admit it... you just wanted a reason to get the SBP expansion kit right away...
Lol, Baron, as Tanaka 40 once mentioned to me, "until your next 'design change'..." lol
My friend Rick installed a Happy Time stock muffler on his 460 engine. It fit and it works. Sooo, if HT muffler fits, then SBP pipe SHOULD fit and work even better!
AND IT DOES!
I installed it and a K&N air filter yesterday. Headpipe installed directly over my upside-down engine and below my 4-liter Happy Time fuel tank. Expansion chamber does a 90-degree at the seat tube, then extends via hose to SBP muffler near the rear axle.
Testrun up the grassy hill was my best ever, and in 2nd gear at that! Must be that extra midrange power.
Yesterday, I threw my bike into my van, dropped the van off at the repair shop, then rode my MB home, five miles away.
No dizziness, no headaches and quieter than the stock muffler.
Much more power, of course, looks good too. Pics to follow, when my friend Hawaii Ed and Rick see my bike.