hard_y_rd
XS650 Guru
You should be getting a good fat spArk. I would look into your coil setup. I run a single capacitor with no battery. When I kick it over the spark is good. Make sure the headlight is off though.
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Issues with first start. Pamco, PMA, Rephase, Fresh build.
- Thread starter WhenInXS
- Start date
Yea im getting really good spark now. I think it's all in the carbs now. Major bummer is, I just took my throttle shafts apart and buggered up one of the threaded holes on the shaft. Talk about a hard to find part! Found a set of bs38's on ebay but he messaged me back and said his butterfly is labeled 120 where as mine is labeled 115. They seem to be about the same year carbs as what I have, seeing as they arnt linked and I think they only did that in 75-76. This is a major bummer -__- anyone know if that throttle shaft will work? Just put my 115 in instead of the 120?
still not running, have fuel and spark. just finished cleaning/rebuilding the carbs again new everything in there. and now nothing! Still sparking and getting fuel, left carb slide is still falling pretty fast compared to the right side. brand new diaphragms and i checked the choke setup and everything looked to be good there. running out of patience haha.
pamcopete
Ride.Enjoy.Life is Simple
WhenInXS,
Try the battery again with the PMA disconnected.
Try the battery again with the PMA disconnected.
Hey, WhenInXS. Sounds like these carbs are challenging your wits. Here's a few thoughts.
The 'pumping' you were doing doesn't pump fuel, there's no acceleration pump. It does, however, momentarily allow excess fuel vapors in the manifold to evaporate out. So, that tells me that your idle mix is rich.
The 'linked' carbs started in '76. The idle mix setting for the '75 carbs is like 3/4 turn out.
The 'falling' slide/diaphragm on the left side could be an indication of a faulty enrichener valve. The bottom, atmospheric chamber side of the diaphragm is also the source for intermix 'bleed' air for the enrichener. Be sure to turn 'off' the 'choke' before doing the slide drop test. Study this pic.
Need to positively ID your carbs before jetting and such makes sense...
The 'pumping' you were doing doesn't pump fuel, there's no acceleration pump. It does, however, momentarily allow excess fuel vapors in the manifold to evaporate out. So, that tells me that your idle mix is rich.
The 'linked' carbs started in '76. The idle mix setting for the '75 carbs is like 3/4 turn out.
The 'falling' slide/diaphragm on the left side could be an indication of a faulty enrichener valve. The bottom, atmospheric chamber side of the diaphragm is also the source for intermix 'bleed' air for the enrichener. Be sure to turn 'off' the 'choke' before doing the slide drop test. Study this pic.
Need to positively ID your carbs before jetting and such makes sense...
Yea, I noticed that with the choke. I meant to mention that was with the choke off. It's slower than just dropping it but still only about a 5sec. Drop. I took the choke stuff apart and noticed no signs of where on the little rubber stopper or anything. But yes my idle circuit seems a little rich which is kind of strange. Because I have exhaust uni filters and stock pilot. Mix screw 3/4 turn out. My carbs are the 74-75 as it has the 4n8-4 needle.
What would be an indicator of that choke piece being worn. I could hardly find clear images of good ones on the web.
What would be an indicator of that choke piece being worn. I could hardly find clear images of good ones on the web.
Well, it's just a valve. I suppose you could cobble-up a piece of tubing that you blow/suck thru to test the on/off sealing of its ports...
Alright, so bikes still not running. I've just gotten back from a vacation (were of course couldn't think about anything but the bike) and I have 4 days until I have to return to work. Trying to get things sorted.
As of now the bike will start run for about 5 seconds (sounds great) and then die. Not like a run out of fuel die but more of a something really wrong die. It seems like it's firing while the piston is still trying to come up in the compression stroke causing a sudden and complete stop. However all the timing is from what I can tell spot on. Plugs are firing great coils ohm out perfectly compression in cylinders is good. Another strange thing is after it starts and runs for those 5 or so seconds the next kick is basically impossible (you can stand on the damn kicker.) Unless I Crack the throttle, then it just kicks threw like normal. It almost seems like it's some type of vapor lock happening in the cylinders givin the abbrutnesz that the motor comes to a halt. (I really don't know how to explain that...) I've built countless motors but this little guy is making me feel like a complete idiot haha. I'm kinda wanting to eliminate one cylinder via the dead cylinder method and see if it'll just run on one cylinder but can't find much info on if that's alright to do with a rephased motor. I don't see why it wouldn't be.
As of now the bike will start run for about 5 seconds (sounds great) and then die. Not like a run out of fuel die but more of a something really wrong die. It seems like it's firing while the piston is still trying to come up in the compression stroke causing a sudden and complete stop. However all the timing is from what I can tell spot on. Plugs are firing great coils ohm out perfectly compression in cylinders is good. Another strange thing is after it starts and runs for those 5 or so seconds the next kick is basically impossible (you can stand on the damn kicker.) Unless I Crack the throttle, then it just kicks threw like normal. It almost seems like it's some type of vapor lock happening in the cylinders givin the abbrutnesz that the motor comes to a halt. (I really don't know how to explain that...) I've built countless motors but this little guy is making me feel like a complete idiot haha. I'm kinda wanting to eliminate one cylinder via the dead cylinder method and see if it'll just run on one cylinder but can't find much info on if that's alright to do with a rephased motor. I don't see why it wouldn't be.
Could try to remove the plugs, and kick it thru a few times, listening/feeling for anything mechanically wrong.
Also check for excessive sloppiness in the ignition advance contraption. Engine jostlations could cause momentary over-advance...
Also check for excessive sloppiness in the ignition advance contraption. Engine jostlations could cause momentary over-advance...
Alright, then reinstall plugs, try kickstarting again, but this time: Fuel off, choke off, full throttle, ign on.
Then, after a few kick attempts: Fuel on, choke off, no throttle, ign on.
Then, after those few attempts: Fuel on, choke on, no throttle, ign on.
Post up if anything is different...
Then, after a few kick attempts: Fuel on, choke off, no throttle, ign on.
Then, after those few attempts: Fuel on, choke on, no throttle, ign on.
Post up if anything is different...
Ok.
That's Bill. He's done with us.
Nap time for me...
That's Bill. He's done with us.
Nap time for me...
I was having the same issue after a fresh rebuild. I added the e-advance with the new magnet onto my old pamco and couldn't get it to run based on pamco's instructions. What fixed mine was removing both screws from the ignition mounting plate and spinning it around until it would fire right. after that i had to grind off part of that plate since it spun so far around that the mounting holes were covered.
^see that's what I'm figuring I'm going to have to end up doing.. because to me it seems like it's firing way advanced, causing the sudden abrupt stop of the engine. (Firing against the Pistons stroke.) I just don't want to do anything that dramatic until I know it's going to fix an issue.
Haven't fitted one of these yet but I read Hugh's article several months ago before I bought the pamco and looking at your pictures it looks like your rotor isn't aligned properly. The magnets aren't level with each other and horizontal across the top quadrant of the rotor. I remembered Hugh's image showing them level, just looked again and they are level, kind of at 11 o'clock and 1 o'clock.
Was your picture definitely taken at tdc?
Was your picture definitely taken at tdc?
pamcopete
Ride.Enjoy.Life is Simple
Having to move the plate out of it's normal adjustment range could be an indication of something else wrong, especially in a recently rebuilt engine, the cam chain comes to mind.
However, if you need more adjustment room, you can loosen the rotor and hold it in the opposite direction of what you need and then tighten the nut while holding the rotor in position. IE: If you need more advance, hold the rotor in the counterclockwise position. If you need more retard, hold the rotor in the clockwise position while tightening the nut.
However, if you need more adjustment room, you can loosen the rotor and hold it in the opposite direction of what you need and then tighten the nut while holding the rotor in position. IE: If you need more advance, hold the rotor in the counterclockwise position. If you need more retard, hold the rotor in the clockwise position while tightening the nut.
Tlcbobber the first pick is showing the tdc he shows its pretty straight (kind of a strange angle) but it is on the lower plane compared to how his picture shows to be on the upper plane. However in his write up he says this doesn't matter just as long as there horizontal. I've been trying to figure that out myself you would think it would still fire wrong... I get that the cam turns twice per revolution of the crank but it'd still be firing on the wrong stroke... anyway I am debating pulling my valve cover and putting the cam one more tooth back witch may solve why the 2 magnets are just a hair off.
