setting the timing and confirming the auto advance unit on one of those really is simple
perhaps you are not looking or feeling it correctly
my guess is walking you thru it online would be quite simple although it would seem to me that there would be plenty local to you that could do it in their sleep
these are very very very simple engines
if you want help online............ be very specific and detailed with what is going on and how things are
and ask direct and specific questions too
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Anybody in L.A. know how to fix/tune an R60US?
Anybody in L.A. know how to fix/tune an R60US?
Hey EuroIron,
I wish it was that simple. I have set the engine and timing per the info I got from Vech. I am beginning to think that I may have a defective advance unit but because this is the first airhead I've ever worked on I am not sure what to look for. Here's what I've done;
1) Made sure the "S" mark is lined up in the timing window.
2) Aligned the notch in the magneto assembly with the notch in the magnet.
3) Bolted the advance back on the end of the shaft making sure that the little notch aligns in the slot and both notches on magnet and magneto housing are aligned.
4) Set points gap to .015 inches.
5) Used the static method to set timing.
It takes about 6 to 12 kicks to get the bike to fire. Runs rough at idle. As I give it gas it runs even worse and begins to backfire. (Carbs were rebuilt with all adjustments set to Bing specifications). Advancing or retarding the timing (by moving the points plate per Vech) doesn't seem to matter. I have even tried to rotate the magneto housing to see if that helps. It doesn't.
Any ideas?
I wish it was that simple. I have set the engine and timing per the info I got from Vech. I am beginning to think that I may have a defective advance unit but because this is the first airhead I've ever worked on I am not sure what to look for. Here's what I've done;
1) Made sure the "S" mark is lined up in the timing window.
2) Aligned the notch in the magneto assembly with the notch in the magnet.
3) Bolted the advance back on the end of the shaft making sure that the little notch aligns in the slot and both notches on magnet and magneto housing are aligned.
4) Set points gap to .015 inches.
5) Used the static method to set timing.
It takes about 6 to 12 kicks to get the bike to fire. Runs rough at idle. As I give it gas it runs even worse and begins to backfire. (Carbs were rebuilt with all adjustments set to Bing specifications). Advancing or retarding the timing (by moving the points plate per Vech) doesn't seem to matter. I have even tried to rotate the magneto housing to see if that helps. It doesn't.
Any ideas?
Anybody in L.A. know how to fix/tune an R60US?
well nice is to have a timing light so you can actually watch the timing change as the engine is running
let's assume the advance unit is stuck and not advancing the timing... the engine, if all else is well, will start just fine, run smoothly, but will have very poor throttle response and sound flat
let's assume the advance unit is simply not smooth in operation....... typically they will start just fine, although if really sticky the advance may not fully retard at kicking to idle speeds and kicking may sometimes be a kick back proposition........ often they will not settle down quickly to a slow idle
but generally simple timing errors won't make an engine run rough in general unless the errors are huge
you can physically inspect the auto advance unit for smooth motion
just put your fingers and eyes on it
it should be able to move to the fully advanced position and pretty much move smartly back to the retarded position once you release it
if it doesn't, keep in mind that this unit is indeed a service item yet one very often neglected, so by all means, take it apart, clean and polish all friction and bearing type surfaces, lube it and put it back together, it should work if it's not worn out
btw.......... I think the prudent method of static timing is to actually time it fully advanced........ which means line up the full advance mark and then manually advance the auto advance unit, making sure the points break there although this may leave you wishing for a few extra hands and a bit more patience than static timing in the retarded position
this is in case you don't have a timing light
if there is a timing error........ it is very unlikely to hole a piston if the error is at slow engine speed
however....... if the error is at full advance engine speeds........ somewhere between 3 and 4000 rpm......... you could have bad results
and always, check timing on both cylinders and "split the difference" if there is the unlikely but possible full advance error between two cylinders
so after all this......... it sounds to me like you need to do a compression check after you confirm the valve adjustments are within spec
if that is ok, look carefully at your plugs and don't be the least bit hesitant to change them even with a step or two hotter just to get it starting and running reliably without fouling plugs
I think you can get Iridium plugs for these bikes now...... highly recommended as they are very effective for low energy ignition system'd engines and the low compression doesn't help the spark plug situation at all either
check the points stationary and movable contacts an use a magnifying glass (and keep that handy for the carbs if you have to go there) if you don't have great up close eyes........ you are looking for signs of metal transfer and if you see any........ noting if from movable to stationary......... or vice versa....... is very helpful in pointing to a failing or improperly valued coil or condenser
then......... you will want to confirm you have adequate ignition energy....... easy enough for an oil coil to start laying down or the rotor magnet to become weak
see how large a pair of gaps the ignition will jump in open air..... note when it stops being fat and blue
there are recent threads that discuss this in detail for you to reference
if the ignition is good.........
then maybe you simply have a cable or resulting slide sync problem....... maybe a vacuum leak...... who knows
if not then maybe you've managed to get some trash inside the carbs from having a tank not as clean as your freshly oh'd carbs........ doesn't take much to stop up an idle jet or transfer hole
hopefully if you have to go inside the carbs, you will find them clean and hopefully all you'll have to do is blow out some debris out of a possibly stopped jet..... if not so easy then you can.....
tiny pinpoint brush out of a bit of expired cable inner...... you can crimp on a butt connector handle
and nice is that the finer cables have a single strand that will allow you to carefully wire thru even the tiny holes in the idle circuits without boring them oversize
oh one more thing or two........ make sure you are using reasonably fresh gas........ I generally save stuff more than a couple weeks old for daily driven and reliably starting things
if it's aged at all, smells like shellac in the slightest, or a visual reveals trash or sediment in the tank, drain it and put in some fresh and probably wouldn't hurt to put some from the shaken or stirred tank into a settling glass or jar to inspect it for trash or water
of course if there is trash or sediment in the tank, clean and rinse it well
those simple things can be most annoying sometime
was it running fine prior to it all the sudden needing the ignition timed?
tell more about what it is now doing, how it did before, when was before, and what happened
and anything else that may be helpful if you don't nail it already
good luck
let's assume the advance unit is stuck and not advancing the timing... the engine, if all else is well, will start just fine, run smoothly, but will have very poor throttle response and sound flat
let's assume the advance unit is simply not smooth in operation....... typically they will start just fine, although if really sticky the advance may not fully retard at kicking to idle speeds and kicking may sometimes be a kick back proposition........ often they will not settle down quickly to a slow idle
but generally simple timing errors won't make an engine run rough in general unless the errors are huge
you can physically inspect the auto advance unit for smooth motion
just put your fingers and eyes on it
it should be able to move to the fully advanced position and pretty much move smartly back to the retarded position once you release it
if it doesn't, keep in mind that this unit is indeed a service item yet one very often neglected, so by all means, take it apart, clean and polish all friction and bearing type surfaces, lube it and put it back together, it should work if it's not worn out
btw.......... I think the prudent method of static timing is to actually time it fully advanced........ which means line up the full advance mark and then manually advance the auto advance unit, making sure the points break there although this may leave you wishing for a few extra hands and a bit more patience than static timing in the retarded position
this is in case you don't have a timing light
if there is a timing error........ it is very unlikely to hole a piston if the error is at slow engine speed
however....... if the error is at full advance engine speeds........ somewhere between 3 and 4000 rpm......... you could have bad results
and always, check timing on both cylinders and "split the difference" if there is the unlikely but possible full advance error between two cylinders
so after all this......... it sounds to me like you need to do a compression check after you confirm the valve adjustments are within spec
if that is ok, look carefully at your plugs and don't be the least bit hesitant to change them even with a step or two hotter just to get it starting and running reliably without fouling plugs
I think you can get Iridium plugs for these bikes now...... highly recommended as they are very effective for low energy ignition system'd engines and the low compression doesn't help the spark plug situation at all either
check the points stationary and movable contacts an use a magnifying glass (and keep that handy for the carbs if you have to go there) if you don't have great up close eyes........ you are looking for signs of metal transfer and if you see any........ noting if from movable to stationary......... or vice versa....... is very helpful in pointing to a failing or improperly valued coil or condenser
then......... you will want to confirm you have adequate ignition energy....... easy enough for an oil coil to start laying down or the rotor magnet to become weak
see how large a pair of gaps the ignition will jump in open air..... note when it stops being fat and blue
there are recent threads that discuss this in detail for you to reference
if the ignition is good.........
then maybe you simply have a cable or resulting slide sync problem....... maybe a vacuum leak...... who knows
if not then maybe you've managed to get some trash inside the carbs from having a tank not as clean as your freshly oh'd carbs........ doesn't take much to stop up an idle jet or transfer hole
hopefully if you have to go inside the carbs, you will find them clean and hopefully all you'll have to do is blow out some debris out of a possibly stopped jet..... if not so easy then you can.....
tiny pinpoint brush out of a bit of expired cable inner...... you can crimp on a butt connector handle
and nice is that the finer cables have a single strand that will allow you to carefully wire thru even the tiny holes in the idle circuits without boring them oversize
oh one more thing or two........ make sure you are using reasonably fresh gas........ I generally save stuff more than a couple weeks old for daily driven and reliably starting things
if it's aged at all, smells like shellac in the slightest, or a visual reveals trash or sediment in the tank, drain it and put in some fresh and probably wouldn't hurt to put some from the shaken or stirred tank into a settling glass or jar to inspect it for trash or water
of course if there is trash or sediment in the tank, clean and rinse it well
those simple things can be most annoying sometime
was it running fine prior to it all the sudden needing the ignition timed?
tell more about what it is now doing, how it did before, when was before, and what happened
and anything else that may be helpful if you don't nail it already
good luck
-
schrader7032
- Posts: 9038
- Joined: Fri Oct 27, 2006 3:00 am
- Location: San Antonio, TX
- Has thanked: 2 times
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Anybody in L.A. know how to fix/tune an R60US?
Here's what I've done;
1) Made sure the "S" mark is lined up in the timing window.
2) Aligned the notch in the magneto assembly with the notch in the magnet.
3) Bolted the advance back on the end of the shaft making sure that the little notch aligns in the slot and both notches on magnet and magneto housing are aligned.
4) Set points gap to .015 inches.
5) Used the static method to set timing.
You may have left some of the details out, but I'm wondering what exactly you did for 4). You set the magneto timing with the flywheel showing the "S" mark in the window. However, to set the points gap, you must rotate the engine so that the rubbing block on the points rides on the highest point of the advance cam...it won't be on the "S" mark when you're doing this. Once that is done, then you continue to rotate the engine and watch/listen for the points to just open when the "S" mark comes back in the window.
You can use an ohmeter to monitor the physical break in the points (the ohmeter, in the beeping mode, will be beep as long as the points are closed but will stop beeping the instant the points open). You'll need to disconnect a ground wire at one end of the points. Or you can pull a plug, reinstall it in the cable, and lay it against the engine fins. Now turn the engine and listen for the crack of the spark.
Maybe you already did this but you kind of skipped over that important step in your description.
Kurt in S.A.
1) Made sure the "S" mark is lined up in the timing window.
2) Aligned the notch in the magneto assembly with the notch in the magnet.
3) Bolted the advance back on the end of the shaft making sure that the little notch aligns in the slot and both notches on magnet and magneto housing are aligned.
4) Set points gap to .015 inches.
5) Used the static method to set timing.
You may have left some of the details out, but I'm wondering what exactly you did for 4). You set the magneto timing with the flywheel showing the "S" mark in the window. However, to set the points gap, you must rotate the engine so that the rubbing block on the points rides on the highest point of the advance cam...it won't be on the "S" mark when you're doing this. Once that is done, then you continue to rotate the engine and watch/listen for the points to just open when the "S" mark comes back in the window.
You can use an ohmeter to monitor the physical break in the points (the ohmeter, in the beeping mode, will be beep as long as the points are closed but will stop beeping the instant the points open). You'll need to disconnect a ground wire at one end of the points. Or you can pull a plug, reinstall it in the cable, and lay it against the engine fins. Now turn the engine and listen for the crack of the spark.
Maybe you already did this but you kind of skipped over that important step in your description.
Kurt in S.A.
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2
Fast. Neat. Average. Friendly. Good. Good.
'78 R100/7 '69 R69S '52 R25/2
Fast. Neat. Average. Friendly. Good. Good.
Anybody in L.A. know how to fix/tune an R60US?
Hey all thanks for the great input but I got it figured out! The problem is that the notch on the end of the magneto magnet shaft was larger than it should be so everytime I would tighten up the bolt holding the advance on it would rotate the advance about 7 to 10 degrees retarded. (It looks like I need to find a new magneto magnet). My temporary fix is to compensate for that by rotating the magnet a little advanced and also running the points advanced.
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Allan.Atherton
- Posts: 503
- Joined: Fri Oct 27, 2006 3:00 am
Anybody in L.A. know how to fix/tune an R60US?
... the notch on the end of the magneto magnet shaft was larger than it should be so everytime I would tighten up the bolt holding the advance on it would rotate the advance about 7 to 10 degrees retarded.... My temporary fix is to compensate for that by rotating the magnet a little advanced and also running the points advanced.
Rotating the magneto body and overadvancing the points plate to compensate would seem to disturb the ideal abrisz adjustment.
It is common for the notch and the tab to get mushed out and fit loosely such that the advance wiggles back and forth. Every time you loosen it, or take it off and replace it, it will be in a different place, making consistent timing impossible.
Unless it is extremely loose, the usual fix is to just turn the advance clockwise to the end of its loose fit, and hold it there while tightening the nut.
Rotating the magneto body and overadvancing the points plate to compensate would seem to disturb the ideal abrisz adjustment.
It is common for the notch and the tab to get mushed out and fit loosely such that the advance wiggles back and forth. Every time you loosen it, or take it off and replace it, it will be in a different place, making consistent timing impossible.
Unless it is extremely loose, the usual fix is to just turn the advance clockwise to the end of its loose fit, and hold it there while tightening the nut.
Anybody in L.A. know how to fix/tune an R60US?
Rotating the magneto body and overadvancing the points plate to compensate would seem to disturb the ideal abrisz adjustment.
Ideally I agree but the handful of vintage bikes I've actually taken the time to set up the o-scope and degree wheel on to check this........ for either the charging (nice to have it peak correctly for battery-less DC ignition) or other various ET ignitions like the bmw magneto
have all had errors in the as marked index of peak output and some beyond 7 degrees......... seen enough precision things on the BMW's to hope they are all manufactured so as for this mark to be 100% correct, even with mixing and matching, but the odds against that are huge, from a jaded pragmatist's point of view.
to peak the rotor on one of my kick only batteryless bikes, it required a one-off offset key to be made and consumed almost a complete half day just to scientifically verify it needed it.
Has anyone ever bothered checking this on the old BMW's ?
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Allan.Atherton
- Posts: 503
- Joined: Fri Oct 27, 2006 3:00 am
Anybody in L.A. know how to fix/tune an R60US?
Rotating the magneto body and overadvancing the points plate to compensate would seem to disturb the ideal abrisz adjustment.
Ideally I agree but the handful of vintage bikes I've actually taken the time to set up the o-scope and degree wheel on to check this........ for either the charging (nice to have it peak correctly for battery-less DC ignition) or other various ET ignitions like the bmw magneto
have all had errors in the as marked index of peak output and some beyond 7 degrees......... seen enough precision things on the BMW's to hope they are all manufactured so as for this mark to be 100% correct, even with mixing and matching, but the odds against that are huge, from a jaded pragmatist's point of view.
to peak the rotor on one of my kick only batteryless bikes, it required a one-off offset key to be made and consumed almost a complete half day just to scientifically verify it needed it.
Has anyone ever bothered checking this on the old BMW's ?
All I know about the abrisz 3-point alignment for peak spark comes from Vech's web page on magneto setup at http://members.aol.com/VechBMW/tech.html -- and that's how I set up my bikes.
My point was just that rotating magneto body to compensate for a sloppy advance unit notch was not the best way to handle that problem.
Anybody in L.A. know how to fix/tune an R60US?
certainly I agree that the magneto does need to be correctly phased for best results but there is some wiggle room engineered in which is proven each and every time the auto-advance unit does it thing without moving the rotor relative to the crankshaft.......... like a Lucas on a Norton whose engine driven auto-advance unit drives, advances, and retards a constantly phased magneto
but the method to which you post a link places 100% faith that any key-ways, locater dowels, and scribed marks are absolutely error free
it's certainly a great thing to do and should even be part of the service manual and yes I agree the solution about could stack up and result in reduced spark output........ but without really looking at it....... it could also be better at fully advanced or retarded...... since there is that compromise involving the auto-advance or even manual advance unit
my point is that is very optimistic and highly unlikely such faith in manually machined old pieces will produce perfection and would even venture as far to say it would be a safe bet that is ten bikes were set up that way with vintage parts....... ... more than half would have errors that more probing scientific test equipment could easily verify....... and just because an error is anything not perfect
and I am only speaking in terms of absolutely knowing when peak flux is actually generated as opposed to double checking the handful of humans that did the associated machine work on the various pieces
having something a half degree, or more, out of index happens even with todays ultra precise CNC equipment........ being on one side or the other of a tolerance does as well...... and there are several pieces which were manually machined that can all stack up to result in error
so I am just splitting hairs is all and asking if anyone has ever delved any deeper into the actual phasing other than just lining up all the marks
I'm sure much more productive and effective would be to come up with a bonafide neo-dy rotor for these and a stouter coil to transfer the extra energy produced by it
but the method to which you post a link places 100% faith that any key-ways, locater dowels, and scribed marks are absolutely error free
it's certainly a great thing to do and should even be part of the service manual and yes I agree the solution about could stack up and result in reduced spark output........ but without really looking at it....... it could also be better at fully advanced or retarded...... since there is that compromise involving the auto-advance or even manual advance unit
my point is that is very optimistic and highly unlikely such faith in manually machined old pieces will produce perfection and would even venture as far to say it would be a safe bet that is ten bikes were set up that way with vintage parts....... ... more than half would have errors that more probing scientific test equipment could easily verify....... and just because an error is anything not perfect
and I am only speaking in terms of absolutely knowing when peak flux is actually generated as opposed to double checking the handful of humans that did the associated machine work on the various pieces
having something a half degree, or more, out of index happens even with todays ultra precise CNC equipment........ being on one side or the other of a tolerance does as well...... and there are several pieces which were manually machined that can all stack up to result in error
so I am just splitting hairs is all and asking if anyone has ever delved any deeper into the actual phasing other than just lining up all the marks
I'm sure much more productive and effective would be to come up with a bonafide neo-dy rotor for these and a stouter coil to transfer the extra energy produced by it
-
Allan.Atherton
- Posts: 503
- Joined: Fri Oct 27, 2006 3:00 am
Anybody in L.A. know how to fix/tune an R60US?
... the method to which you post a link places 100% faith that any key-ways, locater dowels, and scribed marks are absolutely error free...
Well, that page by Vech is the best we have got on the subject. At least it keeps people from timing their engines by rotating the magneto body instead of the points plate.
Well, that page by Vech is the best we have got on the subject. At least it keeps people from timing their engines by rotating the magneto body instead of the points plate.