strait pipe exhaust

[EXTREEK]

i don't really mind how loud it is. i take my 70 in loud places where it doesn't really matter. how much would it effect the performance for the worse or the better? has anyone done it?

[musclebikerider]

extreek is actually me i found my password

[Miniac]

Unless you have the biggest cam you can fit in the head, and an oversized carb, and run with the throttle pegged all the time you won't ever truly see the benefits of a straight pipe. I stuck a straight pipe on a Honda SL100 (back when dinosaurs roamed the earth) and that sucker screamed when I was running WFO, but on the hills with the switchbacks that required some low RPM tractability I actually ended up making things tougher on myself. And the darned thing stalled easier, too. I ended up with an old steel can SuperTrapp welded on it and did a bunch of tinkering with the jetting to get the low end back, and to be honest I don't think it hurt the top end at all. Anything I may have lost on top was more than worth it for the improved midrange.

The other thing I noticed was that loud was cool for the first couple of rides, but once the novelty wore off it was just irritating. And even though I lived out in the boonies the handful of other folks that lived out there were about ready to lynch me when I finally quieted things down.

My recommendation would be a good performance pipe with a decent muffler on it, and spot on jetting. But that's just me.

-kevin

[racerx]

Kevin gave you good advice, there's little to be gained with a stock 72cc motor (that might be a bit tired and down on power because of it) other than more noise. He's absolutely spot-on that a loud, rasping, exhaust will grate on one's nerves in a big way, over time. At lot of guys unknowingly end up shooting themselves in the foot by gutting a stock muffler. More often than not, the power increase is far less than the noise and less than could have been gained had the exhaust been correctly tuned for the application. Your stock motor probably won't make anywhere near as much noise as a larger, tuned, motor. But, that's only because it's not making that much power in the first place. Be aware that carb jetting requirements can differ with different exhausts, so that variable has to be eliminated. And, a quieter exhaust can make a bike seem slower, so it pays to actually measure top speed.

If your current top speed is less than 40mph on the flat, then your engine is probably tired and would possibly benefit from new rings, a valve job, points & carb rebuild. If you're seeing low 40s, then that's about as good as it gets for a stock K0.

[SS_canuck]

These small displacement, conservatively tuned engines sound quite comical idling with an open exhaust. They make a "squeaky popping" sound. Without motor modifications (ie. cam, increased intake flow or increase in compression ratio) to back up the image that you'd be trying to portray by sticking a straight pipe on, is a little goofy. Its a case where less is truly more. Removing the stock spark arrester is a simple way to gain increased volume levels while helping reduce Back pressure.

Compare straight piping a stock CT to a stock Civic with a grossly over sized exhaust and megaphone tip (or just to be fair a tired old 305 with Cherry bomb glass-packs). Neither sound cool!

[musclebikerider]

mine is actually a lifan 110, does that change things at all for your answer?