I find the Tanak PF-4000 ear shattering loud !

GoldenMotor.com

5-7HEAVEN

Well-Known Member
Aug 2, 2008
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The Happy Time expansion pipe from SBP bolted directly onto my GP460 engine. The engine is mounted upside-down, so there was enough room to install the pipe above the engine. The boomerang-shaped expansion chamber is mounted where the top tube meets the seat tube. Then it takes a 90-degree bend with exhaust hose along the chain stay and ends with an SBP lawnmower-type muffler.

This pipe is EXTREMELY quiet. In fact, it is much more quiet than the stock muffler. Its round exhaust flange bolts directly to the 460's square exhaust port. Port matching here might make more power.

More than likely, the HT pipe can be adapted to the Tanaka engines to quiet them down and extract more hp. It would be a simple matter of matching the larger exhaust flange to the expansion pipe.

BTW, this HT pipe adds more hp and does not seem to restrain high rpm.

ANNND, it's cheap.dance1
 

Otero

Member
Feb 1, 2010
782
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wa
meanwhile, way after the fact, I found my stock pf4000 got quieter
after break-in. Was still loud, so I built a sound deadening stealth
cowling that further reduced noise about 30%.
 
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Otero

Member
Feb 1, 2010
782
17
18
wa
So's pedaling. If I could find and afford an electric with the speed and range
of my Tanaka, I might consider it. When I find a quiet, relatively flat back road,
I enjoy lifting off the roller and just pedaling. Having the option, I can make the
best of both modes.
 

lowracer

New Member
Oct 17, 2008
1,319
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Charleston, SC
I'm running a Tanaka 40cc & Tanaka 47r on my motorized bicycles
Both are equipped with poo-poo pipes (stock china girl mufflers) & much quieter than their stock cans.
I also wrapped both with black header tape to avoid the accidental burn.
If anyone wants to sell their Tanaka 40, I'd be interested...
-lowracer-