Yup - with several bodies displaying the same little pimpley mark, it is almost certain that is a gate or maybe something left over from the machining operations on the raw castings.
Pete
Pete
-
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On the road again at 40.............the bike that is
I think Pete is right about the casting in general. But from some (rather limited) bronze casting, I think you are looking at the little vents, or gates for air to escape during casting. The air, (or wax in the case of bronze casting) in a mold needs to vent out as the molten metal replaces it.
Regardless, it seems everyone is right on with the solution; file/polish the casting or get a thicker, better fitting gasket.
Regardless, it seems everyone is right on with the solution; file/polish the casting or get a thicker, better fitting gasket.
Agreed EE - it could be a vent.
The other day when I was testing things, my wife was taking her new baby out to do her business. A 9 week old Golden Retriever puppy. She came by the shop as my Black 78 was running testing my carbs and she said, “Boy does that ever sound good, and have you ever cleaned it up nice”. Guess she got tired of listening to the other one too.
I was getting tempted to do the M/C and brakes one afternoon, swap on the blue tank and side covers, put the plate on it, and ride her. LEO wouldn't check the VIN would he?
Installed, gapped new points. Set timing with test light, then timing light. Definite improvement, which makes sense. Points were pretty badly cratered in the centre. Thanks again 5twins! But once warmed up, a slight stumble and missing again, not as bad as before though, although it did keep wanting to stall.
Still haven't got it to run well enough to fine tune mix screws/sync but Carbs run great on the 78, so I can't see how this can still be a carb issue. It is running a little rich still.
Tried 5twins propane test. Once warmed up, no manifold or other leaks. Propane in carb inlets, right carb speeds up, left carb slows down.
Weak spark maybe?
So thought might as well change the condenser while I'm at it. Maybe a slight improvement, hard to tell. Swapping condenser leads had no effect.
Pulled the plugs, left was wet with fuel, right looked rich, but they just been cleaned earlier that day. Left side shutting down for some reason. Put in a new plug and it ran, both sides, but still wants to stall.
Checked cam chain tensioner while it was warmed up.
Did all the coil tests again and everything was within specs when cold, thought I'd try again when it warms up and see if they're breaking down with heat.
So sat a spell in the thinkin’/cryin' chair and pondered.
Now I'm not a great motorcycle diagnostician/troubleshooter/tuner, and certainly not the quickest, but by process of elimination, and with all your guys help I was thinking……….
“Okay, we're a lot closer, let's do a full tune up tomorrow, and if need be, test the coils warmed up”.
Time to walk away for the day.
Next Day
Start at square one and do a tune up.
Cam chain tensioner was good yesterday.
Set Valves Intake .002” Exhaust.006”
Set points: Dwell spec 88° to 98°, got these to 92° - 23° on 4 cylinder setting on YM dwell meter.
Timing set with timing light retarded to right line of |F|. Getting some bounce past at full advance on both sides so I guess that indicates my advance is worn. Would new springs/tightening the springs solve this?
Fired up one kick.
Started fine tuning carbs mix screws. Now I HAVE to build that manometer. Smoothed out nicely. Good enough to ride. Pulled the test tank, popped on the gas tank, didn't worry about the air boxes for a few trips around the block.
Here she is when we got home.
So Bob, please send me an application package for the ‘Cautiously Optimistic’ Club.
Still have to play with mix screws a little and sync carbs.
It's idling a little high, seems to like it there, not as smooth at 1100-1200.
Haven't retested the coils when warm, may not need to?
I recall reading where 5twins said that if your timing is retarded that far you might have to compensate by turning the idle up a bit. We'll see if fine tuning the carbs a little more helps, or if that's just the way it is.
Heading out to celebrate with a weekend of music in the park at London's 'Home County Folk Festival’, that's been running since 1973.
Oh ya, and Daddy wants a Pamco and E-advance for Christmas.
I was getting tempted to do the M/C and brakes one afternoon, swap on the blue tank and side covers, put the plate on it, and ride her. LEO wouldn't check the VIN would he?
Installed, gapped new points. Set timing with test light, then timing light. Definite improvement, which makes sense. Points were pretty badly cratered in the centre. Thanks again 5twins! But once warmed up, a slight stumble and missing again, not as bad as before though, although it did keep wanting to stall.
Still haven't got it to run well enough to fine tune mix screws/sync but Carbs run great on the 78, so I can't see how this can still be a carb issue. It is running a little rich still.
Tried 5twins propane test. Once warmed up, no manifold or other leaks. Propane in carb inlets, right carb speeds up, left carb slows down.
Weak spark maybe?
So thought might as well change the condenser while I'm at it. Maybe a slight improvement, hard to tell. Swapping condenser leads had no effect.
Pulled the plugs, left was wet with fuel, right looked rich, but they just been cleaned earlier that day. Left side shutting down for some reason. Put in a new plug and it ran, both sides, but still wants to stall.
Checked cam chain tensioner while it was warmed up.
Did all the coil tests again and everything was within specs when cold, thought I'd try again when it warms up and see if they're breaking down with heat.
So sat a spell in the thinkin’/cryin' chair and pondered.
Now I'm not a great motorcycle diagnostician/troubleshooter/tuner, and certainly not the quickest, but by process of elimination, and with all your guys help I was thinking……….
“Okay, we're a lot closer, let's do a full tune up tomorrow, and if need be, test the coils warmed up”.
Time to walk away for the day.
Next Day
Start at square one and do a tune up.
Cam chain tensioner was good yesterday.
Set Valves Intake .002” Exhaust.006”
Set points: Dwell spec 88° to 98°, got these to 92° - 23° on 4 cylinder setting on YM dwell meter.
Timing set with timing light retarded to right line of |F|. Getting some bounce past at full advance on both sides so I guess that indicates my advance is worn. Would new springs/tightening the springs solve this?
Fired up one kick.
Started fine tuning carbs mix screws. Now I HAVE to build that manometer. Smoothed out nicely. Good enough to ride. Pulled the test tank, popped on the gas tank, didn't worry about the air boxes for a few trips around the block.
Here she is when we got home.
So Bob, please send me an application package for the ‘Cautiously Optimistic’ Club.
Still have to play with mix screws a little and sync carbs.
It's idling a little high, seems to like it there, not as smooth at 1100-1200.
Haven't retested the coils when warm, may not need to?
I recall reading where 5twins said that if your timing is retarded that far you might have to compensate by turning the idle up a bit. We'll see if fine tuning the carbs a little more helps, or if that's just the way it is.
Heading out to celebrate with a weekend of music in the park at London's 'Home County Folk Festival’, that's been running since 1973.
Oh ya, and Daddy wants a Pamco and E-advance for Christmas.
All right Robin! That bike sounds great man! You're really getting it dialed in. Your hard work is really paying off!
Your application to the " Cautiously Optimistic Club" is in the mail. Haha
Now enjoy your weekend, have fun at the festival!
Your application to the " Cautiously Optimistic Club" is in the mail. Haha
Now enjoy your weekend, have fun at the festival!
Thanks Bob! Pretty juiced, wanna ride, but this weekend is my annual summer holiday.
Lots of summer left yet!
Lots of summer left yet!
Sounds excellent Robin - well done!
Hey, robinc. Sounds like you're right on about the "rich" condition.
While it's idling:
Push down on the choke plungers, note any change.
Cover the half-mood diaphragm vent port, note any change.
Take a piece of small tubing, blow thru it while aiming the exit end at the pilot air bleed port. Note any changes.
Pat yer head and rub yer belly while spinning counterclockwise. Note any dizziness...
While it's idling:
Push down on the choke plungers, note any change.
Cover the half-mood diaphragm vent port, note any change.
Take a piece of small tubing, blow thru it while aiming the exit end at the pilot air bleed port. Note any changes.
Pat yer head and rub yer belly while spinning counterclockwise. Note any dizziness...
Thanks Pete.
Nother cool story from today:
Buddy was over hanging out and helping again today. This is the buddy who found a $100, 1980 barn find last fall. PO said it was seized. Not anymore, we had it running, but needs a lot of work.
Helped him with the carbs awhile back and he still hasn't gotten around to mounting them yet.
After I got home from a few laps, asked him where his helmet was. “Always in the truck”. Well ya better go get it.
I was really curious as to his reaction. His last bike was a 'busa’.
Huh, he was gone a lot longer than me.
Well……..
“Man I love it, didn't think I would so much, these bikes are great, when can we get mine going again?”
Guess Black Betty's going to have to wait a little bit longer.
Nother cool story from today:
Buddy was over hanging out and helping again today. This is the buddy who found a $100, 1980 barn find last fall. PO said it was seized. Not anymore, we had it running, but needs a lot of work.
Helped him with the carbs awhile back and he still hasn't gotten around to mounting them yet.
After I got home from a few laps, asked him where his helmet was. “Always in the truck”. Well ya better go get it.
I was really curious as to his reaction. His last bike was a 'busa’.
Huh, he was gone a lot longer than me.
Well……..
“Man I love it, didn't think I would so much, these bikes are great, when can we get mine going again?”
Guess Black Betty's going to have to wait a little bit longer.
LOL, will do 2M.
Yup - I've said it before. A stock Yamaha XS650 is a really really good motorcycle.
It's isn't the fastest, or the best handling, nor does it stop like a modern sport bike - but for general booting around and enjoy the breeze, you can't beat it!
It's isn't the fastest, or the best handling, nor does it stop like a modern sport bike - but for general booting around and enjoy the breeze, you can't beat it!
I have spent some time today investigating and going through 2M's tests in post #168 and have some carb and timing results and questions so will discuss each in a separate post.
First of all, thanks for these tests 2M, I am intrigued by these carbs and all these little things add to the knowledge base of tests to perform.
I photographed and documented as per your butterfly/transition port pictures in post #90.
Your 1/4 turn pic equates to a full turn for me. 1st transition port just visible.
Your 1/2 turn pic is my 1 1/4 turn.
If I set butterfly's so that 1st transition port is just visible I am at about 5 threads visible on the throttle stop screw, which appears to be consistent with gggGary's 5-6 threads out shown in his pics in post #94.
I have not synced the carbs on the bike yet. My right side exhaust is blown out as seen below, so attempting to sync by feeling equal pressure is pretty much impossible. This is pretty much the way it came to me in 1990, although I would expect it has gotten worse over the years. My next job is to put together an ATF manometer.
It starts and idles with stop screw out 1 turn, but wants to stall. At 1 1/4 turns out, just past exposing 1st transition port, it smooths out and idles at 1200 RPM. This is still at gggGary's 5 -6 threads exposed.
Mix screws set by ear as per DogBunny and 5twins, which it turns out is pretty easy to hear the subtle changes.
Factory spec - 2 1/4 turns out. I'm seem to be at the sweet spot at Right - 2 3/4, Left 1 3/4.
Took your exam, answers below, hope I passed.....lol.
1)
I'm guessing this means choke plunger tips are OK so no fuel is leaking past?
2)
So would this show diaphragms are good, no leaks?
3)
4)
I have just read a comment by 5twins in another thread re: BS34's, that both mix screws should be the same, don't know if this applies to BS38's as well?
Would I be correct in thinking that final syncing with a manometer should smooth things out further and allow me to adjust my mix screws closer to each other?
Thanks for all help and suggestions.
First of all, thanks for these tests 2M, I am intrigued by these carbs and all these little things add to the knowledge base of tests to perform.
I photographed and documented as per your butterfly/transition port pictures in post #90.
Your 1/4 turn pic equates to a full turn for me. 1st transition port just visible.
Your 1/2 turn pic is my 1 1/4 turn.
If I set butterfly's so that 1st transition port is just visible I am at about 5 threads visible on the throttle stop screw, which appears to be consistent with gggGary's 5-6 threads out shown in his pics in post #94.
I have not synced the carbs on the bike yet. My right side exhaust is blown out as seen below, so attempting to sync by feeling equal pressure is pretty much impossible. This is pretty much the way it came to me in 1990, although I would expect it has gotten worse over the years. My next job is to put together an ATF manometer.
It starts and idles with stop screw out 1 turn, but wants to stall. At 1 1/4 turns out, just past exposing 1st transition port, it smooths out and idles at 1200 RPM. This is still at gggGary's 5 -6 threads exposed.
Mix screws set by ear as per DogBunny and 5twins, which it turns out is pretty easy to hear the subtle changes.
Factory spec - 2 1/4 turns out. I'm seem to be at the sweet spot at Right - 2 3/4, Left 1 3/4.
Took your exam, answers below, hope I passed.....lol.
1)
Negatory Big Ben
I'm guessing this means choke plunger tips are OK so no fuel is leaking past?
2)
No mood changes.
So would this show diaphragms are good, no leaks?
3)
Yes, it will stall on each carb. This proves that pilot circuit is clean and functioning properly so additional air boost leans it out too much to run?
4)
Yes, dizziness occurs. This was the hardest part of the exam. Had to set for a spell.
I have just read a comment by 5twins in another thread re: BS34's, that both mix screws should be the same, don't know if this applies to BS38's as well?
Would I be correct in thinking that final syncing with a manometer should smooth things out further and allow me to adjust my mix screws closer to each other?
Thanks for all help and suggestions.
I imagine the real answer to my questions here are a Pamco and E-advance but that isn't really in the budget right now. However would be cheaper than a holed piston.
As mentioned above: Set points: Dwell spec 88° to 98°, got these to 92° - 23° on 4 cylinder setting on YM dwell meter.
My timing is set quite retarded with timing light to right line of |F|. At full advance I am getting some bounce past the mark.
I see the Factory Manual and Clymers state that there is a 3mm tolerance either side of the full advance mark. I am getting 3mm (maybe close to 4mm sometimes) bounce past. Seems to be a little worse on the left side.
Advance rod was lubed with high moly grease this spring.
1) Would this indicate my advance unit is worn?
2) Factory manual says to bend the advance stops to limit advance. Clymers says not too which also seems to be the general consensus here as they would fracture and eventually break.
Would peening the advance weight tangs help with this?
3) Could this much bounce past/advanced timing at full advance potentially hole a piston?
Once again thanks for all suggestions and advice.
As mentioned above: Set points: Dwell spec 88° to 98°, got these to 92° - 23° on 4 cylinder setting on YM dwell meter.
My timing is set quite retarded with timing light to right line of |F|. At full advance I am getting some bounce past the mark.
I see the Factory Manual and Clymers state that there is a 3mm tolerance either side of the full advance mark. I am getting 3mm (maybe close to 4mm sometimes) bounce past. Seems to be a little worse on the left side.
Advance rod was lubed with high moly grease this spring.
1) Would this indicate my advance unit is worn?
2) Factory manual says to bend the advance stops to limit advance. Clymers says not too which also seems to be the general consensus here as they would fracture and eventually break.
Would peening the advance weight tangs help with this?
3) Could this much bounce past/advanced timing at full advance potentially hole a piston?
Once again thanks for all suggestions and advice.
Hey Robin, another thorough and methodical approach, and a nice write up. With regards to getting your mix screws the same, I'm sure those more knowledgable than I will weigh in here, but I think variances in individual cylinders, compression and condition of the valves and seals and such make it hard to get them set in exactly the same turns out. I know on my bike the left cylinder needs a little more gas than the right to be happy. Maybe it's my worn carburetor body / butterfly that's causing that.
Like you I just tuned my carbs by ear, I have a freshly made manometer just hanging in the garage, but it's running pretty sweet right now and I'm tempted to just leave well enough alone.
Like you I just tuned my carbs by ear, I have a freshly made manometer just hanging in the garage, but it's running pretty sweet right now and I'm tempted to just leave well enough alone.
Thanks Bob, and yes that all makes sense. In the past I never paid attention to how they were in comparison to each other. Just got it to run well. Or relatively well.
Interested this time round in understanding things a little better, so I can tune better and take better care of these old girls.
And don't blame ya, let sleeping dogs lie.....lol.
Interested this time round in understanding things a little better, so I can tune better and take better care of these old girls.
And don't blame ya, let sleeping dogs lie.....lol.
Mix screw settings should be pretty close carb to carb even on the 38s. Maybe your rotted out muffler has something to do with it. It will be hard to tune the carbs with 2 mufflers that flow differently. I'd buy a set of the Commando mufflers.
Your timing isn't really that retarded. Both sides of the "F" mark represent the idle timing range. It is 13° to 17° BTDC, so you're set down around 12° or 13°. But, remember that the timing spec used to be different when these bikes first came out. It was 10° to 15° BTDC. You're pretty much right in the middle of that, and I think it runs better like this. You could probably even retard it another degree or 2 if you're concerned with that "bounce" past the full advance mark.
I get a small amount of "bounce" on mine. It's almost like a "phantom" image with the timing light. I can see it but it's not as defined or dark as the main firing image. It was worse. I improved it quite a bit by shimming the excess in-out end play out of my advance rod. There's some details here .....
http://xs650temp.proboards.com/thread/1372?page=2
I have my timing set like yours, over by the right slash mark at idle. That puts the main image on the timing light maybe a small 1/8" before the full advance slash mark, and the occasional "bounce" or "phantom" image I still occasionally get pretty much on the slash (but not past).
Your timing isn't really that retarded. Both sides of the "F" mark represent the idle timing range. It is 13° to 17° BTDC, so you're set down around 12° or 13°. But, remember that the timing spec used to be different when these bikes first came out. It was 10° to 15° BTDC. You're pretty much right in the middle of that, and I think it runs better like this. You could probably even retard it another degree or 2 if you're concerned with that "bounce" past the full advance mark.
I get a small amount of "bounce" on mine. It's almost like a "phantom" image with the timing light. I can see it but it's not as defined or dark as the main firing image. It was worse. I improved it quite a bit by shimming the excess in-out end play out of my advance rod. There's some details here .....
http://xs650temp.proboards.com/thread/1372?page=2
I have my timing set like yours, over by the right slash mark at idle. That puts the main image on the timing light maybe a small 1/8" before the full advance slash mark, and the occasional "bounce" or "phantom" image I still occasionally get pretty much on the slash (but not past).
Excellent 5twins, thank you. New pipes are on the wish list, I will look into a set of them.
I will spend a little more time looking at this. IIRC it is a little more than just a phantom image, and will register as 3-4mm too advanced at 3000-3500 rpm, so maybe more than just a little "bounce". But with your description here, it gives me a better way to judge this. I didn't know if I should be concerned or not. As long as I'm not going to do any damage to the engine, I'll finish tuning and ride it until I get Pamco and E-advance.
I know there is some end play in the advance rod so will try your shimming trick.
Thanks again for the info and advice.
I will spend a little more time looking at this. IIRC it is a little more than just a phantom image, and will register as 3-4mm too advanced at 3000-3500 rpm, so maybe more than just a little "bounce". But with your description here, it gives me a better way to judge this. I didn't know if I should be concerned or not. As long as I'm not going to do any damage to the engine, I'll finish tuning and ride it until I get Pamco and E-advance.
I know there is some end play in the advance rod so will try your shimming trick.
Thanks again for the info and advice.
Robinc, thanx for your info on the butterfly plates, transition port, and idle stop screw. The 3/4 turn difference is significant, it helps with my diagnosing of my warped carbs. It's running fine, just a pet project. More number crunching.
I like quick, simple, cheap tests. Especially if they give multiple clues. Ex, a test can give you "no change", "improvement", "worse", "rpms rise", "rpms drop". Where it can get confusing is that some of these tests aren't necessarily "direct", they're part of an overall picture, like a jigsaw puzzle. Google "mastermind game".
Yes, pressing down on the choke plungers can tell you if they're sealing fuel, but only if the plunger body is leaking air. Covering the half-moon vent can tell you if the plunger body isn't blocking air, since its air source comes from under the diaphragm. Again, these aren't necessarily definitive tests, as in failure = replace part. Just more clues.
********
There is a fuel premix stage, where air from the air bleeds (orificed vents) intermixes with the fuel delivered thru a jet. On typical carbs this is done within an emulsifier tube, with multiple air-entry holes on the sides, and the air bubbles (verb) into the jet's fuel stream, percolating it into an aerated foam, which flows onward thru the delivery passages. This aerated fuel has features that are important to the carb's function.
First, it initiates the vaporization stage. Each little bubble is loaded with vaporized fuel.
Second it reduces the "splashing" effect. Large gloms of raw liquid are difficult to control. Your kitchen and bath faucets purposely have aerators. Run the water without the aerator, and watch the water splash everywhere. Aeration is a plumbing standard to eliminate that splashing, giving you a gentler water stream that doesn't splash.
Third, this aerated, foamy fuel has a much lighter density, and will respond much more rapidly to subtle changes in passageway pressures. The intake draw during the intake stroke is non-linear, occurs rapidly and at a high frequency (1/2 rpm), and must also deal with other pressure pulses, like bouncing acoustic waves. No wonder fuel injection is superior, it doesn't have to fuss with all that.
**********
Your blowing air from a tube into the air bleeds lets us know if the bleeds may be blocked, but not the quality of the bleed mix ratio. Adjusting how much air is blown in those can give more clues.
Unfortunately, I neglected to ask you to do the complimentary test, blocking the air bleeds. Knowing now their function, how would you interpret the results?
I'm reminded of an explaination of colliders used in particle physics:
"Were trying to figure out what makes up the atom, by bombarding it with high energy particles. Much like trying to figure out how a piano is built, by pushing it down a flight of stairs, and listening to the ensuing carnage."
Good grief. Sleep deprivation, and too much coffee.
Your non-equal mix screw settings, and plug readings are also clues.
I hope the problem simply boils down to simple carb syncing and followup adjustments. But, when things get wierd you have to fall back on the theory of operation, keeping in mind that a lot of this stuff is no longer factory pristine, with nefarious histories, and new, possibly undiscovered, problems from "age".
I like quick, simple, cheap tests. Especially if they give multiple clues. Ex, a test can give you "no change", "improvement", "worse", "rpms rise", "rpms drop". Where it can get confusing is that some of these tests aren't necessarily "direct", they're part of an overall picture, like a jigsaw puzzle. Google "mastermind game".
Yes, pressing down on the choke plungers can tell you if they're sealing fuel, but only if the plunger body is leaking air. Covering the half-moon vent can tell you if the plunger body isn't blocking air, since its air source comes from under the diaphragm. Again, these aren't necessarily definitive tests, as in failure = replace part. Just more clues.
********
There is a fuel premix stage, where air from the air bleeds (orificed vents) intermixes with the fuel delivered thru a jet. On typical carbs this is done within an emulsifier tube, with multiple air-entry holes on the sides, and the air bubbles (verb) into the jet's fuel stream, percolating it into an aerated foam, which flows onward thru the delivery passages. This aerated fuel has features that are important to the carb's function.
First, it initiates the vaporization stage. Each little bubble is loaded with vaporized fuel.
Second it reduces the "splashing" effect. Large gloms of raw liquid are difficult to control. Your kitchen and bath faucets purposely have aerators. Run the water without the aerator, and watch the water splash everywhere. Aeration is a plumbing standard to eliminate that splashing, giving you a gentler water stream that doesn't splash.
Third, this aerated, foamy fuel has a much lighter density, and will respond much more rapidly to subtle changes in passageway pressures. The intake draw during the intake stroke is non-linear, occurs rapidly and at a high frequency (1/2 rpm), and must also deal with other pressure pulses, like bouncing acoustic waves. No wonder fuel injection is superior, it doesn't have to fuss with all that.
**********
Your blowing air from a tube into the air bleeds lets us know if the bleeds may be blocked, but not the quality of the bleed mix ratio. Adjusting how much air is blown in those can give more clues.
Unfortunately, I neglected to ask you to do the complimentary test, blocking the air bleeds. Knowing now their function, how would you interpret the results?
I'm reminded of an explaination of colliders used in particle physics:
"Were trying to figure out what makes up the atom, by bombarding it with high energy particles. Much like trying to figure out how a piano is built, by pushing it down a flight of stairs, and listening to the ensuing carnage."
Good grief. Sleep deprivation, and too much coffee.
Your non-equal mix screw settings, and plug readings are also clues.
I hope the problem simply boils down to simple carb syncing and followup adjustments. But, when things get wierd you have to fall back on the theory of operation, keeping in mind that a lot of this stuff is no longer factory pristine, with nefarious histories, and new, possibly undiscovered, problems from "age".
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A common problem with our mechanical spark advancers is the wear of the tiny flyweight ears within the slotted disc's slots. A little slop in there translates to large variances in ignition timing. Not much fix for that. RetiredGentleman and some others had resorted to hammer flattening the ears, widening them, reducing the slop. I built up mig welds on mine, and ground back to shape.
The aftermarket advance unit is of lesser quality, and has a history of catastrophic failure. Best to just bypass all that and follow RetiredGentleman's Pamco/E-advancer path.
The video in these threads shows my ignition timing, with its little fluctuations. I'd rather that it wouldn't jump as much as it does, but it runs just fine.
http://www.xs650.com/threads/an-led-ignition-timing-light-experiment.44586/
http://www.xs650.com/threads/xs650-ignition-timing-revisited-are-we-too-advanced.45197/
The aftermarket advance unit is of lesser quality, and has a history of catastrophic failure. Best to just bypass all that and follow RetiredGentleman's Pamco/E-advancer path.
The video in these threads shows my ignition timing, with its little fluctuations. I'd rather that it wouldn't jump as much as it does, but it runs just fine.
http://www.xs650.com/threads/an-led-ignition-timing-light-experiment.44586/
http://www.xs650.com/threads/xs650-ignition-timing-revisited-are-we-too-advanced.45197/
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Wow, thanks for all the info 2M.
I will have to sit with a cuppa and digest for awhile.
As far as blocking the ports, I would think blocking the pilot port at idle will stall as there would be no air supply to the pilot/idle circuit which would be the most sensitive circuit.
Blocking the main port at idle will have no effect as this circuit isn't operational yet, but blocking it at higher RPM's would probably causing stumble/stall.
Will try this out later today.
It is running well enough to ride, which I gotta do, but would like to get things a little closer if I can.
I noticed that your timing is set further retarded than what I have mine set to.
I am directly over the line to the right of the F, which 5twins tells me is about 12° or 13° BTDC. Yours appears to be more like 10°.
Gonna play a little more with carb mix, then sync, then will hook up the light again to verify if full advance timing is actually residing to the left of full advance or just a "phantom" "bounce" past image.
I don't know how long it would take to hole a piston, and if I being to the left of full advance by 3° or 4°could do that, obviously don't want to run it much.
If I see it staying there might try retarding a little more as 5twins suggested.
If no luck, guess I'll have to bite the upgrade bullet sooner than planned.
Once again, thanks for all your help!
Have a great day.
I will have to sit with a cuppa and digest for awhile.
As far as blocking the ports, I would think blocking the pilot port at idle will stall as there would be no air supply to the pilot/idle circuit which would be the most sensitive circuit.
Blocking the main port at idle will have no effect as this circuit isn't operational yet, but blocking it at higher RPM's would probably causing stumble/stall.
Will try this out later today.
It is running well enough to ride, which I gotta do, but would like to get things a little closer if I can.
I noticed that your timing is set further retarded than what I have mine set to.
I am directly over the line to the right of the F, which 5twins tells me is about 12° or 13° BTDC. Yours appears to be more like 10°.
Gonna play a little more with carb mix, then sync, then will hook up the light again to verify if full advance timing is actually residing to the left of full advance or just a "phantom" "bounce" past image.
I don't know how long it would take to hole a piston, and if I being to the left of full advance by 3° or 4°could do that, obviously don't want to run it much.
If I see it staying there might try retarding a little more as 5twins suggested.
If no luck, guess I'll have to bite the upgrade bullet sooner than planned.
Once again, thanks for all your help!
Have a great day.
