8 speed 79cc revival

xXNightRiderXx

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Ok, I got the wheel off the bike, and it turns out it's the pawls that broke. It freely turns to the rear, and catches to the front when turned by hand. I got the axle off, and need a 12mm allen wrench to remove it. I'll post a photo of the damage when I pull the thing off.
 
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xXNightRiderXx

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Jan 12, 2017
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Boise
Ok, I got the wheel off the bike, and it turns out it's the pawls that broke. It freely turns to the rear, and catches to the front when turned by hand. I got the axle off, and need a 12mm allen wrench to remove it. I'll post a photo of the damage when I pull the thing off.
I was wrong. It wasn't the freehub itself at all. It was the threads in the wheel itself holding the freehub to it.
IMG_20210718_225436~2.jpg

IMG_20210718_225346~2.jpg


Time to build myself a wheel that I can actually repair, instead of one that I have to replace every time something goes wrong.
 

xXNightRiderXx

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I found a double wall mtb rim with a welded joint and eyelets, a mtb hub with 6 pawls, no threads in the hub to strip out, and thanks to mbrebel, 12ga spokes measuring 254mm. Not only does this mean I'll be able to repair the thing when it fails, it also means that my bike can accelerate and stop faster because there's less mass to impart inertia to and remove it from. Who knows, I might even be able to go faster.

I think I'll also add a 203mm brake rotor to my rear wheel. Interestingly, my current system is 180mm with a 160mm is to post adapter, and it'll be 203 with a 180mm post to post adapter.

PS: this will be a 36 spoke setup, front and rear.
 
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xXNightRiderXx

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Ok, so here are my plans for the future:

Rebuild the battery box for more efficient use of space and better wire routing.
Port and polish, with another mild head sanding
Build new wheels
Build a tow trailer for my mtb
Craft an engine cover to block mechanical noise
Have a new exhaust pipe with a glass pack muffler made
Buy and install a one wire alternator
Buy and install the bored and reworked carb install from agk
Buy and install the agk flywheel
Buy and install a new spark plug for more efficient burn
Get a vin, insurance plan, and registration
Buy and install a longer intake for more low end power
Avoid losing my bike to inattentive or malicious drivers. (Ongoing)

I shall post photos as soon as each item is accomplished.
 

xXNightRiderXx

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I probably could have made this better. I'm the one who wrote it, and after all this time of not even thinking about it, I'm having a hard time deciphering it. So, I'm going to streamline my wiring representation once I've redone my wiring. And yes, I do need to redo it. It's a rats nest and barely fits into a 1" split loom.

Anyway, I'm going to get some tools and parts month after next, which is after I pay my legal fees. Gonna get those wheels built, and my cylinder head spiffed up. Gonna angle my valve seats, lap my valves, port and polish, and do some more sanding for more compression. Then I'm gonna install that flywheel, then take a center punch, and pop out that blasted governor. I'll be free and clear to do other mods after that. At some point, I may decide to do a cam upgrade and 22lb springs, but until then, it's on the back shelf. Has anyone ever spun these engines up above 8k for an extended period? Maybe close to 10k? If I do a shorter air intake and bigger cam, that's where I'll want to spin it up to. Between 6k and 9k. Alternatively, I'll keep the small cam and a long intake and keep the power around 3k. I would like to advance my cam timing just a few degrees. Any way I can do that without paying for a custom cam?
 
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xXNightRiderXx

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I found a company that has done custom cams for this engine: performancecams.com

$135 for a custom welded profile. What I'm thinking is offset timing, but maintaining the intake opening position and making the closing position a few degrees later, and maintaining exhaust duration, but moving open and close a few degrees later. The idea behind this is the later the intake stays open after bottom dead center, the more the intake velocity can be used to charge the cylinder, and the more compression I can get. The later the exhaust opens and closes, the more the exhaust can be pushed out and replaced with the intake charge. The intake will be opening just before the exhaust closes to take advantage of scavenging. If I'm mistaken, tell me straight up, and let me know about anything that would be better.
 

xXNightRiderXx

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Jan 12, 2017
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Alrighty! I got a class action payment which I used to purchase an alternator, two #35 20t sprockets, a pulley for the crankshaft, and a set of glass and alloy mirrors that won't shake as much as these damn plastic ones. They even have a much higher range of adjustment to get the perfect angle to properly see behind me.

I have the new hubs on the way, which have 6 pawls, and the teeth the pawls engage are on the hub itself. The freehub body pulls away from the hub, so there are no threads that can be stripped away. Next step: Rims and spokes, 93 octane stickers for the tank, carbide burrs and sanding spirals to do some port work, and a set of valve seat cutters for a 3 angle seat job. With the intake, I won't use the sanding spirals much. I'll just let the burrs run around the intake port (light pressure with the Dremel, no resistance against the rotation of the burr), lightly using the sanding spirals to remove any peaks obstructing the charge. This will produce a rough finish in the intake port to keep the charge atomized without reducing the amount of fuel and air entering the cylinder. Any objections to this method?

I'm also thinking of turning the engine around and using an idler sprocket system to reverse the jackshaft rotation. This will allow me to mount the engine level and get optimal cooling, leg clearance from the exhaust, and oil level. I will also be able to route the exhaust down and back, keeping it away from the saddle and my thigh. Not sure how easy that will be, however, I'm sure I can do it, since cars and cameras did it. I'll just be using nuts and bolts instead of welds.