pocket bike pipe mod with no welds

timcat · Post by **timcat** » Fri Jan 09, 2009 1:40 pm

yep i found a way to do an exaust mod with no welding of any kind and it works well

Dac · Post by **Dac** » Fri Jan 09, 2009 2:45 pm

that looks cool but you really should do this...

For a few reasons...

1- to long of a downtube before the expansion chamber is a bad thing you loose the good efect of it. So shorting it down some would do good.

2- it wont stick out quiet as far so it will look better

3- Welding it will seal everything off better and it will perform better.

I also see a small flaw with the way the looks right now. You stock the pipe in the downtube and not over the down tube.

Now, Note- The red arrows point to where there is drag. Slowing exhaust flow and giving you less performance.

After, no points for drag and better flow.

nysnowborder · Post by **nysnowborder** » Fri Jan 09, 2009 2:56 pm

lmao good drawings but funny

Dac · Post by **Dac** » Fri Jan 09, 2009 3:06 pm

nysnowborder wrote:lmao good drawings but funny

im on a laptop mouse with Paint,

give me a break man im no artist

keithw · Post by **keithw** » Fri Jan 09, 2009 3:53 pm

Good work! Being a bit long will push the peak of the power curve to a lower rpm and the long head pipe will widen the power band. The real proof is of course in the riding. My thoughts would be to shorten up the head pipe as much as possible and move the expansion chamber farther forward.

keithw

timcat · Post by **timcat** » Fri Jan 09, 2009 6:36 pm

here are the rest of the pics it works well i just tryed it out i think im going back to my stock belt cause it shakes on take off using a .5 in belt. the belt makes it shake i belive due to being to short its too cold for a nother test run i did like 4 or 5 and at only like 5 to 10 min each it was way too cold. now the smaller pipe the silver one works good but is a lil quieter than i was hoping for . the black bigger pipe works verry welli cant say better yet cause im not satisfied with the amount of time i got to do my testing i would have liked each test run to be 30 min. i did have a more powerful mid range but not any different top end but i found the carb needle clip to be in the wrong slot. it has 5 slots i belive . but i have one with 3 either way its in the middle now i will be setting the one with only 3 slots and testing it soon to. idk if the different needels make any difference . but what i can say is the larger pipe the black one sounds like a small dirtbike but i wasent getting to full rpm while riding with either one so its back to the stock belt and as many of you that have helped me may wonder i got my bike running fine otherwise by bypassing the bystarter . i plugged the air intake to it and it solved the problems there . and as far as not having to do any welding on the pocket bike pipes i took several pics to show how i did this here they are i think a coupple hoseclamps are ill it needs now but feel free to let me know what you think

timcat · Post by **timcat** » Fri Jan 09, 2009 6:39 pm

one other thing i do think the chrome pipe will work better if i drill a coupple holes around the silencer

keithw · Post by **keithw** » Fri Jan 09, 2009 7:00 pm

timcat wrote:one other thing i do think the chrome pipe will work better if i drill a coupple holes around the silencer

Other than being louder it will most likely work the same. Repeat after me, "louder is not always better".

keithw

timcat · Post by **timcat** » Fri Jan 09, 2009 7:15 pm

the wider belt i put on this spree dont want to work too well it shakes when i go to take off i had been running pre mix in my tank . but i know my oil pump works now so ill be draining that and going with fresh gas as soon as its gets nice out . i know louder is not always better but this pipe i got brand new in the mail has 2 major flaws the silencer is riveted on and the exaust hole is only bout .5 in diameter i think the wider shorter belt is not working too well im not gettingup to full rpm and it shakes bad at take off so stock belt is going back in . however i did put the gears in this spree from a 87 they are different than the 84 by 1 tooth on the small gear and the exaust hole on the larger pipe is about 3/4 in so i think i need to derestrict the pipe i ordered

timcat · Post by **timcat** » Fri Jan 09, 2009 7:23 pm

ok this here would be impossable to get a pic of but the pipe i got the crome one actually has a washer welded in the silencer to restrict it i just found out my shining a flashlight in it so ill be derestricting it

timcat · Post by **timcat** » Fri Jan 09, 2009 7:46 pm

so i just poped the rivets on the silencer and guess what theres a spacer soldered into it and all this fiber crap packed inside it as well . i had a hunch it was restricted

this pic shows the restriction here on the right side

timcat · Post by **timcat** » Fri Jan 09, 2009 11:15 pm

i send thanks to all of you who have helped me out with my spree its now time to bring the other one on in and work on it it starts on the first kick every time now and sounds bad * with this new pipe . ill get it welded soon. but it sounds really nice . but thanks again to every one that has helped me out on here

Kenny_McCormic · Post by **Kenny_McCormic** » Sat Jan 10, 2009 2:43 pm

Probably needs a rejet, do a plug chop.

timcat · Post by **timcat** » Sat Jan 10, 2009 4:51 pm

ill do that as soon as the snow melts and illl take a pic

Clivester · Post by **Clivester** » Sat Jan 10, 2009 6:12 pm

I notice the pics don't show a mounting bracket to support the main weight of the pipe. I hope you plan to fabricate one

, because without it there's a pretty good chance the resulting vibration will either loosen the exhaust manifold nuts or maybe even shear the studs off.

It'll b interesting to see the results of the "derestricted" silencer.

By the way, where was the black pipe from - was that the one listed on eBay?

Clive.