New parts! Exhaust, scoop. Pic and questions  By  paulgendek (Read 1,749 times)

Tom, no, it's actually an exhaust for a 50cc GY6 4-stroke. However, it appears to be identical to those used on 2-strokes.

Way back in the sixties, I raced karts (which were ALL 2-strokes) and the "expansion-contraction chamber" exhausts were new. They do WONDERS for a 2-stroke (at the rpm they are tuned for) but we found they also gave a modest improvement on a 4-stroke, but not so picky about rpm.

They are a little better at scavenging the exhaust on a 4-stroke than typical high-perf mufflers (like a "megaphone" exhaust) but very quiet. Sorta the best of both worlds!

At least one 50cc 4-stroke scooter comes with such an exhaust from the factory, and at least one Vento model has it too... Though the Vento exhaust is not stainless, it's chromed steel and it's HEAVY... About the same weight as typical factory can-muffs. I know, because I have one in the work-room. (I'm saving it in case the thin stainless one burns through.)

My Xingyue 150cc runs FABULOUSLY with this 50cc chamber-exhaust, and I can highly recommend it. Surprisingly, it also makes it run a tad rich. Not what you'd expect from a completely straight-through exhaust.

And they look really cool... LOL! Brings a lot of double-takes at the local parking lots.

At idle, and up to mid-throttle, it's quieter than a stock can. At WOT up toward 7K rpm and above, it barks a little, but not objectionable.

Ride safe!

Leo

You're most welcome, bro!

I guess I should add where I got it, since they are not all that common. I found it under the cushions of a used couch at a charity store... I suppose some long-forgotten ex-husband had hidden his purchase there... LOL! They wanted $7 for the couch, so I offered $7 for the pipe and they could keep the couch... Yup!

They do turn up on eBay new, now and then, brand-new and pretty cheap. Often from England of all places. You might find something similar in used 2-stroke go-kart parts too. The 50cc headers won't bolt up to a 150, so I made a header for it. I don't like the small-diameter of the stock 150 headers either, so I used a full 1-inch inside-diameter flex-exhaust, and a cut-up header from a John Deere generator. You CAN buy nice 1-inch headers for around $50 and that's really a better idea...

So far, it's worth the effort. Time will tell, but I think it will hold up at least as well as the cheap mufflers, and it's easy to tune with, and runs well.

Somewhere in the old posts, I have a whole "how-to" on it with pix.

Ride safe!

Leo