Flat Twin

Thanks Bob I hope you are enjoying the ride.

IT LIVES

I replaced the bad hall sensor a couple of days back and got the spark working again and it did run for about 15 seconds. That was encouraging so yesterday I had a couple of hours to work on getting it to fire and run again but no joy. It didn't even seem like it was trying to fire. I made an adapter that I attached to the flywheel taper so I could use my drill to spin the engine over and called it a day.
This morning I went out to the shop with the definite purpose of starting this engine today or else.
After a couple of hours trying I realized that I had lost most of my compression in both cylinders. I then took the heads, and cylinders off the engine for closer examination. I tested the valves again and touched them up a bit but found no problems there and the cylinders and liners were good also.
That leaves the pistons and o-rings as the only other source of the problem. The pistons were fine but the o-rings didn't look right. When I installed the o-rings on to the pistons they looked nice and smooth all the way around but now there were thick and thin spots in them. The o-rings were not holding there shape but instead had went to meet their maker.
I have been using the green o-rings from HF so I guess you get what you pay for. I found some that I had from a GM air conditioner rebuild kit and they worked fine. I reassembled the engine and grabbed the drill to spin it over but before two revolutions the engine was running. All that work just for the (enter expletive) o-rings.
The engine ran for several minutes and about 5 startups while I was adjusting the carb and then nothing. No spark again and the second hall sensor bit the dust. There are two 4-40 screws holding the sensor on the engine and they are very close to one of the traces on the board. They might be too close as the high voltage may be jumping over to the sensor and ending it's life. I have some KY-003 boards that have a hall sensor mounted on them so I soldered on some leads and hot glued it on to the motor without the bolts. We will see if that solves the problem or if I will have to move the sensor somewhere else away from the distributor.

I flipped it over one time by hand and she started right up so I let her run until she was out of gas.
Tomorrow will be tuning day and maybe a video.

Thanks for looking
Ray
 
Ray,
That is very cool. Love the workmanship. Must be exciting to go through all the development and details and then to see and hear it run.
Great job.
Patrick
 
Thank you all for following and liking my build.

Ray
 
AMAZING. And to think you built it without any real drawings. My hat is off to you sir.

Roger L
 
Wow, fantastic work!


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Well done! A brilliant piece of engineering
 
Great Job , you should be proud of that. It sounds a little like an old Harley and I mean that in a good way. It really has a cool sound to it . Its nice to see all of the moving parts with the top off also . Very fine looking and running engine , excellent workmanship. Thanks for sharing.
 
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