New to the forum with problem!

[czdiver]

I have a 1972 R60/5/6. My youngest son (34) has been ridding to work while his wife's Yukon is in the body shop. While coming home from work in the car pool lane the engine started to stutter, needless to say he got safely to the side of the road before it stopped running.
At this point the bike will start while on the center stand but set it on its wheels ( in neutral) and the engine quits.
The idiot lights stay lit the engine cranks and will fire but not stay running, ruff idle then quits like a fuel problem but Bings are getting fuel.

[dwerbil]

Hi and welcome to the forum. Have you checked to see if the fuel bowls have a proper level of fuel in them? Sounds like it could be a problem there maybe with a stuck float needle.
Once you have these Bings in good rebuilt order, they should run for several years without problems.

[SteveD]

This might be better in the Post 1970 airheads forum where more people will read it.

What carbs are on it? CV or slide?
When on the centre stand, will it start from off?
Simple things first.
Check for correct fuel flow.
Check bowls adequately filled.
Drop the jet stack and ensure the main jet is clear and the atomiser is clean. Take appropriate care in reinserting them.

[michael]

Might be something electrical?

[czdiver]

I have thought about checking grounds but I don't have a clue where to start!

[Duane Ausherman]

Welcome to the home. We won't let you down. If we don't know, we will make up something, or just degrade the thread.

Do you know about my website? w6rec.com

Start with the simple fast stuff first. Just pull off the fuel line to the carb on each side and open the petcock to check for proper flow. It should be 100 cc in about 15 seconds.

If that is OK, then do the items listed by others.

To save time, I always suggest using Google first. Just put in "bmw motorcycle /5 tuning" and see what you get. You might try to use other words than tuning, such as carb trouble or whatever is the issue.

You will find that 5-6 websites will have everything that you will need. Just bookmark them.

Please report back, as we like to know how things work out.

[Major Softie]

As I put earlier on your other post with this question:

Things that come to my mind that haven't been mentioned:

Big piece of crud in fuel line or pickup slowing fuel to a trickle:
First thing try switching to Reserve.
Second thing check fuel flow with line pulled off carb.
(this is now what Duane is referring to above)

Points not opening correctly (worn rub block) or something somehow got into points:
Check

Timing shifted due to loose fasteners or broken counterweight springs:
Check while checking points

[ME 109]

At this point the bike will start while on the center stand but set it on its wheels ( in neutral) and the engine quits.

Strange.
How repeatable is this phenomena? Is this a clue or a coincidence...........

[jagarra]

I am thinking it is a clue. it seems the problem follows weighting and unweighting of the chassis. I first thought it may be the wiring harness from the light bucket , but that doesn't move as all the movement is at the bottom the front forks. Can it be by the rear pivot for the swing arm, only thing back there that may effect running is where the negative battery terminal screws into the engine case, it's around there.

[Duane Ausherman]

Some bikes were miswired during assembly. I am going from memory and it isn't clear to me. Where the rear brake switch wires come down the tube, there is a round cutout on the swing arm bracket for the wire to be routed through.

That was the design and it is clear. The assembly people ran it another way and the wire could get pinched by the swing arm. That wire is hot and when shorted it can shut the motor off.

I wish that I were there to show you, as reading my own words, it isn't clear.

We rerouted many of them to fix the problem. Many showed damage and a few had shorted out already. Mostly we changed the wiring before it got smashed and shorted out. It may not have been your model, but after reading this thread, it came to me. I hope that helps.