Bike won't start...

[OscarMayer]

HI:

I have a 1973½ R75/5. Last weekend I went for a Sunday ride for several hours. Stopping but never allowing the bike to sit long enough to completely cool. The bike had no trouble starting via the electric starter.

On Monday morning I got on the bike to go to work and it just turned over and over and over, but never gave even a slight cough.

I took my truck to work.

Tuesday night after disassembling, cleaning and reassembling both Bings I had my brother help me push start it in 2nd gear and we got it running... which made me feel a bit better about my whole ordeal, but it still doesn't start when kicking it nor when activating the electronic starter. I've charged the battery and made sure all the fuel lines, filters and petcocks are functioning correctly.

I'm wondering in what order should I test and replace parts to diagnos my problem(s).

Thanks in advance.

[ebeeby]

what color were the plugs? How does the spark look? How old are the points?

[Bill Burke]

1. I would clean and re-gap the plugs, then try it.
2. Then I would check the valve clearances, and re-set if off, then try it.
3. Then I would hone in on the battery. It might not be holding a full charge.
4. Then I would turn to the points experts. (I have a Dyna III).
Hang in there. The solution is coming.

[crazydrummerdude]

I'd:
1) Check spark, clean plugs
2) Check compression while I'm there
3) Check battery and starter relay
4) Check connections and lube 'em

If this doen't give an idea of what's wrong, I'd:

5) Check the points
6) Check the valves

I think this would be enough to narrow down the problem. It might be as easy as a battery (that was the major problem last time mine wouldn't start, but it would turn over. Even though mine seemed to be fully charged, it was what I would call "fried," but I replaced it and off I went.) or relay.. or not.

But since you were able to pop-start it and ride it, I'm thinking it might just be something simple.

[flash412]

Replace the plug caps with NGK. Those tired old metal Beru caps sucked during their first decade of use.

[OscarMayer]

what color were the plugs? How does the spark look? How old are the points?

The plugs seem to indicate that my bike was running a bit lean until it stopped starting. When I pulled the plugs and grounded 'em on the engine to investigate the spark they were definitely sparking, but it wasn't a thick blue spark necessarily. I hadn't done this when the bike was running properly though, so I'm not sure what a "good" spark would look like.

I pulled the front cover and noticed that the weights on the advance mechanism seem to stick a bit when I opened them with my fingers. The felt was dry. I'm guessing this would be why my bike was running a little rough before, but not sure this would have affected my ability to start the bike since it advances at higher rpm not when starting. Forgive me if that sounds ignorant.

1. I would clean and re-gap the plugs, then try it.
2. Then I would check the valve clearances, and re-set if off, then try it.
3. Then I would hone in on the battery. It might not be holding a full charge.
4. Then I would turn to the points experts. (I have a Dyna III).
Hang in there. The solution is coming.

I've been considering going to electronic timing. Did you put in the Dyna III yourself? How difficult is the conversion? Any reason for not converting?

I think I'll start by swapping out the platinum plugs for standard bosch plugs, properly gapped and get new wires and caps. The ones I got now are NGK, but I have no idea how old they are.

I'll reply to reveal my outcome after giving some of the other suggestions a try as well, including valve clearance and a battery swap.

Thanks.

[Bill Burke]

I've been considering going to electronic timing. Did you put in the Dyna III yourself? How difficult is the conversion? Any reason for not converting?

My used bike came with the Dyna, but I have assisted in the installation of a new one on another airhead. Here are the instructions, click on D35-1:

http://www.dynaonline.com/english/guides.htm

As with anything new, it'll make reasonable sense once you have the few parts to examine. Pretty straightforward, but it can be handy to have two people (one to watch the timing light, one to twist the sensor around). I'm a fan. And I know another guy who has replaced his failed Dyna with another Dyna. The failure rate appears low - it's a proven alternative to points. Which brings us to it's principle drawback: when and if the Dyna does fail, you are without the points system to fall back on. Potential to leave you stranded. Mine performed flawlessly on a recent 3k mile trip.

Keep at it. I'm a fan of NGK caps and plugs, but Bosch is fine. Make sure you get the 5K ohm resistance caps. It might just be the battery.

[OscarMayer]

Hello again.

Bike still doesn't start using the electric start nor kick starter. I haven't tried push starting it recently since I've been working on it alone.

I've done the following:
1. Regapped the plugs
2. Adjusted the valves
3. Swapped in another battery
4. Replaced the points and set the gap on them
5. Replaced the condenser
6. Cleaned the air filter
7. Rebuilt the carbs

I'm wondering if I should pull the heads and check for signs of seizing or valve damage?

Should I look to the starter relay? Would the starter relay affect the ability to kick start the bike? Is there a relay that can be purchased at Napa or Kragen, etc?

Should I look to see if the coils are bad? How do I test them? Would I still get a spark if they were bad?

Keep in mind that I do get a spark at the plugs. The engine has compression, but I haven't measured it 'cause I don't have the tools to do that.

Any advice is greatly appreciated.

:(

[jdmetzger]

Hello again.

Bike still doesn't start using the electric start nor kick starter. I haven't tried push starting it recently since I've been working on it alone.

I've done the following:
1. Regapped the plugs
2. Adjusted the valves
3. Swapped in another battery
4. Replaced the points and set the gap on them
5. Replaced the condenser
6. Cleaned the air filter
7. Rebuilt the carbs

I'm wondering if I should pull the heads and check for signs of seizing or valve damage?

Should I look to the starter relay? Would the starter relay affect the ability to kick start the bike? Is there a relay that can be purchased at Napa or Kragen, etc?

Should I look to see if the coils are bad? How do I test them? Would I still get a spark if they were bad?

Keep in mind that I do get a spark at the plugs. The engine has compression, but I haven't measured it 'cause I don't have the tools to do that.

Any advice is greatly appreciated.

:(

OK, we'll get this figured out, I'm sure!

First, if you hit the starter button and the bike is turning over but not starting, the relay is still fine. If you're getting nothing at all, the relay is bad (kick starter should still function) or you have another electrical issue.

You can still get a spark from a failing coil; probably a weak/intermittent one.

One quick way to test for any level of compression; pull out the spark plug, and put a small piece of paper towel/shop rag in the hole; not too far in, though! Hit the starter. The compression should be adequate to push the towel/rag out of the hole. Make sure to keep the plug grounded to the heads when you do this, so as not to damage the coils.

If you have compression, great!

After that, I would put the plug back in (clean and dry) and try starting it a few times. Then pull out the plug. If you're getting fuel, the plug is going to come out wet/gas smelling. If so, that's also a good sign, and we've narrowed it down to an electrical/timing issue, most likely.

If I'm wrong, someone else will surely correct me. If you get this far, post back with the results and we can get into testing the coils.

Good luck!

[OscarMayer]

Thanks Josh:

I had a bit of a brain fart. Today I went back to the shop with a new train of thought due to your mentioning that I should check my spark plugs and make sure they are "wet" after attempting to start the bike a few times.

I remembered that after replacing the above mentioned parts and looking at my plugs they were in fact not "wet."

So today at the shop my first thing to check was the float bowls. They were bone dry.

It seems that I was a bit low on fuel. As soon as I flipped the petcoks to reserve and activated the chock/enricher the bike fired right up.

Seems the problem all along was my points and or condenser. And then low fuel.

Thanks again.

OM.

[Bill Burke]

F.A.S.T.
Fuel
Air
Spark
Timing

So it was the fuel. Glad to hear you're up and running again. Sometimes it's hard to see the forest for the trees....

[manicmechanic]

I'm betting you won't ever do that again! Not that none of us never have, either. Glad it all worked out for you.

[PHMarvin]

That's almost as bad as grinding away with the starter, wondering why it won't start since it started with no trouble the last time, looking down and finding that "someone" had turned the kill switch to the off position!

[willtraubel]

New bike (to me), first BMW...first ride, Sunday morning..... set the petcocks to main tank (or so I think)...ride a bit, bike sputters, flip to reserve, so I think.... ever try to get a ride on Sunday morning whilst wearing full leathers?

Ask me if I now know which direction the lever points when on main tank...

It's nice when the solution is simple..

[Bill Burke]

Fear not Will. It won't be your last time. Since I shut my fuel down every stop, there are still occasions (i.e. gorgeous woman walks by just as you're mounting the machine for takeoff) when I find myself sputtering ....:)

[Polarbear]

I know this sounds mean spirited, but I was told this so many times in my early life and it sticks to so many of our problems, it seems. 35 years on Beemers has me convinced the slogan has merit. I have almost "Always" found the simplist fault with my Old Beemers, when mixed with a stupid human companion up topside! I have found myself looking at my bike so hard, trying to figure out just what was causing a miss, a noise somewhere, etcetc..to find eventually something I had forgotten to do, or overlooked. We've all been there, I think, so don't take it to heart, when you feel slightly retarded. My Airhead days have revealed to me that it is always the gas/carbs first, air second and electrics last. Not always in that order, but likely! Happy Trails, Randy

[mrich12000]

:type
It was a fine day to fly out af Dalas. Me and my copolit were busy doing the maifest check, and pre-flight weight schedule for the destination alottment.
pushed back form the gate, set of for tango wait do the pre thrust and runnup.
off we go, clearence to 37,500 East. desination Dade Florida.With time off there and a rotation.

The flight was the same nothing wrong untill we were out side of Pensacola.Fla setting up to desend to the local circuit,and make the run down the coast, set the craft to 186 dgs to the Dade localizer we abtian the inbound clearence to 18r
@ 20 miles out we start the run at 360knots we puform the safety list check, it's ok, then the internal check list on the Boing 737 during this test we find that the right landing light prove-out won't show green.`Well Don checked the reset's on the overhead panel and I checked the circuit breakers Just then the cockpit alarm voice sounded pull up,pull up.(THE NTSB REPORTED THE CAUSE OF THE CRASH WAS PILOT ERROR DUE TO THE PILOT NOT CHECKING HIS FUEL PETCOCK THE PLANE HAD CRASHED INTO THE SWAMP BY HIWAY A1A):buds :buds
:bottle :bottle
Michael Richard Pl.
VE3CEH

[woodgrain]

That's never, ever happened to me. That's my story and I'm sticking to it.

Woodgrain:brow

[trander]

Several years ago I owned a 500cc Velocette. I spent about half an hour one day trying to kick start it when my ex walks by and says, "is it out of gas maybe"? I said "of course not, do you think I'm stupid"? When she left I checked the gas and guess what?

[37071]

Happened to me in the middle of a crowded parking lot at a rally. I was riding my PD with the 9gal tank. The battery was low before I figured out the problem. Big tank or small it still has to have gas in it.