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ran when parked

E

edzr60

New member
Hello,
I am working on a friends 1971 R50/5. It sat for 3 years. The mileage is unknown. It's the old "ran when parked" story. So I have never heard it run. I have performed the following:
points, condenser, plugs and plug wires, all fluids, new positive and negative battery cables, rebuilt carbs, new battery, and I cleaned up electrical connections and adjusted the valves.
It won't start. I have a nice blue spark, and fresh fuel. It has only 70 psi. compression on both sides. I know this is really bad, but I have had other bikes that ran with less (not BMW's).
Your thoughts? Thanks in advance.
 
Last edited:
+1 on the valves; but for me, I wonder how you timed it??? Yes, you would have to static time it and it's best do using at the minimum a bulb that you can hook up to the points hot side and ground.........For me, I use an ohm meter; but no matter what, the timing could be off just enough to get a spark but at the wrong place on the timing sequence. ............Dont touch the carbs but have you checked the fuel level in the bowl???
 
Spark...fuel...compression. You indicate that it is low compression...that could be the valve clearances. You have spark...but as mentioned at the right time? And fuel. Is there fuel in the float bowls? Have you tried using the choke/enrichener system? It might need a little help when trying to start cold.
 
Thanks

Thanks for the input. I am sure the valves are adjusted correctly. I timed it with a test light connected to the condenser and the "S" mark in the middle of the window. I'm not sure what you mean about an enrichener. I just have the plungers that flood the float bowl.
 
So it's a 1971 R50/5...you wrote R50/2. At any rate, I forgot you have the slide carbs which have ticklers like the earlier /2s. How do you use the ticklers when you try to start the bike?
 
20774 said:
So it's a 1971 R50/5...you wrote R50/2. At any rate, I forgot you have the slide carbs which have ticklers like the earlier /2s. How do you use the ticklers when you try to start the bike?
Click to expand...

I hold them down until gas leaks out.
 
20774 said:
So it's a 1971 R50/5...you wrote R50/2. At any rate, I forgot you have the slide carbs which have ticklers like the earlier /2s. How do you use the ticklers when you try to start the bike?
Click to expand...

Yes, sorry it's a /5. nice catch
 
edzr60 said:
I hold them down until gas leaks out.
Click to expand...

That's not the way to use it. You're basically flooding it and hardly any engine will start like that. The tickler does depress the float to allow gas to flow into the float bowl. But you want to stop short of having gas drip out on the ground. I recommend that you begin holding down the tickler button for only short periods of time. I'd try holding it down for a count of say 3 or 4. Then try your starter. If the engine doesn't want to catch, try the tickler for another count of 1 maybe 2. I think somewhere between holding it down 3 to 6 times should be the right spot. Gas dripping on the ground is too much IMO.

It's a delicate balance...I "fight" this on my two vintage bikes that only have a kick start. You are trying to find the balance between dry float bowls and gas on your feet!
 
I have exactly the same bike. Like what was already suggested you are flooded. Pull the spark plugs, ground the wires to avoid sparks and spin the engine to clear the fuel. Try again with less tickle! Or no tickle.

Was the throttle wide open when checking compression?
 
20774 said:
That's not the way to use it. You're basically flooding it and hardly any engine will start like that. The tickler does depress the float to allow gas to flow into the float bowl. But you want to stop short of having gas drip out on the ground. I recommend that you begin holding down the tickler button for only short periods of time. I'd try holding it down for a count of say 3 or 4. Then try your starter. If the engine doesn't want to catch, try the tickler for another count of 1 maybe 2. I think somewhere between holding it down 3 to 6 times should be the right spot. Gas dripping on the ground is too much IMO.

It's a delicate balance...I "fight" this on my two vintage bikes that only have a kick start. You are trying to find the balance between dry float bowls and gas on your feet!
Click to expand...

I hesitate to offer this but...what worked on my Gold Star was to tickle it until gas flowed, give it a few kicks without any throttle, then if it didn't at least pop, kick a few times with the throttle held wide open. That usually worked. Of course the last day I rode it before selling it, it started first kick and then continued to do do by the second kick all day. It had never ever done that before. It was 96 that day.
 
ccolwell -

I certainly agree with your comment, although I'm not a fan of having gas pouring out the side of the carb. On my R69S and R25/2, I do my tickle routine and then kick through maybe 5-6 times. This serves to pull the air-gas mixture into the combustion chamber. Then I use the kicker to move the engine around until I feel the compression stroke. Then with throttle cracked no more than 1/4, give it a swift kick. Maybe 7 out of 10 times, I'm successful but I have to be ready to stab at the ticklers and work the throttle. If it doesn't start and I've reached the possible situation where I might have flooded it, I roll the throttle wide open and kick through maybe half a dozen times to pull fresh air into the chamber. That usually helps. If that still doesn't work, I remove a spark plug, kick through to expel the mixture and try again.

With the R50/5, typically people just use the electrical starter. But with the added kick start, one could incorporate some of the above to "prime" the engine before hitting the start button.
 
daz said:
I have exactly the same bike. Like what was already suggested you are flooded. Pull the spark plugs, ground the wires to avoid sparks and spin the engine to clear the fuel. Try again with less tickle! Or no tickle.

Was the throttle wide open when checking compression?
Click to expand...

Yes, throttle was wide open during compression test.
 
On a couple of old Triumphs (one mine, others friends'), releasing the tickler just a moment after gas flowed out seemed to be right... Considering the state of "technology" of their carbs and ignitions, it was important to not flood it or sprain your ankle.

Might the low compression be because the valves were set with the crank mark at TDC for the "wrong" cylinder... twice...?
 
edzr60 said:
Hello,
I am working on a friends 1971 R50/5. It sat for 3 years. The mileage is unknown. It's the old "ran when parked" story. So I have never heard it run. I have performed the following:
points, condenser, plugs and plug wires, all fluids, new positive and negative battery cables, rebuilt carbs, new battery, and I cleaned up electrical connections and adjusted the valves.
It won't start. I have a nice blue spark, and fresh fuel. It has only 70 psi. compression on both sides. I know this is really bad, but I have had other bikes that ran with less (not BMW's).
Your thoughts? Thanks in advance.
Click to expand...

If it has the stock Bing Slide carbs, I'm assuming you had them set at WOT before doing the compression test?
 
Pauls1150 said:
On a couple of old Triumphs (one mine, others friends'), releasing the tickler just a moment after gas flowed out seemed to be right... Considering the state of "technology" of their carbs and ignitions, it was important to not flood it or sprain your ankle.

Might the low compression be because the valves were set with the crank mark at TDC for the "wrong" cylinder... twice...?
Click to expand...

I remember my old Triumph. Everywhere I went my hands smelled like gas. I've had 7 airheads in the last 40 years so I'm aware of the danger of setting the wrong side. In fact, one side was set incorrectly on this bike by the PO. I vaguely remember a service manual out there that did not inform the reader to rotate the motor to set the other side.
 
Depending on how the bike was put away, it's possible that you may have stuck rings causing the low compression. Noting that this is a boxer engine with horizontal cylinders, it is still possible to squirt some oil through the spark plug holes, spin the engine a couple times, then check if the compression values change. Or if you feel really comfortable, put the bike on its side to add the oil. Might be worth a shot. Then if the compression does improve, maybe the bike will start and the rings will free up after the engine gets some heat in it. My experience has shown that engines with compression less than 100psig are very hard to start, so check everything else first before trying this method. It will get smoky if it starts.
 
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