Pocket Bike Expansion Chamber on 60CC engine

GoldenMotor.com

Mike Hunt

New Member
Jun 9, 2009
184
0
0
Toronto, Ontario
im running a gutted pipe with a top speed of 60km/h. will a tuned pipe give me more performance than what i have now. 60 is plenty top speed for me and i would like more low/mid end power. can it be done?
 

foureasy

New Member
Jul 9, 2009
478
0
0
tucson
i can build you a pipe that will do anything you want. 120 for mild steel, 200 for stainless. 10 to ship to canada, free to the lower 48. i cant seem to find the pic for the stock motor pipe, but here are some others that work extremely well. both have very smooth power. 520-300-1700 clay

highly modified motor w/ stainless pipe.



lightly ported, mild steel.
 

xlite

New Member
Jun 18, 2009
735
0
0
ny,ny
im running a gutted pipe with a top speed of 60km/h. will a tuned pipe give me more performance than what i have now. 60 is plenty top speed for me and i would like more low/mid end power. can it be done?
The SBP exhaust kit will add 3-4mph or you can tune it for more mid/low and only runs about $60.
 

Alson

New Member
May 16, 2010
71
0
0
Kankakee Illinois
Im going with the SBP expansion chamber, they said the header pipe comes ,ong, has to be shortened, I heard 12 inches from engin to tbe begenning of the expansion chamber right aere it starts to get fat will give you good topend
 

BrockB

New Member
May 19, 2011
23
0
0
United States
i can build you a pipe that will do anything you want. 120 for mild steel, 200 for stainless. 10 to ship to canada, free to the lower 48. i cant seem to find the pic for the stock motor pipe, but here are some others that work extremely well. both have very smooth power. 520-300-1700 clay

highly modified motor w/ stainless pipe.



lightly ported, mild steel.
are you using 1" for the header tube?
 

SD moto man

New Member
Aug 27, 2011
101
0
0
San Diego
I just installed the SBP pipe on my bike over a week ago and I am still trying to tune it right. They provide you with 3 hose clamps and 3 pieces of silicone tubing to "seal" the joints in the header and the x chamber. The silicone tubing is completely useless on the header and the hose clamps are very cheap and hard to tighten them over the tubing without stripping the heads on them. The silicone tubing on the header started to melt within the first mile of me testing my bike, and do not seal the joints at all. Even with the tubing and clamps on the header, I can move it with my hand.

As far as the performance, I lost low end and gained a few mph's on the top. I had a stock pipe before without the muffler cap on and I had a lot of low end and it breathed great. With the new pipe on, I can't make it up a hill that I usually ride up anymore because there is no low end. Ive read a lot about tuning the pipe by adjusting the header longer for more torque. Here is the problem with that: since my header is so loose because the clamps and tubing don't seal anything, how can I adjust the length of it when it moves around so much. I don't have access to welding equipment and I read that gasket sealer, header tape, and JB weld doesn't work. It's pretty frustrating getting it tuned because I can't get anything to seal on the header so I'm not sure how much that is affecting the performance. Anyone thinking about buying the SBP pipe should consider that they will eventually need to have it welded, the stuff it comes with is only a very temporary fix to keeping it together.
 

Emerica

New Member
Feb 1, 2008
65
0
0
I feel your pain.
I used a bunch of copper tubing and exhaust wrap for awhile, would work great for a month or so then go bad.
My best suggestion is if you cant get something welded up.
Get yourself a torch, id probably try mapp, or even propane if you go aluminium.
You can find brazing rods in aluminium and i think brass? Youll need something that can burn hotter for the latter. Get some tubing and make a pipe, and the braze up the connections.

I'm not sure what the operating temps on the exhaust is. The bernzomatic alum rods that I have melt about 700 to 750F , I just wouldn't want it getting sucked into the cyl if the temps got too high.
Tomos kitted cyls can get into the 400's dunno about the header though.


I dont run a china or the morini anymore so I gave up on my SBP header.
Id try these alum rods in a heartbeat if I did though, they are awesome for brazing popcans together with a micro torch.

http://www.youtube.com/watch?v=jijW310xvp4 essentially..

I worry a bit about the heat from the exhaust and a higher temp rod might be better, but you may need to melt it with a different gas like mapp, or oxy torch
 

maniac57

Old, Fat, and still faster than you
Oct 8, 2011
4,484
22
0
memphis Tn
i would like to know how they work? i have an old pocketbike sitting doing nothing i think it is a 35cc but ime not sure, anyone out there try this?
It works. well worth the trouble IMHO. (just guessing but I'd guestimate a 7-10mph difference with NO other mods(no jetting)
 

Lazy Dog

Member
Oct 13, 2011
47
0
6
STL
I replaced my SBP and never looked back, my son got too big to race the pocket bike and moved to 125 dirt bikes, so I tried his pipe. It was a pain to mount, had to cut it up and reposition all the angles It is by far the best pipe Iv'e had on any of my bikes and it's so much faster, and sounds amazing. video is with my old CNS, man I miss that carb.
I absolutely love the power band, Since it's so long and starts at the jug there really isn't a power band the engine just seems bigger through the entire RPM range.
 

Attachments

Last edited: