4hp briggs cruiser project

RocketJ

Member
Joined
Dec 2, 2017
Messages
109
We finally hit a break in the weather in upstate New York, so I took the opportunity to work on my btr/powerplus bike. This bike originally started out as a sportsman flyer with a cheap china girl slapped on, but I soon realized that it just wasn't doing the bike justice. I ripped out the old engine and accessories and started out on making this a proper 1915ish motor bicycle (with my own flair of course)

First task was to find a motor. I scowered the internet for cheap predators and generic 4 strokes before Curtisfox, a fellow member on this forum, contacted me about a beautiful 4hp briggs.
We swapped a few emails and i received the engine a few weeks later. I cleaned it up and gave it a test run. It works like a charm.

Next was to fix the problems on the bike. The frame and back wheel were horribly bent from an accident.

The frame was easy to rebend, but the back wheel was completely shot. I spent several days removing every spoke and the coaster brake system. Ultimately I decided on buying a new, but slightly smaller brake hub, boring every...single...spoke hole, rebending the spokes straight and relacing the spokes back into the rim.

From here on things went pretty straight forward. I attached the fenders, head light, rear axle kickstand, mounted the engine and started truing the back wheel.

I'll update this thread as I progress over the next few weeks. I hope to get the throttle linkage fixed and have a turn over of the engine by the end of the week.
 

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Will'smotobikes19

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Apr 9, 2018
Messages
1,653
Im thinking of doing a build with a 4hp lifan 118cc or gx120 maybe gx160. I created a post about it but no one has commented on my post. I want to get a billet flywheel, rod and mikuni for it and remove gov too. Apparently some people use the gx120 for racing go karts. Surely it will be faster than my stock 79cc. That can't go up a hill without pedaling.
 

RocketJ

Member
Joined
Dec 2, 2017
Messages
109
Im thinking of doing a build with a 4hp lifan 118cc or gx120 maybe gx160. I created a post about it but no one has commented on my post. I want to get a billet flywheel, rod and mikuni for it and remove gov too. Apparently some people use the gx120 for racing go karts. Surely it will be faster than my stock 79cc. That can't go up a hill without pedaling.
Good luck. It sounda like a plan.
 

RocketJ

Member
Joined
Dec 2, 2017
Messages
109
Update:
The weather cleared up a bit so i took the opportunity to work on the bike. I rebuilt a carb for it and got it running. For a 59' briggs, it runs extremely well. I also started work on the jackshaft. I'm not completely satisfied with how it came out though so some tweaking will have to be done. I plan on finishing the hand shifter as well later in the week.
 

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