Posted by Ash on August 4, 2008, 12:47 am
Hello everyone,
I am in the process of making an old Z1B road worthy again. This
has been a 3-year project and I feel that it is almost there, but I am
stumped on what appears to be an ignition problem.
Here are the facts:
)New battery, no problem getting engine to turn over.
)Spark plugs are functional
)Timing chain has been checked and re-checked. Pins have been counted
and the marks on the cams have been aligned with the head as directed
in the factory shop manual.
)Carbs have been rebuilt twice (by me). I have had a lot of success
rebuilding Keihin carbs on other projects. These Mikunis are
different, I know, but I am confident that they are functional.
The problem: Engine will not start. When I applied some starting
fluid to give it a little boost, it misfired back through the carbs
and caused the starting fluid in the airbox to ignite. Scared the
hell out of me. Got the fire put out in seconds, so I don't believe
there is any damage to wiring, etc...
Should I give up on dealing with the points and just buy the
electronic ignition system off of ebay? Is it possible that the
condensors (old, and one of the few parts I have not replaced) are
causing this to happen? What should I check next?
Thanks in advance,
-Ash
Posted by MoParMaN on August 4, 2008, 7:54 am
> Hello everyone,
> I am in the process of making an old Z1B road worthy again. This
> has been a 3-year project and I feel that it is almost there, but I am
> stumped on what appears to be an ignition problem.
> Here are the facts:
> )New battery, no problem getting engine to turn over.
> )Spark plugs are functional
> )Timing chain has been checked and re-checked. Pins have been counted
> and the marks on the cams have been aligned with the head as directed
> in the factory shop manual.
> )Carbs have been rebuilt twice (by me). I have had a lot of success
> rebuilding Keihin carbs on other projects. These Mikunis are
> different, I know, but I am confident that they are functional.
> The problem: Engine will not start. When I applied some starting
> fluid to give it a little boost, it misfired back through the carbs
> and caused the starting fluid in the airbox to ignite. Scared the
> hell out of me. Got the fire put out in seconds, so I don't believe
> there is any damage to wiring, etc...
> Should I give up on dealing with the points and just buy the
> electronic ignition system off of ebay? Is it possible that the
> condensors (old, and one of the few parts I have not replaced) are
> causing this to happen? What should I check next?
> Thanks in advance,
> -Ash
Condensers are cheap.
--
MoParMaN--
Posted by . on August 4, 2008, 9:42 am
> )Carbs have been rebuilt twice (by me). �I have had a lot of success
> rebuilding Keihin carbs on other projects. �These Mikunis are
> different, I know, but I am confident that they are functional.
Modern carburetors do not have a flat metal choke plate like a car
carburetor has.
Instead, they have a starting enrichener valve built into the side of
each carb.
When you pull the "choke" knob or raise the "choke" lever, you're
opening the valve and allowing engine vacuum to suck gas straight out
of the float bowl.
But, to get enough engine vacuum, the throttle butterflies (or slides)
have to be closed.
So your starting problem may be as simply as *turning the idle speed
knob all the way counterclockwise*.
When the engine starts, warm it up while nursing the throttle. Once
the engine is warm, set the idle RPM to the manual's specification.
Then the engine should start from cold by just pulling the "choke"
knob and leaving the throttle alone.
Posted by lugnut on August 4, 2008, 8:37 pm
On Sun, 3 Aug 2008 21:47:32 -0700 (PDT), Ash
>Hello everyone,
> I am in the process of making an old Z1B road worthy again. This
>has been a 3-year project and I feel that it is almost there, but I am
>stumped on what appears to be an ignition problem.
>Here are the facts:
>)New battery, no problem getting engine to turn over.
>)Spark plugs are functional
>)Timing chain has been checked and re-checked. Pins have been counted
>and the marks on the cams have been aligned with the head as directed
>in the factory shop manual.
>)Carbs have been rebuilt twice (by me). I have had a lot of success
>rebuilding Keihin carbs on other projects. These Mikunis are
>different, I know, but I am confident that they are functional.
>The problem: Engine will not start. When I applied some starting
>fluid to give it a little boost, it misfired back through the carbs
>and caused the starting fluid in the airbox to ignite. Scared the
>hell out of me. Got the fire put out in seconds, so I don't believe
>there is any damage to wiring, etc...
>Should I give up on dealing with the points and just buy the
>electronic ignition system off of ebay? Is it possible that the
>condensors (old, and one of the few parts I have not replaced) are
>causing this to happen? What should I check next?
>Thanks in advance,
>-Ash
I will give you a couple of things based on my own learning
curve on the "76 I have had for near 33 years. First are
your sure the carbs have fuel in them? I fought the no
start battle late one night after building the carbs and the
fuel valve. Turned out I had assembled the internals of the
fuel valve 180 out so it did not pass fuel in the on
position.
As others have said, a condenser may cause that and new ones
can be bad. Keep in mind the right or front set of points
fires the right coil which is for the 2-3 cylinders and the
left or rear points do the left coil for the 1-4 cylinders.
Use a dime store test light to be sure the correct coil has
power. You can also use the test light to do a preliminary
check for correct ignition timing. It you attach the light
to ground and the points side of the coil, the light will
come on as soon as the points break and you can check the
timing marks for correct timing position. If you have a
DVOM, check your coils for voltage to be sure you are
getting something near battery voltage on the supply. Those
coils should have about 4.2 ohm resistance across the
primary terminal.
BTW, starting fluid does require a spark to ignite. I would
not use it on your bike engine if you like your head gasgets
to seal. Use something like a carb cleaner for testing. It
is best to use nothing other than to check for a fuel
problem. It sounds like you have bad spark or happening at
the wrong time. As for the Dyna S, I think it may be one of
the best things I have ever done for mine. Set it and
forget it. If you have built the head, it will probably
need some valve shim adjustment at or before 5K miles.
After that, I find it is rare for them to need adjustment.
Another thing I highly recommend on any of the old machines
is to put the headlight on a relay. You can get a Ford fuel
pump relay or similar from most parts houses. Wiring
diagrams are here on the net. You need 2 relays, some 16 GA
primary wire and connectors to hook it all up. It is the
best thing you can do for your night time riding. High
wattage bulbs just make the problem worse since the
conductor size and loading is the problem. Same goes for
the ignition feed if you are not getting very close to
battery voltage under load.
Good luck
Lugnut
Posted by Bob Nixon on August 5, 2008, 10:56 am
> On Sun, 3 Aug 2008 21:47:32 -0700 (PDT), Ash
> >Hello everyone,
> > I am in the process of making an old Z1B road worthy again. This
> >has been a 3-year project and I feel that it is almost there, but I am
> >stumped on what appears to be an ignition problem.
> >Here are the facts:
> >)New battery, no problem getting engine to turn over.
> >)Spark plugs are functional
> >)Timing chain has been checked and re-checked. Pins have been counted
> >and the marks on the cams have been aligned with the head as directed
> >in the factory shop manual.
> >)Carbs have been rebuilt twice (by me). I have had a lot of success
> >rebuilding Keihin carbs on other projects. These Mikunis are
> >different, I know, but I am confident that they are functional.
> >The problem: Engine will not start. When I applied some starting
> >fluid to give it a little boost, it misfired back through the carbs
> >and caused the starting fluid in the airbox to ignite. Scared the
> >hell out of me. Got the fire put out in seconds, so I don't believe
> >there is any damage to wiring, etc...
> >Should I give up on dealing with the points and just buy the
> >electronic ignition system off of ebay? Is it possible that the
> >condensors (old, and one of the few parts I have not replaced) are
> >causing this to happen? What should I check next?
> >Thanks in advance,
> >-Ash
> I will give you a couple of things based on my own learning
> curve on the "76 I have had for near 33 years. First are
> your sure the carbs have fuel in them? I fought the no
> start battle late one night after building the carbs and the
> fuel valve. Turned out I had assembled the internals of the
> fuel valve 180 out so it did not pass fuel in the on
> position.
> As others have said, a condenser may cause that and new ones
> can be bad. Keep in mind the right or front set of points
> fires the right coil which is for the 2-3 cylinders and the
> left or rear points do the left coil for the 1-4 cylinders.
> Use a dime store test light to be sure the correct coil has
> power. You can also use the test light to do a preliminary
> check for correct ignition timing. It you attach the light
> to ground and the points side of the coil, the light will
> come on as soon as the points break and you can check the
> timing marks for correct timing position. If you have a
> DVOM, check your coils for voltage to be sure you are
> getting something near battery voltage on the supply. Those
> coils should have about 4.2 ohm resistance across the
> primary terminal.
> BTW, starting fluid does require a spark to ignite.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Bullshit! "Ether" is ignited by compression ignition (like a Diesel)
but at a much lower ratio. Helll, why do you think the stuff even
works on wet ignition systems???
(read this link below)
http://en.wikipedia.org/wiki/Starting_fluid
The rest of your assertions are fine,
I would
> not use it on your bike engine if you like your head gasgets
> to seal. Use something like a carb cleaner for testing. It
> is best to use nothing other than to check for a fuel
> problem. It sounds like you have bad spark or happening at
> the wrong time. As for the Dyna S, I think it may be one of
> the best things I have ever done for mine. Set it and
> forget it. If you have built the head, it will probably
> need some valve shim adjustment at or before 5K miles.
> After that, I find it is rare for them to need adjustment.
> Another thing I highly recommend on any of the old machines
> is to put the headlight on a relay. You can get a Ford fuel
> pump relay or similar from most parts houses. Wiring
> diagrams are here on the net. You need 2 relays, some 16 GA
> primary wire and connectors to hook it all up. It is the
> best thing you can do for your night time riding. High
> wattage bulbs just make the problem worse since the
> conductor size and loading is the problem. Same goes for
> the ignition feed if you are not getting very close to
> battery voltage under load.
> Good luck
> Lugnut- Hide quoted text -
> - Show quoted text -
> I am in the process of making an old Z1B road worthy again. This
> has been a 3-year project and I feel that it is almost there, but I am
> stumped on what appears to be an ignition problem.
> Here are the facts:
> )New battery, no problem getting engine to turn over.
> )Spark plugs are functional
> )Timing chain has been checked and re-checked. Pins have been counted
> and the marks on the cams have been aligned with the head as directed
> in the factory shop manual.
> )Carbs have been rebuilt twice (by me). I have had a lot of success
> rebuilding Keihin carbs on other projects. These Mikunis are
> different, I know, but I am confident that they are functional.
> The problem: Engine will not start. When I applied some starting
> fluid to give it a little boost, it misfired back through the carbs
> and caused the starting fluid in the airbox to ignite. Scared the
> hell out of me. Got the fire put out in seconds, so I don't believe
> there is any damage to wiring, etc...
> Should I give up on dealing with the points and just buy the
> electronic ignition system off of ebay? Is it possible that the
> condensors (old, and one of the few parts I have not replaced) are
> causing this to happen? What should I check next?
> Thanks in advance,
> -Ash