the muffler is done. I installed it this afternoon. I only test rode it on flat ground. tomorrow I am going to get some gas l, and there are a few hills to ride up between here and the gas station, so I will get a good idea what kind of torque this pipe gives me. I will report back again tomorrow.
What do you think of this exhuast?
- Thread starter jtgolden
- Start date
ok I didn't report back for awhile because no one seemed that interested anymore. but I have a report as well as an update. the way I had the pipe put together and installed wasn't working so I took it apart. I know I didnr do it right because I was able to take it apart with my bare hands. I was going to use sheet metal and hose clamps to put it back together, but then I saw a fiberglass kit at walmart for around 12 bucks and I grabbed it. the kit included 8 ounces of resin, a small tube of hardener, a square yard of cloth, a mixing tray, a mixing stick and a spreader. I reassembled the pipe using fiberglass and now its solid. my muffler rests against the top of my rear chainstay, so I attached a muffler strap that is clamped around the muffler and my seat tube. its basically just for extra weight support sine I don't know what kind of vibration and bumps the fiberglass can handle. now to report the performance of the pipe. with my last muffler my top speed on flat ground was 23 and uphill was about 13 or 14. I at first didn't see a difference with the pocketbike pipe, but I chalk it up to not having it assembled properly and not having the engine tuned for the pipe. since figuring out how to tune the engine for this pipe, my top speed on flat ground has increased from 22 to 28 and uphil from 13 or 14 to at least 18 and in some cases as much as 20. the pocket bike pipe has an extremely short header, so I lengthened it by starting with the header from the stock muffler and then adding another two inches or so that was cut from the tailpipe of the pocketbike pipe. I took some sheet metal and rolled it up inside the sections of pipe to fit them together before fiberglassing. I just had the bike out for over an hour today with no problems. as far as tuning the engine, I leaned the throttle needle out the whole way and I'm running a 25:1 mixture. the spark plug is a nice brown color which is basically a cross between mud and rust. before I leaned the needle out it was black and my head was leaking oil. no more oil leaks now. as far as the idle screw, it is currently set to 4 and 1/2 turns out. I run a 68.5cc engine purchased from luckyearlybird on ebay. I also have the upgraded exhaust gasket. my bike runs better than I could ask for considering it pulls my 290 lb butt around at 28mph on a beach cruiser lol.
bbb My episodes of fibre glass outside a muffler never turn out well. Takes a while but heat frys f.glass. Mufflers fall off* *(but not unless there is a Cop next to me) 
Just be aware it's a very short time fix. 
Just be aware it's a very short time fix. I could see a car muffler getting hot enough to fry glass, but I seriously doubt one of these little engines can get anywhere near that hot. anyway, what I actually did was this. I fitted the pipe together, glassed, coated the entire area that was glassed with exhaust repair putty, then glassed again. if the glass gets too much hotter than what it should, the resin burns or melts. I had the bike running for over an hour, so it got about as hot as it ever would, and nothing happened to the glass. I also plan to insulate it with head wrap when I get the money. that stuff ain't exactly cheap and I have no more budget for my bike right now.
On two cycle, what I've seen is that the oil settles in the fibreglass, so you might want to repack after break in.
Repack? The 'glass is on the outside with resin holding it there. Instead of welding it together, he 'glassed it together.
that's exactly right gearnut. I was gonna say that but you beat me to it lol. I don't have access to a welder or even know how to weld. I don't have any buddies that weld, and I can't afford to pay a shop to do it. so glass was my next best choice.
I figured out what to do. if you seal fiberglass, it protects it against heat damage. the recommended solution was bbq paint. it will withstand the temperature of the exhaust as well as seal the glass. my wife is willing to buy the paint for me when she gets paid on Thursday. unfortunately I'm stuck at home till then. I have ridden the bike 3 times since glassing the muffler back together. its still together but I'm seeing air pockets underneath the glass that weren't there to begin with. not sure if that's normal or not, so I'm not riding it again till after I paint it. that will be Friday and I doubt I will ride that day unless I get up early enough. I actually hope I do since I don't do much riding on weekends. anyway, after this weekend, the muffler will be good to go.
I got the paint today. my wife got some extra money. I painted it this evening. gonna reinstall the muffler tomorrow.