Won't fire, even dies once hot... ideas?

[Snikare]

I have a fresh, full new build. I'm using the HHB PMA kit. Everything works just fine until things get nice and hot, then the motor will die. Once it dies, I have to wait for the motor to cool a bit and start up with the headlight off. At that point, I can just make it home from a short ride into town.
I have two thoughts. Either my capacitor or my regulator is over heating. Both are under the bike and should be getting plenty of air. The capacitor is in the space where my starter was, the reg/rec is under the swing arm. The last time I ran it, I was feeling things for temp and the reg/rec was smoking hot.
Should it be getting hot enough to burn your skin?
The container that the capacitor is in is vented and the cap is buffered from the side of the container, it gets warm, but not hot....

I'm running the HHB PMA with points and a Sparx capacitor.

Any thoughts would be appreciated!

 

[retiredgentleman]

How old are the ignition coils, and are they the stock OEM type?

 

[Snikare]

It's a brand new high output coil. Mounted under the carbs. It's not overly warm to the touch.

 

[retiredgentleman]

It's a brand new high output coil. Mounted under the carbs. It's not overly warm to the touch.

Well, that's a bad choice of location for a coil. The coil will receive heat transferred from the engine. I can't think of a worse location

Its always best to mount a coil as far from the engine heat source as possible. Airflow is also a benefit. Some coils get hotter than others, and need to have their iron core solidly bolted to the bikes frame to act as heat sink.

I use an Accel coil and I have it mounted in front of my engine, so it receives cool air as I ride.

How is your coil mounted?

If there's no room under your tank, you should mount the coil in front of the engine.

 

[Snikare]

That's a bummer to hear. I thought it would be okay there. The coil is mounted to a metal bracket that is connected to the motor mount. You should be able to see it in the picture. I don't have room anywhere else that wouldn't be blatantly seen. I'd like to keep it as hidden as possible. My peanut tank has no room under it. While feeling around as things were hot, the coil didn't feel warm. However the cam chain tensioner cap did. Maybe I could just put a heat insulator between the coil and the block. I'd like to keep from having to move it. I'm sure is not getting heat transferred through the mounting bracket, and I couldn't imagine it needing to be cooled any more by sinking heat from it through the mount, as its not really hot to the touch. But I could imagine it needing a diffusion from radiant heat coming up to it from the engine block. There's about 1/4" of space between the coil and the block. I'll fit some heat dispersing insulation mat onto the bottom side of the coil and see if that helps.

At one time the problem was worse, but the capacitor's housing didn't have holes in it. Once I drilled the holes in it and added an airfoil to direct air to it, it got better. But now the issue just takes longer to show itself. I'm kinda thinking I may have done some damage to the capacitors insulation. I'll probably replace it as a precautionary measure. However my main concern is how hot the reg/rec has gotten upon inspection. It was overly hot. My Honda's never got that hot. This shouldn't be normal right? Tomorrow I'll jump on it for a short ride and then take a temp reading of it.

 

[Snikare]

Actually, you can't see the coil mounting bracket in the last pic, so here is a new one.

 

[retiredgentleman]

It appears to me that the coil would get conduction heat from its mounting bracket, and radiation heat from the engine crankcase. You can make attempts to keep the coil in that location, but I think its a losing fight.

You can see in my picture how I mount my yellow Accel coil. Its gets nice cool air coming from the front.

I don't subscribe to the "hide components at all costs" way of thinking. Items such as ignition coils and rectifiers need to be kept from getting hot.

A capacitor should not be getting hot.Its a voltage device, and does not supply very much current at all.

I have no experience with PMAs. I prefer the stock type alternator and a 14 amp/hr battery, which has given me 100% reliability, and effortless electric starter motor starting for 8 years now. .

 

[Snikare]

Here's an update now that i've made some minor changes. The capacitor's housing is way more breathable, and I'm comfortable now with it. The regulator on this last test ride didn't seem so hot, but it was still pretty frickin' warm! I don't think that's really the culprit though.

I put a couple pieces of exhaust wrap folded up into a pad under the coil and thought it may at least show me if that would keep the coil running cooler. Then I did about a 5 mile ride. I rode with my fingers on the coil as much as possible to see if there was much of a temperature change on the outside of the coil, and although the area is full of warm air, the coil never seemed to get very warm at all.

Here's where it gets wierd though. At 5 miles in, a car pulled out in front of me, so I flipped on my headlight. As soon as my headlight came on, the bike died...! I pulled over to the side of the road, and tried to kick it over again. NOTHING. I waited and let it cool for some time, even had to end up pushing it home. Still nothing. Now the bike is totally cooled off. I am still trying to kick it over and getting nothing. Not even the LED taillight will light up. Usually the taillight lights up upon kicks. But I am getting nothing at all. Headlight is switched off. I'm pretty stumped now. Can't figure out what it might be. I'll end up replacing the capacitor just for good measure, as I think I've done damage to it in the past, but it had been running really nicely in the few earlier test rides. Previously I could kick the bike over in two kicks with the headlight on.

Any ideas? Your help , and thoughts are always apreeciated!

 

[retiredgentleman]

Again, I say I have no experience with a PMA.

However, you should not be riding with the headlight off. The PMA watts have to go somewhere, as it cannot cut back on its output as a stock type alternator can. Its best if some of the watts can go to the headlight, which makes for less watts that go to the regulator, which the regulator has to dissipate as heat.

You may be overloading the regulator's ability to shed heat, which also could mean the
voltage, as you drive down the road, is going much too high.

Using an LED taillight also works against you. With only small wattage used by the LED, again more wattage must be comsumed by the regulator.

Install a voltmeter on your bike so that you can see, while riding, what voltage you have on the bike.

My opinion.................get rid of that capacitor and install a decent size battery, and you won't be pushing your bike home anymore.

 

[Snikare]

Well. I wouldn't normally ride with the headlight off. But, like I mentioned in the previous post the bike died when i turned it on. It was showing signs of doing that early on, by having a hard start unless the light was switched off. So I turned the light off and rode with it that way to do a test ride. I thought that by turning it on while at higher RPM it would have done fine. However this last ride and the fact that it died has shown me that by turning the light on, it has suffered a failure somewhere. My interest is of course where that failure is, and there aren't many places that it would be coming from. I'm a bit lost though. I'm replacing the Capacitor, as soon as it arrives in the mail. The coil doesn't seem to be the problem as of now. the Regulator has been getting warm, but is in a good location and should be slacking off the voltage as heat. That should be it's job anyway... The switch is a normal 3 pole switch from LowBrow. Seems to work just fine. And the Headlight is a 50W halogen. That leaves me to think that the Capacitor is the last remaining thing to fail. And originally I had put it in an enclosed container. It was obviously getting too hot, and my finall fix has been to vent the container. Today I drilled a ton of holes in it to get more air in and through the container, and well as minimize the heat build up. It seems to have worked, except for the electrical failure. I'm hoping that it's just a hold over from the previous over heats, and the new one will solve my problems. But it seems odd that it would have a catastrophic failure when the light is turned on...
I can measure my voltage with my multi-meter while the bike is parked and running, but I would rather not install extra gadgets on the bike permanently. However at this time, I can't even get the bike started. So I'll have to wait to see if the new capacitor does the trick. Which in itself will be a huge tell-all.

 

[NONclow]

Bare metal ground connection fault on the rec/reg

When I replaced my reg and rec with the solid state one from mikes, I didn't get the ground terminal connected properly, and would make it about 8 miles before it would start to cut out. Flicked my HL switch off, ran great for another mile, then died, two miles from home. Fixed ground. Still running today.

FWIW my reg/rec is mounted under the seat, on an aluminum heat sink that spans the seat(old pic). Not tucked away.

 

[Snikare]

Great. Thanks for that. I'll look at my reg/rec ground immediately. I too once had mine on an aluminum plate under my seat and that may be why it seemed to have stayed cooler. That was another bike though too, and it was running lots of electrical. I may be able to add some sort of extra hårt sunk to how I have this one mounted here, or maybe add some kind of air foil to push more wind toward it.

Thanks again. I'll report back.

 

[Snikare]

I just checked my grounding for the Reg. It looks like it's solid. I have it attached to the engine block, and it registers through the multimeter with a strong signal.
Here is my schematic. There is a ground on the taillight that I have not drawn in. Just and FYI. Otherwise, it 's what I am working with.

 

[Snikare]

It ended up being the Regulator. I got a new reg in there plus a new stator, and it runs perfectly now. Will put some more miles on it and then give another update.