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Truenotch's 1974 Yamaha FS50 (FS1)


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14 minutes ago, HighLUX said:

How did you go about measuring squish?

By twisting up two bits of solder, laying them across the piston just below TDC, then bolting the head on and rocking the engine past TDC to squash the solder. 

Here’s mine:



It’s a good idea to measure your compression ratio at the same time so you don’t go overboard on compression... I made a little rig to CC my head and the dome of my piston... I’ve gone pretty far down the 2T rabbit hole now and might not come back. 

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My brand new kickstart lever turned up from the Netherlands. It was a very reasonable price (16 euro) but the shipping was not! (I don't want to mention the shipping cost). 

Nevertheless, it's super nice to be able to start this without going for a run.... 



I got itchy toes and wanted to experiment with the pipe some more, so I spent waaaay to long mucking around with this expensive spreadsheet. 


The calculations gave me quite a long chamber length and kept the standard header length... But man it was long. I had to pull the muffler up on a 45° angle to avoid a tripping hazard for pedestrians. 


Took it for a few hoons like that, found no real benefit to performance and decided I didn't like it, so I chopped the whole thing up again and put it back to the old setup: 


Good way to waste a couple of days :lol: . 

Hopefully my sprockets turn up from Yambits this week. I'm keen to see how far I can gear it up! 

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I still haven't cleaned this thing since the East Cape mission... Maybe that will happen this weekend? 

I got a special delivery from @Raizer today: a set of bars from a Vmoto Milan. They're about the height that I want and are quite narrow, which suits the FS1 reasonably well. I threw them on and took off the guards to see if I liked the look: 




I like the bars, but am definitely not sold on the no guards look... Especially in the rear. It would need to be a shitload lower and have a low seat to look right IMO. 

Put the rear guard back on and took a few other pics: 






And a couple of sneaky shots with the next 2 wheeled project... 



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