Help ! Right Plug not firing.

[germanbike]

I have a 1960 (61?) R69.It starts right up,but the right side spark-plug is not firing.I am going thru service books,now,But is this a common problem?Any ideas?(I just put 2 new plugs in,same problem.
thank you,
mark smith
grants pass,oregon

 

[kbasa]

I have a 1960 (61?) R69.It starts right up,but the right side spark-plug is not firing.I am going thru service books,now,But is this a common problem?Any ideas?(I just put 2 new plugs in,same problem.
thank you,
mark smith
grants pass,oregon

Have you tried switching the plug wires to the other side? Completely, I mean. If the fault moves to the left side, you'll know you have a bad plug wire.

 

[darrylri]

If the plug is not firing on one side only, it should be pretty easy to trace it. Swap the plugs and see if the problem moves. If it doesn't, take the front cover off and swap the terminals that the plug wires are in. If it still doesn't move, then probably your coil is bad.

You should make sure that the the spark safety gap is set correctly, as well. There are two metal fingers below the coil, and each should be 10-11mm away from the tip of the spark plug wire where it's clamped in the coil terminal. If one of them is too close, the coil may be sparking there instead of at the plug. If this is happening, you'll know it immediately when you fire up the engine in the garage, with the front cover off. It's a great show!

You should also check to see what kind of spark plug caps you have. These bikes originally came with zero resistance caps, but they're hard to find these days. The magneto coil doesn't like extra resistance, so it's worth the effort to find the right ones. Craig "Vech" Vechorik has the right ones if you need them. He can also provide you a coil if you need that.

 

[20774]

When was the last time the bike ran? What maintenance have you been doing? On my R69S, there's a spark gap on the magneto that needs to be set right...10mm I believe is the setting. Not sure if the same applies to the R69. What about the carbs and floats? Maybe the one side is totally flooded and won't run.

Kurt in S.A.

 

[germanbike]

missing on the right

Thanks for all the help guys !,Let me get to work,and see what I can find.I just bought the bike yesterday.It has been sitting a long time,and started occasionally.The gas is fresh.It Idles(A bit low) and starts right up.(2nd kick this morning)

I'll cross the wires first.

mark

 

[darrylri]

Do you actually know that it's the plug that's not firing? There are a number of other potential problems if it's not the plug.

 

[germanbike]

R69

ok,
I am getting spark on the right side,but not as strong as the left side.The points look good,I have not checked gap yet.This is the first time I have worked on a BMW motorcycle but I have worked on lots of old german cars.

 

[darrylri]

One problem with the /2 points is that it's possible to get pretty bad differential timing to the cylinders. If you point a timing light at the little port on the left side of the flywheel housing while it's idling, you should see the S mark line up in the window. However, if the points cam is worn unevenly, which is not too uncommon, then the S will jump around. If it's more than about a 1/4" offset, it can start to affect how the bike runs.

It could also be that the valves aren't set right, which would be a good thing to try regardless. (And then you can move on to setting up the carbs.)

 

[germanbike]

R69

I changed the plug wires.It is the same.So I changed them back.The wires are "Packard USA" and the ends are "Japan"
These need to be changed !

mark

 

[darrylri]

If you get new wires, be sure to get real copper-core wires. The mag will not fire over carbon-core wires, and besides, there's nothing there to clamp into the coil's terminals.

 

[germanbike]

long reach plugs ?

should my R69 have long reach spark plugs? The ones in it are short reach 1/2" ? would this make a difference?

Mark

 

[germanbike]

R69

Thanks For all this info Darryl !
I will set the valves.I think this problem really is on the right side only.
The spark plug on the left looks fine,the right one is WET..............
I just cleaned the points.no difference.This bike was restored years ago and has been maintained by the BMW dealer in Eugene Or.It hasn't been riding many miles in the last 35 years,but always garaged and pampered.

Just to give you some insight on the bikes condition....

Mark

 

[darrylri]

If your bike should have long reach plugs, the heads will have the letters LK (lange kerze) cast into them right next to the spark plug hole. The bikes from 1961 wouldn't have had long reach plugs, but after 1967, those were the only kind available. Your bike could have one of each, for example.

If your plug is wet, then it's flooded. You could have a sunk float, or the float may not be sealing the float bowl. There are two forms of float bowl covers -- the original style where the fuel line comes in at the center and the tickler knob is metal, or the "lever top" style, where the fuel line comes in offset and the knob is plastic.

In either case, there may be some dirt or crud hanging up the float, but in the original style the float needle serves also to seal the bowl. The lever top style has a separate piece that does the sealing, with a rubber tip. The original style can some times be repaired by lapping the needle seat and needle with a bit of valve lapping compound -- be sure to clean it thoroughly if you do this. Parts are available from Bing Agency in KS someplace.

 

[20774]

should my R69 have long reach spark plugs? The ones in it are short reach 1/2" ? would this make a difference?

Mark

I see Darryl beat me to the punch... I believe heads that have "LK" embossed above the plug hole are long reach (3/4") plugs. Otherwise it should be short reach. I have the LK heads for my R69S off the bike. I measured the amount of threads in the head...it's about 0.7 inches. So, I would imagine that the short reach plug thread depth is going to be small amount under 0.5 inches. You should be able to look at the heads and tell.

Kurt in S.A.

 

[germanbike]

'61 R69

OK,
I cant see a LK on the heads.I did pull the float on the right side earlier.It didn't have fuel in it,all looked fine.
I just took another test ride,I am getting some "clearing" but its when I give it gas and let off,right at that moment it seems to run smooth for a couple seconds?
I do have the carbs with the plastic primer button on top.
valve lash is correct so is point gap.

I am dying to ride this new toy running correctly..........

M

 

[darrylri]

It really sounds like the float in the right carb isn't sealing the incoming fuel. Does the carb leak gas onto the ground sometimes when the petcock is left open? Try starting the bike and then closing off the petcock for a few seconds; when the motor starts to speed up, open it again. Does the right cylinder run during that time?

 

[germanbike]

R69 Fixed !

OK

I pulled the right carb,took it all apart,and found that the Idle Jet was clogged.cleaned everything,put it back together and she now Purrs.......
I just took my first real ride on a vintage BMW !

I'm ruined for life...............

thanks everyone !! I got to go ride my machine.

Mark

 

[germanbike]

R69 Pic

Heres a picture of my bike :
Mark

 

[germanbike]

'61 R69

pic 2

 

[darrylri]

Saaa-weeeet!