Heald Super Bronc 8ph

#1
I just picked us a super bronc 8hp, not sure on the year.

Does anyone know what spark plug is recommended?

I had a Briggs and Straton vbe 796112 and a Champion RJ19LM, both plugs instantly fouled after running for maybe a minute on start up. Any advice?
 
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#5
I found the fuel adjust screw, it was out 2.5 turns, put it to 1.5 turns out, hopping the less fuel more air does it. Needle is at 2nd position from the top. The carb is a clone YW25, maybe I'll be running lean now, we'll see.
 

Minimichael

Well-Known Member
#7
And as another questionable source of info, I'll just add that turning in your mixture screw should reduce the air getting into your mix and I suspect will only increase the fuel to air ratio. Noting also that this would only be during idle thru early throttle.

Can we get wider shots of what your working with? Is that an open header? Do you know what size jets are installed in the carb?
 
#8
And as another questionable source of info, I'll just add that turning in your mixture screw should reduce the air getting into your mix and I suspect will only increase the fuel to air ratio. Noting also that this would only be during idle thru early throttle.

Can we get wider shots of what your working with? Is that an open header? Do you know what size jets are installed in the carb?
Thanks, I don't know the size of the jets, there's no marking on them. The screw I turned is on the fuel side of the carb, not the air side, so figured turning it in would be right to reduce fuel flow. I believe it's the stock exhaust. I just tried a new plug, it started for a second then died and no spark again. I wonder if it could be an issue with too much current to the plug?

I've called a local shop that works on these small engines to take a look at it.

I work on plenty of motorcycles, I've never worked on these types of engines before.

I also need to completely rewire this thing. I was hoping to add a battery, looking online, seems as these are not set up to charge a battery off the stator. It has lights and blinkers, I don't think the blinkers were ever wired in. I'd like to get it all hooked up. Did the headlight power right off the stator wiring or is there a AC to DC converter that should be on the bike?
 

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#9
If your power wires from the motor go to the battery and all loads are powered from the battery then the battery will charge albeit may be a very slow charge. I have a pile of Heald bikes and trikes. I will try to see if I can provide any good info. Just be patient as I don't get aroound to fast these days.
 
#10
Well I just looked at your pics and you have a fuse box on the side and looks like electric start. So if you still have an ignition key I would wire the battery to the key switch and continue the wiring from the on side of the switch to the rest of the bike. The fuses are probably for in-line protection of the electrical accessories.
 
#11
If your power wires from the motor go to the battery and all loads are powered from the battery then the battery will charge albeit may be a very slow charge. I have a pile of Heald bikes and trikes. I will try to see if I can provide any good info. Just be patient as I don't get aroound to fast these days.
Thanks for the help, it looks like the battery box is probably aftermarket. This bike doesn't have the electric start. Just trying to figure out the right way to wire it up.
 

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#14
Well I just looked at your pics and you have a fuse box on the side and looks like electric start. So if you still have an ignition key I would wire the battery to the key switch and continue the wiring from the on side of the switch to the rest of the bike. The fuses are probably for in-line protection of the electrical accessories.
There is no key switch. It also does not look like it has the original spot on the side of the bike for the key switch. Maybe the fuse box was an add on?
 
#15
If you go to the media section and scroll down to Heald, there is a crapload of pics of different set-ups. It won't help with your plug-fouling problem but it will help you become familiar with the Bronc line-up.
 
#16
Hello @Nick Felt ...welcome to the Oldminibikes.com forum.

Nice find for your first mini bike. We love us some Healds around here !

I've never seen a slide carburetor on a Heald, which leads me to ask about the governor.

Slide carburetors don't link to the governor, which can be a safety issue, unless you have a billet flywheel, and billet connecting rod, and have removed the governor's internal parts.

The reason being, the cast flywheels and connecting rods in these small engines will implode when revved higher rpms than what they are designed for. With no governor, over revving is too easy. Thus the need for billet flywheel, connecting rod, and removal of interior governor parts.

Does your hm-80 have billet flywheel and rod, and are the internal governor parts removed ?
 
#17
Hello @Nick Felt ...welcome to the Oldminibikes.com forum.

Nice find for your first mini bike. We love us some Healds around here !

I've never seen a slide carburetor on a Heald, which leads me to ask about the governor.

Slide carburetors don't link to the governor, which can be a safety issue, unless you have a billet flywheel, and billet connecting rod, and have removed the governor's internal parts.

The reason being, the cast flywheels and connecting rods in these small engines will implode when revved higher rpms than what they are designed for. With no governor, over revving is too easy. Thus the need for billet flywheel, connecting rod, and removal of interior governor parts.

Does your hm-80 have billet flywheel and rod, and are the internal governor parts removed ?
I'm not sure if it has the billet parts, I doubt it. I'm sure the governor is not hooked up. There is a small lever on the back side of the engine cover, not sure what it is. I can get a pic tomorrow.

Where can I get the correct carb and governor for it?
 
#18
I'm not sure if it has the billet parts, I doubt it. I'm sure the governor is not hooked up. There is a small lever on the back side of the engine cover, not sure what it is. I can get a pic tomorrow.

Where can I get the correct carb and governor for it?
Here are a couple of pictures I have of whats left of the governor and the engine serial number if that helps to identify what I need. Not exactly sure what I'm missing.
 

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