Gas tank

Something that I puzzled over for a long time is the gas tank. What am I going to do for the gas tank? Then I found this in the back shop, it's a gas tank that is off of an old Briggs and Stratton lawn mower engine that isn't running. I looked like a good size for the bike so i took it. One problem is the fact that the carb was built into the gas tank. 

What I did to fix this problem is cut a metal plate to fit over the whole where the carb used to be. I used the gasket that was between the carb and tank to mark out the shape of the plate. I was also able to mark out the wholes for the screws this way. Once cut out I sanded the edges smooth, drilled wholes, and although I don't have a picture of it, I painted it gloss black.

Once the plate was done it was time to deal with the gas tank itself. First I stripped it of it's very old very bad paint job. For this I used a wire brush head on an angle grinder, this tool easily stripped the paint off the tank. Once stripped of paint there was another problem. I needed a spout on the bottom of the tank so gas could flow to the carb on the motor. My solution was to drill a whole in the bottom of the tank and use a strong adhesive called 'JB power weld' to secure a spout to the bottom of the tank. the JB weld worked like a charm holding the spout firmly.

Once the fuel delivery was dealt with I had to figure out my mounting system. I used lots of JB weld and some strong hose clamps to make the tank mountable. I used lots of JB weld to make sure the clamps would be secure enough to hold the tank after its been clamped to the frame.

Once all of the modifications were done with the tank, it was time for paint. So I used some masking tape to cover up all of the places I didn't want paint like in the tank so I covered the filler cap, and the area where the plate will go. Then I painted it with two coats of a nice new gloss black paint job that matches the plate. I looks really good now that it's done.

Carburetor

The carburetor is the part of the motor that accurately mixes the appropriate mixture of fuel and air and feeds it to the engine. All carburetors do this seemingly simple action, but it's not as simple as it sounds. Most carbs (carburetors) have several jets, valves and other small moving pieces all which must act in perfect harmony make this process possible. over time build up of crud and debris "clog" these small moving pieces making them not work properly. My carb although seemed to work ok it defiantly needed some care. 

So I took my carb off for a good and thorough cleaning and problems started as soon as I took it off the intake manifold. First the gasket materialized as soon as the carb came off so I had to take a special tool and scrape of the remaining gasket.

As you can see from the pictures the area where this gasket was cleaned up quite nicely. But all this left me without a gasket for the carburetor to the manifold. So I am going to have to make a new gasket. Making this gasket will be covered in a latter post.

Once apart the carb looked actually more simple than most other I have dealt with. For actually cleaning it what I do is take it in sections. because there are too many small pieces you can't really just take it all apart at once. What you do is take a needle valve or some other small part out take it apart, clean it then put it back together and reattach it to carb body. To clean it I can do several things, first I can spray it with a chemical the chemical is called carb cleaner. If this doesn't work I can gently clean parts by rubbing them with steel wool to almost sand of the crud.

If neither of these strategies works I leave the parts to soak in gas over night to loosen up the all of the build up. After it's soaking I will then go and use one of the previously mentioned strategies to remove the remaining crud.

When I was taking apart parts of the float bowl I came across this jet. It was so heavily corroded that typically I would have just gone and ordered a new one from  a local small engine shop. But they wouldn't carry parts for this carb. So I spent much time and effort to get the jet even close to being usable. And more time, effort and carb cleaner to get it to passably usable. I couldn't get it any cleaner so I said it was good enough and reinstalled the jet.

flywheel

When trying to service my motor for this project I wanted to fix my hack job fix on the ignition wire. When I found this motor the ignition wire was not there, well not complete. it looked like someone took wire cutters to it. I had the great idea to fix this I took some 12 gauge wire and soldered it to the ignition wire, then soldered that to another segment with a spark plug cap. This I thought was a sufficient fix for the time being but when this broke this spring I decided to do a proper fix for this problem.

To get to the root of the problem I had to take of the flywheel to expose the hidden ignition system. this is where the ignition wire originates. When I took the flywheel off I was very surprised to see how complex the ignition system for this engine was. The purpose of the ignition system is to provide  electricity to the spark plug so that it can detonate the fuel and air mixture in the combustion chamber. But in more common 4 stroke engines like this one the power stroke is every second rotation of the crankshaft. But because the rotation of the flywheel and crankshaft are in direct ratio the ignition system gets an electrical charge every rotation of the crankshaft. So this systems purpose is to only let charge to the spark plug every second rotation of the flywheel.

But my problem is finding a new wire to run from the ignition system to the spark plug. this isn't as simple as it sounds. Ignition wires run super high voltage, to make the spark jump in on the spark plug, this requires special kinds of wire. There are two kinds of ignition wire carbon wire which is what is the standard nowadays and high voltage copper wire which is what is on this motor. The high voltage copper wire hasn't been used in motors since the 50's which is the era that this motor is from. And because this type of wire was used so long ago they don't even stock it nowadays I can't find it anywhere. This was a problem but after much research I found a solution. Tube TV's, I discovered that tube TV's use a high voltage copper wire to send electricity to the bulb. So the plan right now is to find a Tube TV take this wire out of it and use it on my motor.