muffler

hadog · May 9, 2009

I have been installing kits from ZoomBicycles for a bit now. I am on average happy with them
However their new kits have a black muffler that has a cat. converter in it....it totally robs the power, on some machines to the point that it will not go up an incline.
If I swap put the new muffler and replace it with an older style the kit is great.

Anyone have a fix for these restricting mufflers?

skinnydog1_2007 · May 9, 2009

Get rid of the standard pipe get a tuned pipe. Or take out the baffle. Mine would pop a wheelie on take off with baffle out but heaps noisy

hadog · May 9, 2009

tes but I have 10 lits....don't want to get new mufflers for them all

can't gut the thing because it is all welded because of the catalitic (sp) converter

Norman · May 9, 2009

you can gut the muffler by cutting off the end clean it out then reweld it. Paint it black with high heat paint. Or have it re chromed (expensive).
norman

Cabinfever1977 · May 9, 2009

i have a black cat muff and my bike takes off fast and has plenty of power for hills.
and its real quiet at idle.but i like normans idea.

Forbisher · Jun 28, 2009

Norman said:
you can gut the muffler by cutting off the end clean it out then reweld it. Paint it black with high heat paint. Or have it re chromed (expensive).
norman

I doubt if the guy has a welder so it would not be worth the expense to
pay to have it done

The all welded black "cat"? pipes are junk

The black "cat" pipes from Grubee perform OK and have
a removeable endcap but the black paint burns off right away

The threaded screw holding on the endcap needs to be replaced
with a tack welded stud too

Would be easier and cheaper to buy a new one

The stock exhausts are badly designed for 2 stroke performance

Cabinfever1977 · Jun 28, 2009

i have a black cat muffler from gasbike,the paint on it is still just like new,no peeling or nothing. the muffler is quiet and i though i had good performance until one day the muffler gasket blew out,i had all kinds of power and speed increases,it felt like i was on a motorcycle and it was just as loud as one. i had to replace the gasket because it was too loud for the street. maybe i could make a exhaust cutout valve so when im off road the exhaust would go out a strait pipe and skip the muffler and when im on road i turn a valve to direct exhaust threw muffler, they make these for hotrod cars.

i cant weld but i can drill a hole in the exhaust pipe above the muffler and install a open/close valve to bypast the muffler when i need more power. just a idea i probally wont get around to it.

matt167 · Jun 28, 2009

if you make a cut out on a 2 stroke, you'll cook a hole in the pistion very quick

Cabinfever1977 · Jun 28, 2009

not if you run it to a straight pipe and reg muff.

matt167 · Jun 28, 2009

Cabinfever1977 said:
not if you run it to a straight pipe and reg muff.

if you bypass the muffler with a cutout and a straight pipe, you will create a lean condition and burn a hole in the pistion... it would require rejetting the carb to make it right.. a simple exhaust cutout like you find on hotrods wouldn't work, because 1 way or another it would end up lean

Cabinfever1977 · Jun 28, 2009

i said straight pipe and regualar non restricted muffler. that i would be using 2 mufflers,1 cat black and one with out cat with a valve to switch between the two.

i dont rejett nothing. many people on here use a long straight pipe and small lawnmower muff at the end or none at all.

matt167 · Jun 28, 2009

Cabinfever1977 said:
i said straight pipe and regualar non restricted muffler. that i would be using 2 mufflers,1 cat black and one with out cat with a valve to switch between the two.

i dont rejett nothing. many people on here use a long straight pipe and small lawnmower muff at the end or none at all.

a straight pipe is ok, but it would need rejetted or at least adjusted ( change the clip position ) otherwise the gained flow will cause it to run lean and burn up... even if you had a non cat muffler, and a cat muffler.. the flow charectaristics of the 2 would be diffrent. and at the very least, you would need to tune it to run the non cat pipe as it would flow more, but the mix would end up a little rich when switched to the cat muffler

Cabinfever1977 · Jun 28, 2009

well its still running great,i'll let you know when its not,but it will be a long time from now.

matt167 · Jun 28, 2009

check your plug, I gaurentee you'll find it's burning lean... may take a while, but if you have increased flow thru your exhaust than you have leaned out your engine and it will be detrimental to the pistion... this is why so many kids burn up there dirt bikes.. aftermarket pipes without rejetting.... air cooled engines are very easy to tune, but they need tuning when modding... you can't just expect them to run without being tuned once in a while even un modd'd

Cabinfever1977 · Jun 28, 2009

i havent increase no flow threw my exhaust,i am just using a black cat muff.
and i was saying they are restrictive but are quiet. and that using a regular muffler you would have more power. and that a cutout would have been nice,but was just a idea that someone else had metioned on another post. im too busy to play with the muffler,i have chains and mounts to keep me busy.

and my sparkplug is just fine.

matt167 · Jun 28, 2009

you were talking about the cutout, so I assumed you had that setup, or changed the pipe out with something less restrictive.. if you just have a cat muffler, then that would be a basic stock setup, and as long as it's burning right, it'll last a long time.. but if you ever did, it would need some carb adjustment..

xlite · Jun 29, 2009

Cabinfever1977 said:
one day the muffler gasket blew out,i had all kinds of power and speed increases,it felt like i was on a motorcycle and it was just as loud as one

maybe i could make a exhaust cutout valve so when im off road the exhaust would go out a strait pipe and skip the muffler and when im on road i turn a valve to direct exhaust threw muffler, they make these for hotrod cars.

It happened to me a couple times. Much more power. Once I put on couple hundered miles like that but the noise is unacceptable in the city so I put a new gasket on.

Maybe it's like running with no air filter, more power but not good for the bike. It didn't seems to hurt my engine but who knows if it ran like that for a long time.

Some time ago they had a gimmick for the exhaust that was a washer which muffled when it blocked the pipe but could be turned sideways for power. I'm think of trying it myself.

TheE · Jun 29, 2009

I got my bike from ZoomBicycles too and also got a cat hush muffler. ZB is aware that these mufflers rob power, and they say they're looking into getting better ones. Still, you can modify them easily enough. They have some good how-to's in the forums.

Search

muffler

hadog

New Member

skinnydog1_2007

New Member

hadog

New Member

Norman

LORD VADER Moderator

Cabinfever1977

New Member

Forbisher

New Member

Cabinfever1977

New Member

matt167

New Member

Cabinfever1977

New Member

matt167

New Member

Cabinfever1977

New Member

matt167

New Member

Cabinfever1977

New Member

matt167

New Member

Cabinfever1977

New Member

matt167

New Member

xlite

New Member

TheE

New Member