Modern Vespa

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SOoo, I was running WOT, about to kill for a plug chop, when the engine sort of bogged/ revved/ stalled. I grabbed the clutch and coasted to a stop. First thought was- soft seize. She would start, but would idle and bog and die the minute I applied throttle, and was spitting gas out of the throat of the carb. Pushed her 1.7 miles (to the 1/10) to my house. Did a compression test- looked great, right where it was before. 125' ish. Took apart the carb and was presented the pic attached. My Boyeson reed, that I just inspected about 500 miles ago, right at about 4000 miles, had shed one of its petals. Amazingly, it didn't snag a ring and take out the Pinasco top- end. But where is that rascal? If it got ingested, is it still a danger? Do I need to crack the cases and dig or it? Any chance it was "digested" and "excreted"? Need to know, new reeds on the shelf. What's the consensus from the community?

Drop the exhaust ad take a look. But I doubt it you will find it in there, but you may get lucky.

Thanks, that did not occur to me!! Fingers crossed. Do I need to find it before I try running her again? 👍

Only if you don't mind taking chances....and have the coin to spend.

It take little time to drop the exhaust and even less time to pull the head. If you do find it in the exhaust, it will most likely be sliced and diced. But again you may get lucky.

Yea, I have a neigbor that rides dirt bikes telling me to run it, "those reeds burn right up". I was like, not sure about that…

I was running about 63 mph when it gave up, so hopefully it was blown right through. I'll let you know what I find in the morning. Thanks!

Pulled off the exhaust, and a lot of flakes that looked like soot/ carbon came out, but nothing like a whole reed petal, or even identifiable pieces. Again, my compression is at about 125. I pulled off the head, dropped the rear shock mount and removed the barrel. There was some light scuffing on the top of the piston, which I'm pretty sure came from the reed, but nothing that you could catch a nail on, and the barrel lining itself looked perfect. I blew some compressed air into the crank case, nothing came out but a little oil/ gas, so I put it all back together. I took the old reed and hit it with a propane torch to see how resistant to heat it was, and it burns (these are the Boyesens) In fact, it crisped up and flaked away. I feel like any damage that this was going to do, would have been done. Am I making an unsound & dangerous assumption? Should I bite the bullet and pull the cases apart to be sure? I know, my bike, my coin. I sure do get the jones when she's off- line.

There are many others on here that could advise you better than me, but my feeling is that it is in the crank area still. It may have gotten into the cylinder, or parts of it, but at this point with the cylinder off, it is not a lot more work to split the case and you can even do it without removing the engine from the frame if you have a tidy place to do it in.

That's the conclusion I came to. I now have them split, and there was nothing there.. I cleaned out the small side bearing and have some peace of mind that junk isn't circulating around the crank, waiting to hit a happy spot and blow everything up. I knew in my heart it was the right way to do things. Thanks for the replies!!