Building my first Harley one part at a time

[DustyDave]

If I did that would I not have to lap the cases and then line lap the main bearing hole and find the right sized race for it? Even not doing that may be better than what I have, but in the past matching two different cases has caused me nightmares I do not wish to revisit.

Decking a cylinder base with a huge lathe file was not fun. And finding out later on my tranny pissed ATF (2 stroke) all over the place as soon as it got hot was worse. I had to take it all back apart and use sandpaper on glass to get them close. Then make thinner shims for the output and lay shaft. After the fucker still leaked, but was not bad enough to make me do it again. ($150 Yamaha with a $1000 of my labor in it if I paid myself) That engine had MX 175 MX100 YZ 125 YT175 and IT 125 parts in it and became a short stroke 160-170 engine in a MX100 frame

Lapping on a surface plate, piece of granite or even a thick piece of glass with a sheet of wet or dry sandpaper stuck on top is usually successful I even used a tennis court directly on the concrete once, Fair warning some woman in a delightfully short skirt gave me the worst ass eating I ever had. The sign said it was a public park I measure all the height of several places around the perimeter with any proud spots off the edge and write the measurements where they were taken and adjust pressure toward straight as I go.
Dusty

[CaNaDiAnNuTcAsE]

Open primary clutch's only last 500 miles? Says who?

Not the clutch. The stock chain, but I'm thinking about turning down a set of primary sprockets and running an X ring with good chain wax now.

[CaNaDiAnNuTcAsE]

This is what I want to do, but I understand there are a few problems with it. So I'm only thinking about it now.

Don't get on me about this being dangerous I've done worse. I had a sled engine in a bike with the secondary almost up my ass so this don't concern me much.

[farmall]

You can soak a new (they're cheap enough) stock chain in liquid chain wax. Motorcyclists tend to forget the liquid stuff exists. The single row chain is more for kool than longevity. Sprocket blanks are not expensive though and turning off the old teeth then pressing on and tack welding new "rings" on is done all the time in repair machining.

No need to buy primary covers if going kick-only is a bonus. Machinists buy "machinable bore" sprockets (when you tack yours on don't anneal the teeth if ya can help it).

https://www.mcmaster.com/sprockts/

If going single row make more than one set of sprockets for obvious reasons and have spare stock parts ready to machine.

[CaNaDiAnNuTcAsE]

Fuck should have thought of welding on the sprocket. I've done it a few times before.

The trick for keeping temper is some good wet modeling clay over the teeth. That's something I learned from a welder in his 70s I learned alot from. Guy welded body panels into cars so good you could almost just paint over his work with no filler.

He also taught me lead filling. Almost blew myself up trying it later on a gas tank. And yes I water filled and drained it first.

[farmall]

Good to know modelling clay works as welders putty because it's less expensive.

Plumbing suppliers etc carry a variety.

https://www.nucalgon.com/products/sp...mo-trap-putty/

Some builder made not a dual row but dual single row chain a few years back.

Another used multiple industrial Kevlar V-belts which is fucking brilliant since they're redundant, lightweight, available and look kool as fuck. It was four sheaves IIRC.

[CaNaDiAnNuTcAsE]

Another way to keep heat local is to crank the heat on the welder. Seems counterintuitive, but you get in and out fast with excellent penetration and actually keep the part cooler.

Good rule of thumb: if your welder cant blow through the material it's too cold and your too slow. I generally keep the welder at a high temp and use feed and speed to keep it at the right temp.

Another trick if using a shit welder is to keep in mind heat is voltage and feed is amperage. If you keep blowing the breaker crank up the heat and slow down the feed.

As far as I know this is for MIG only.

Almost forgot the most important thing I ever learned about welding: adding material is not proper welding the strongest welds add the least amount of metal possible to fuse the existing steel together.

[thecarfarmer]

Not done processing, but here is link. It will be available by the time I get my shitty dinner cooked.

https://youtu.be/G3xZj36DSO4

Some good info here!

Had to Google "flyback diode" - looks like basically bridging a diode across a coil or solenoid. I've seen where something with a coil in it (IIRC it was some kind of relay) had a diode built in.

[CaNaDiAnNuTcAsE]

Ya its because all inductive devices store power. Once that power source cuts out the device will dump a reverse voltage spike at higher than input voltage at lower amperage. The diode will allow that voltage to be dumped as almost a direct short and save the original input device from the reverse voltage.

If you ever have electronics die right away and there's a inductive device in the circuit you should look at that first. I built an engraving chisel once that was blowing its mosfet right away and put one over the relay and solenoid, problem solved.

There's also situations in any AC systems where you get transient voltage spikes and you use zener diodes to fix them. They are similar to normal diodes, but in their case we use the reverse breakdown voltage to suppress the voltage. They can also be used to modify the output of a regulator IC by connecting to a ground pin to force it higher.
Example a 5v regulator and 4v breakdown zener gets you 9v output.

[thecarfarmer]

What about putting a cap between the + side of the inductor and ground? Accomplishing the same thing with a different component?

I think that's essentially what the condenser in a Kettering-type points ignition is... the points are switching a transformer coil on and off, and the capacitor ("condenser") is installed between the points and ground to bleed off that flyback current from the coil

Of course, there were no diodes when point ignition was invented... I guess the diode may be a better, more modern solution.

And the real question now, is could I get away from having to use a condenser on ignition with a flyback diode

Not to derail a quality thread...

[CaNaDiAnNuTcAsE]

While a cap helps with the voltage fluctuations it is not ideal. If the wattage of the reverse spike is greater than the loaded cap you will simply blow it if it's an electrolytic cap or if ceramic it will still allow the circuit to go reverse voltage.

The diode is taking that reverse voltage and dumping it immediately. With a cap you are slowly removing the inductive devices power source and the slow breakdown of EMF will cause the spike to be much weaker. However it is still there.

In the end in most situations a cap can be used, but in all situations a diode will work.

In all AC to DC conversions (like a stator though a rectifier) a cap is a good idea. You take those nasty irregular phases and smooth them out into clean voltage. If you ever power up an old amplifier and heard that shit 60hz hum a simple capacitor can eliminate that. Keep in mind electrolytic caps fade over time. (How that clean sounding amp got that hum to start with).

[CaNaDiAnNuTcAsE]

As for eliminating the condenser. Dont the EMF breakdown is modified by it and your bike will not run properly. You will also cook points and burn out plugs, especially resistor plugs.

Edit: the reason why is the higher inductive spike is causing electro discharge machining to the points and plugs. The faster discharge is changing your timing.

[farmall]

If one doesn't care for the cheap capacitors supplied with most points systems you can run ceramic caps instead.

One (very nice) aftermarket replacement for the old-style external Mallory 25010, 24895 etc is actually a machined brass tubular enclosure with a ceramic cap inside. IIRC Dragstews posted pics of it a few years back.

https://forums.aaca.org/topic/343708...is-7-too-high/ is interesting. Scroll down to the A.E.A Training Manual pics noting preferred capacitance for slow vs. high speeds/RPM.

Being lazy and having plenty of condensers I've not hunted down a ceramic replacement for HD points units (which can be located next to the coil as on Japanese bikes etc if desired) but that could be a nice upgrade.

[thecarfarmer]

@Canadian: yeah, was hoping that a simple (cheap, readily available) diode could replace the cap. And had kinda figured if this had occurred to me, it would've occurred to someone else...

@Farmall: Tony DeFeo (Uncle Tony's Garage on YouTube) has covered this plenty on his channel; good quality ignition components are getting scarce. Leaving all of us to scrabble for an ever-dwindling supply of NOS/NORS goodies.

Have always wondered why a guy couldn't just sub in a cap of the proper uF - had just kinda guessed that it took something that would handle a bunch of current, and there was a reason nobody was doing it

Turns out they ARE doing it, I just didn't know about it!

[DustyDave]

The condenser in the normal Kettering location not only absorbs the follow on current that any switch sees but also discharges back into the coil lengthening the spark duration. Across the coil won't work as well and on the positive side wont work at all. The Illinois Capacitor no. 224PPB102K is supposed to be a suitable substitute. On my 12 volt bikes n cars I unhook the capacitor and add a GM 4 pin Ignition module on a heat sink with a 1K pull up resistor. The current flow is so low wi9th this setup that points never wear out at the contactors the rubbing block wears away first. This picture shows the condenser still mounted but it must not be connected electrically. This setup works way better with a more modern low impedance coil from a bike with solid state ignition as the module can control the dwell better on a low impedance coil

Dusty