. For the real test, we'll have to see how it cold starts in the morning.
A concern that I have with this current timing is that I have turned both timing plates both as far clockwise as they can go, but I still don't think they are firing close enough to the F mark on the stator cover. Is this a matter of a worn cam between the points or are the points possibly deformed? Anything else? I suppose I need to get a degree wheel and mark more accurately on my PMA, but in the mean time I've attached a photo of where I currently have each cylinder set to fire while running with a timing light . Any thoughts? Is there are way I can push it to fire earlier or am I in about the right spot?
Thanks also, 2Many for the link suggestion regarding spigot leak. I think Mailman may have similarly shared the part of it with his choke casting issues previously. After a general skim beyond page 10, that mammoth thread pretty much seems to address anything that can possibly need serviced. I've officially bookmarked it now...
Still always so much more to learn...