New electrics

[Luca]

I'm sure Monte knows the proper saying, but on airheads if you think it's electrical, check the carbs, if you think its the carbs, check the electrics.

To let fuel out of the bottom of the tank, you need to let air in the top.  The gas cap on the R65 holds this vent.  Try riding around the block, and when the bike starts to bog down, unscrew the gas cap.  If it is able to rev again, that would indicate a clogged tank vent, which can probably be shot through with solvent and compressed air.

If you balanced the carbs without taking the bike out for at least a 10 mile ride, they will probably need balancing again.  The bike needs to be fully warmed up.  It should still run, it just might be a little rough or have a high idle when warmed up

I can't stress enough that you should read the plugs, it is a very easy way to help determine if the carbs are parched or drowning.

A few other carb things:
-if you took the needles out of the slides, you need to make sure that they are set in the proper position.  They are adjustable and will substantially affect the mixture on the main jet.
-make sure that your choke cables have slack and that the choke levers on the carbs are fully returning.
-make sure you have no air leaks around the carb boots.

[Bob_W]

When the bike dies, if the throttle is shut off does the bike then idle or does it only idle after restarting?
When it dies, check for spark. If there is spark, the problem is then probably fuel.
Crank and ride until it sputters and then open the gas cap. This vents the tank.  When back in the barn, remove the carb bowls one at a time and measure the fuel flow. Snowbum says 350 CCs per minute are adequate. He also says both petcocks should flow 16oz in two minutes.
This should be a starting point in determining problem.
Float levels set too low could also lead to lack of fuel at speed. Torn diaphragm symptoms have been a lack of power in my experience.
Try to find the problem before throwing any more dollars at it. I always spend a lot of money without results when I try that solution.
Been there done that lost my shirt.
Bob

[tvrla]

Idle speed won't cause your problems, but I don't like idling them that high. I usually set it about 800 RPM. For the short amount of time my bikes idle, I can't imagine it being a problem, and so far in the 23 years I've ridden airheads, it hasn't been.

Also, I've noticed that a high idle somehow makes shifting more difficult. I have no explanation why that should be since the RPMs never drop that low when shifting, but it does seem to be the case.

In your case it doesn't sound like checking for spark will work, since the bike always starts back up. Checking for spark will tell you nothing.

Here's my thought - you said this problem didn't happen till you installed the new charging system. So why not replace the old components and see if the problem vanishes? Maybe it has something to do with the installation - a wire got pinched and doesn't short out till it gets hot - or who knows? But go back to the configuration before the problem and see what happens.

You need data to unravel this mystery. A scientific approach is needed to collect the data - eyes, ears, multi meter, experiments... however you do it, more relevant data is needed.

[Tony Smith]

The old Bosch coil...

...commonly known as the Crack-O-Matic.

I have replaced mine with a coil pack from a mercury outboard, for heat sinking purposes I've mounted it on a lump of 3*1" box section (until I can get to the metal recyclers and buy a suitable piece of aluminum)

[Luca]

In your case it doesn't sound like checking for spark will work, since the bike always starts back up. Checking for spark will tell you nothing.

I fixed up a nighthawk that had a poor battery.  It would start and idle fine, but when you started to rev it under load, before the alternator was producing enough juice to run the ignition, it would bog down.  You get more compression in the cylinder as you open the throttle, because you are letting more air into the cylinder, and you need a stronger spark as compression rises, which the battery could not provide.  I think it's still worthwhile to check for a strong spark when the bike quits, especially if you suspect that there is a problem with the electrical system (intermittent short from a pinched wire).

[decorn33]

So I set out to work through my list:
Pulled off the tank, removed the petcock, cleaned out some sediment I found around the base of the screen and put it all back.
Removed the in-line fuel filter and replaced it with a length of regular fuel line
Pulled the tops from both carbs and checked for problems with the new diaphragms. They were both seated properly and looked good.
Pulled the bowls on both carbs, and confirmed that I had equal fuel in each.  Opened the petcock and confirmed flow into each bowl.  
Pulled off each carb and confirmed that the jets were not clogged and the slides operated smoothly.
Put it all back together then unscrewed each plug in turn double checked the gap and grounded it against the head. Good spark found at each plug and they were both grayish white - so not too rich.
I ran the engine again until the stall occurred - again. So I had fuel, and I had spark, but the engine would not rev.
So I did the only other thing I could think of. I took out the new Alpha ignition - again, and this time the sender can also, and replaced them with the original Bosch components (which BTW, were working fine when I took them out - they're just old). The engine runs fine now. I don’t know why. Oh well. it's only been since August, and it's 16 degrees out now,considering wind chill. Since I have all winter, I think I’m going to ask Rick Jones to have the Alpha parts bench tested.

[montmil]

It's my understanding that Rick has replaced, free of charge, a few Alpha systems that had problems. Call him. He wants you to be happy with anything and everything he sells.

[decorn33]

I know - nothing against Rick at all. He had already sent me another ignition module free of charge to test out. It didn't help, so I sent it back. Good guy, but I still want to end up with new ignition that works, and I don't understand why the sending can would have anything to do with the stalling out problem - but it looks like it did somehow.

[Luca]

It could be a heat related problem, like Wirespokes had mentioned.  It's possible to slightly pinch a wire, and when the engine heats up and the metal expands, the pinch gets stronger and causes a short.

Are there any electronic bits in the sending can?  Maybe it is overheating.  Electronics don't like excessive heat...  computer components come to mind, as does the airhead ignition control module.  I even had an old cd player boombox that would stop working in the summer sun.