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Old 02-12-2012, 12:30 AM
Motorized Bicycle Elite Member
Join Date: Jul 2010
Location: CA
Posts: 1,744
Default Re: what did you do to your motor bike today?

I tried out my Briggs 3hp that I reconditioned from a 70’s era 80202-0430 model that I had running about a year and a half ago. The valves and seat were cut to restore the proper angles for both. Great compression was gained by better seal on valves. Lapping at a point was no use as the angles began to match seat to valve.

Now that I have a lot of the bike ready and a newer carb than the vacujet I tried it out yesterday. The gravity feed carb with bowl and float works nice with the gas tank I have for lawn mower and made to fit on top bar. There are a multitude of adapters I made for the carb so that the bowl is level with the engine tilted back about 17 degrees, as well as a connection for a remote primer bulb, and an elbow bend manifold to avoid the seat down tube.

The carb does not include any choke or adjustments. Only I saw what looks to be a needle that is integral with the nut that goes in the bottom of the bowl to hold it on. It does not adjust. There is a very small indiscrete hole machined into the edge of the flange and gasket on the air intake of the carb.

I had no idea what it was for a long time till I found that the carb was for an engine that had the primer bulb attached to the air filter housing. I had no such filter so I made the adapter to tap into this connection. I used another defunct carb except for the primer bulb and mounted the modified old carb to get pressure down a hose to the tap I made to the new carb to do remote priming.

Initially I had a problem yesterday when a kill switch wire, which is also the same wire that goes to the points and the low tension at the magneto go bad. Other two wires on the magneto are the ground and high tension. They were OK, but there was a break in the solid wire that was going to the points cap contact. The insulation was there though and hid it broken inside.

Note I prior had a y connection just outside the point cover. This meant only 1 wire to goe through the hole with spring. I may revert to that again as extra wires that don't fit if fray leave a possible short from pieces that break off.

I didn’t have a meter, but made a bug light, and then realized I should have replaced all the wire with stranded. So I did that and I fired it up and ran almost great. I had a real hot spark but the point gap was not right so it could not attain highest revs.

Today I adjusted the point a little closer to be at the spec 0.020” as best I could. I had my calipers, but no feeler gauge. I used a hack saw and it was too wide. I guessed as best I could.

Today I forgot to get a new feeler gauge but made the gap smaller still using a piece of cardboard measured to be around 0.020".

It ran better, but still needs a slightly smaller gap and it will be fine. I think as I adjust the points again, I’ll also tin with solder, as I don’t think it is too hot in the point cover to melt, the stranded wires I used.

There less likely for the stranded wire to break, but any little ends not going through the connector with the springy connection to the cap point gap and it could short. Actually, I think instead of tinning, just a little of the high temp rtv over it to seal it over.

While I was testing it last time and this time, I had the recoil pull starter with its clutch doing the over-running thing. See this good video on YouTube on how to fix.

I had thought that I had heard that there is a mark on the square connection of the starter clutch, a pawl clutch that has to line up with the recoil matching part. Now after seeing the video I think it does not matter, the mark shaved edge may be for something but in mfg process only.

The video does not say anything about that. They do say if there is too much scratches and dent, then you have to replace the starter clutch. I’m hoping it is not that bad. Just degrease, emory cloth sand some surfaces, and relube.

Hate that eeeeeehhhh sound and the rope spitting back at me.


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Last edited by MEASURE TWICE; 02-12-2012 at 12:48 AM.
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