Wow...sounds like a harley

Sailn · Post by **Sailn** » Mon Jan 15, 2007 8:24 pm

Its a rather humid cold day in Philly, and my Buddy 50 with a 70cc kit and the stock pipe is really running like a dog. Lots of bogging down between 30 and 40, hesitation, etc. So I got to thinking about the bolt in the stock exhaust ( located right before the expansion ). As I understand it, this is where an O2 sensor would go; use to adjust the carb. Well I assumed that much of the hesitation was due to excessive unburn fuel/air in the pipe, so I removed the bolt. It now sounds like a TY-250 I used to ride in high school, filling garing loud. Aceleration is much better, as is response. What does concern me is that 1) there is a small jet of blue flame which shoots out under deceleration, 2) I am partially bypassing the catalytic converter. So I reinstalled the bolt. What this does tell me is that a pipe will make a huge difference once one is available.

Post by **ericalm** » Tue Jan 16, 2007 2:55 am

Um... 70cc kit?

Keys · Post by **Keys** » Wed Jan 17, 2007 4:34 pm

Be VERY careful with the removal of that bolt. 2-stroke engines require more back pressure from the exhaust than do 4-strokes. If you do not have a sufficient amount, the end result will be a hole burned in your piston.

--Keys

BuddyRaton · Post by **BuddyRaton** » Wed Jan 17, 2007 4:51 pm

I think that this is the only scooter that you could say REALLY sounds like a Harley!!! http://www.vintagemotorssarasota.com/Ca ... ey1960.htm

peabody99 · Post by **peabody99** » Wed Jan 17, 2007 9:16 pm

wow that Harley scoot is sweet...a release would be great!

Motorsport Scooters · Post by **Motorsport Scooters** » Sat Jan 20, 2007 1:18 am

Do not run the scooter with that bolt out. You will ruin your piston and possibly other things in the process. Make sure your carburetor is jetted properly for your performance mods.

Sailn · Post by **Sailn** » Mon Jan 22, 2007 6:35 pm

I was concerned about that. When the 70 cc kit went on, the carb was jetted up and it runs rich with the expectation of a new pipe. To date I haven't found a pipe.

As to the bolt droping the back pressure to much, while it does, I am unsure as to the extent. Although I don't have numbers, and it would be difficult to measure what is going on without affecting the situation by taking measurements; there is a significant ( more than half) amount of exhaust still comming out the stinger. I picked up a bunch of 8 mm bolts yesterday, and might try drilling various size holes in them.

Perhaps the best thing to do would be to get a hot Vino pipe ( same top end I think ) and weld on some new brackets.

Anyone have any sugestions as to which pipe?