handlebars
XS650 Member
Hello all,
Let me first start off by saying that this forum has been so very helpful to me so far. In fact it has been so informative that until now, I have gleaned much of the information I needed simply by searching related threads and such, but as winter is here (and I'm not spending all my spare moments tearing up the road
, that it was time to finally join up as a member and stop being such a creeper, haha!
I bought an 83 heritage special in June, after I lost my beloved CB500 in a very fortunate tangle with a gravel truck and trailer. Nope I'm not dead and still have limbs and wits to ride so bought myself a thumper.
Drove all the way down to Portland to buy her. The PO had done quite a few of the things to her that I was planning for a build (lowered front and rear, chopped rear hoop, Left side scrambler open pipes, Pandemonium I think) and a few things I wouldn't have thought of, namely a Joe Wiseguy enforcer 2-1 intake with a single Mikuni VM 36 carb. Despite having the recommended pilly and main jets he couldn't get it running right and gave up. That's where I came in.
I found out by emailing Joe himself that what was missing was the correct needle and needle jet. Once that was sorted out and with some fiddling I got her pretty happy. Nice torquey low throttle transition with no pops or stumbles, very smooth and even power through the range. Was quite impressed. Have never ridden a stocker, but I'm sure the intake carb and exhaust were doing something to pep it up (perhaps a few of you have input on that.)
So the last big ride of this season (about 600 miles) she ran great the whole way, no complaints at all.
That was mid September and the average temp was around 15 degrees Celsius (60 degrees F)
Ok so time to do some more work on it. The charging system was weak (surprise, right?) so I opted for a Hugh's PMA and a Pamco.
I installed the Pamco first, and to make sure all was properly timed, got it running, timed it and took her for a spin. Not so happy. It stumbled quite a bit under a load, and seemed to lack power overall. Although upper throttle seemed ok. Weird I thought. It was so happy with the TCI in there, no issues at all. I double checked the advance was lubed and moving freely and not binding (as per Pete's video), and that it just reached full advance at just over 3000, while being in the fire zone at 1000ish. I checked and stretched the springs a bit, and now the advancer moves smoothly and uniformly without visibly getting hung up anywhere.
I thought perhaps the weak charging system might have had an effect, but it ran fine when it was last ridden a month and a half previous. Nonetheless I moved on and installed the PMA and triple checked the wiring. As best i can tell, the wiring job is solid. The bike has a Sparx capacitor and also in the meantime a brand new Shorai Battery temporarily wired in parallel, so no lack of juice. The PMA is putting out out a solid 14.6volts at idle. (in that regard, I'm quite happy I swapped)
I took the bike for another go and still that annoying stumble/hiss/missing in the early throttle, and in neutral on the stand it stumbles when I crack the throttle too quick. If I roll on slowly, it seems fine. But I can remember that with the TCI it was quite responsive, and would not bog unless I really really tried to make it happen.
I tested the coil (which the PO had replaced just prior to me buying the bike so it's only like 6 months old). I got 2.9ohms across the primary terminals, no shorts anywhere, and 12,700ish Ohms across the plug terminals, where apparently between 15,000 and 20,000 is normal. I borrowed my buddy's coil which read 2.1 across the primaries and 16,200ish. Both coils have been road tested in the bike with no noticible improvement.
Valves were set right before the trip and were right on, cam chain too. I can check them again though, and likely should.
I had iridium plugs in originally, and to check I tried new plugs, though not iridiums, but no dice. They do look a bit on the blacker side, although the electrode tip is not totally fouled, and a tad toward greyer/beige
I cleaned the carb, no improvement, but could do it again, just am really stumped here. It seemed as though this was a case of "this thing runs great" with the TCI, but as soon as I put the Pamco in, then this low end stumble began. I don't really want to put the TCI back in to test, since that will involve going back to the stock alternator and reg/rec, and this Pamco PMA setup really should work right.
I'm wondering if the temperature change (it's colder and damper here in Vancouver now that we are into "winter" (as in the other much longer and wetter season) has made for the carb not being happy set as is. I can't say I'm super great with carb tuning, but it was running fine before... I've heard/read that the VM carbs are less forgiving than the stock carbs in terms of ambient conditions, so perhaps that is the cause, but could the colder and damper air really make enough difference to cause the bike to run like crap?
I should mention also that when cold, the bike starts first hot kick with the choke on (after a couple prime kicks) and once warm will start first kick with the choke off.
There is a bit of dark smoke from the pipes when I crack the throttle. Also, when I run it through the gears up to around 3rd and then pull the clutch in (at the end of my street) the bike idle lowers and almost wants to die, and I have to coax it from stalling.
Whew. That was a lot to write, but I've included as much info as I can think of. It's probably something super simple that I'm missing (hope so anyways) and I'll probably feel dumb once I find the problem, but that's okay by me as long as I find it, haha!
Anyhow, input would be appreciated.
Thanks,
And happy biking!
Jacob
Posted via Mobile
Posted via Mobile
Let me first start off by saying that this forum has been so very helpful to me so far. In fact it has been so informative that until now, I have gleaned much of the information I needed simply by searching related threads and such, but as winter is here (and I'm not spending all my spare moments tearing up the road
, that it was time to finally join up as a member and stop being such a creeper, haha!I bought an 83 heritage special in June, after I lost my beloved CB500 in a very fortunate tangle with a gravel truck and trailer. Nope I'm not dead and still have limbs and wits to ride so bought myself a thumper.
Drove all the way down to Portland to buy her. The PO had done quite a few of the things to her that I was planning for a build (lowered front and rear, chopped rear hoop, Left side scrambler open pipes, Pandemonium I think) and a few things I wouldn't have thought of, namely a Joe Wiseguy enforcer 2-1 intake with a single Mikuni VM 36 carb. Despite having the recommended pilly and main jets he couldn't get it running right and gave up. That's where I came in.
I found out by emailing Joe himself that what was missing was the correct needle and needle jet. Once that was sorted out and with some fiddling I got her pretty happy. Nice torquey low throttle transition with no pops or stumbles, very smooth and even power through the range. Was quite impressed. Have never ridden a stocker, but I'm sure the intake carb and exhaust were doing something to pep it up (perhaps a few of you have input on that.)
So the last big ride of this season (about 600 miles) she ran great the whole way, no complaints at all.
That was mid September and the average temp was around 15 degrees Celsius (60 degrees F)
Ok so time to do some more work on it. The charging system was weak (surprise, right?) so I opted for a Hugh's PMA and a Pamco.
I installed the Pamco first, and to make sure all was properly timed, got it running, timed it and took her for a spin. Not so happy. It stumbled quite a bit under a load, and seemed to lack power overall. Although upper throttle seemed ok. Weird I thought. It was so happy with the TCI in there, no issues at all. I double checked the advance was lubed and moving freely and not binding (as per Pete's video), and that it just reached full advance at just over 3000, while being in the fire zone at 1000ish. I checked and stretched the springs a bit, and now the advancer moves smoothly and uniformly without visibly getting hung up anywhere.
I thought perhaps the weak charging system might have had an effect, but it ran fine when it was last ridden a month and a half previous. Nonetheless I moved on and installed the PMA and triple checked the wiring. As best i can tell, the wiring job is solid. The bike has a Sparx capacitor and also in the meantime a brand new Shorai Battery temporarily wired in parallel, so no lack of juice. The PMA is putting out out a solid 14.6volts at idle. (in that regard, I'm quite happy I swapped)
I took the bike for another go and still that annoying stumble/hiss/missing in the early throttle, and in neutral on the stand it stumbles when I crack the throttle too quick. If I roll on slowly, it seems fine. But I can remember that with the TCI it was quite responsive, and would not bog unless I really really tried to make it happen.
I tested the coil (which the PO had replaced just prior to me buying the bike so it's only like 6 months old). I got 2.9ohms across the primary terminals, no shorts anywhere, and 12,700ish Ohms across the plug terminals, where apparently between 15,000 and 20,000 is normal. I borrowed my buddy's coil which read 2.1 across the primaries and 16,200ish. Both coils have been road tested in the bike with no noticible improvement.
Valves were set right before the trip and were right on, cam chain too. I can check them again though, and likely should.
I had iridium plugs in originally, and to check I tried new plugs, though not iridiums, but no dice. They do look a bit on the blacker side, although the electrode tip is not totally fouled, and a tad toward greyer/beige
I cleaned the carb, no improvement, but could do it again, just am really stumped here. It seemed as though this was a case of "this thing runs great" with the TCI, but as soon as I put the Pamco in, then this low end stumble began. I don't really want to put the TCI back in to test, since that will involve going back to the stock alternator and reg/rec, and this Pamco PMA setup really should work right.
I'm wondering if the temperature change (it's colder and damper here in Vancouver now that we are into "winter" (as in the other much longer and wetter season) has made for the carb not being happy set as is. I can't say I'm super great with carb tuning, but it was running fine before... I've heard/read that the VM carbs are less forgiving than the stock carbs in terms of ambient conditions, so perhaps that is the cause, but could the colder and damper air really make enough difference to cause the bike to run like crap?
I should mention also that when cold, the bike starts first hot kick with the choke on (after a couple prime kicks) and once warm will start first kick with the choke off.
There is a bit of dark smoke from the pipes when I crack the throttle. Also, when I run it through the gears up to around 3rd and then pull the clutch in (at the end of my street) the bike idle lowers and almost wants to die, and I have to coax it from stalling.
Whew. That was a lot to write, but I've included as much info as I can think of. It's probably something super simple that I'm missing (hope so anyways) and I'll probably feel dumb once I find the problem, but that's okay by me as long as I find it, haha!
Anyhow, input would be appreciated.
Thanks,
And happy biking!
Jacob
Posted via Mobile
Posted via Mobile
