Sophomore Rider
Currently Offline
Posts: 174
Likes: 1
Joined: Mar 17, 2013 11:51:20 GMT -5
|
Post by indymoped on Apr 6, 2014 16:46:29 GMT -5
I put an exhaust on my 150cc scooter. It ran great before the exhaust change now it will run ok when cold but will bog towards 1/2 throttle. Once it is warmed up it will bog at even 1/4 throttle. I changed the jet from a 120 to a 125 and that didn't make any noticeable difference. To me the spark plug looks like it is running good maybe a little on the lean side. But any bigger than 125 seems a bit too big for my mods. All I have is a free flow air filter, a slightly larger than stock cam and a home made exhaust pipe with an FMF muffler. Usually anyone who needs bigger than a 125 jet is running a big bore or stroker kit aren't they?
The fact that it bogs worse when warmed up also leads me to believe it needs a bigger jet because it is being supplied with less fuel once it warms up and the enricher cuts off the extra fuel. But i'm looking for some second opinions. Thanks for any help in advance.
|
|
|
|
Post by alleyoop on Apr 6, 2014 16:59:40 GMT -5
|
|
|
|
Post by geh3333 on Apr 7, 2014 1:31:53 GMT -5
It's somtimes hard to get a performance type exhaust to work well without certain mods . Has to do with back pressure . It's always smart to match the header , head , intake and carb ports as close as possible.
|
|
|
|
Post by millsc on Apr 7, 2014 23:30:28 GMT -5
A bigger carb will add more top speed if the head is ported paired with a performance manifold, I run a smaller carb which provides better acceleration and take off due to faster air flow. I probably could get a 30mm flat side and get better top end but it does 71 gps now and takes off like a rocket good enough for me. No need to run a performance exhaust without an open air filter. Mine is maxed bored and stroked I use a 120 jet
|
|
|
|
Post by alleyoop on Apr 8, 2014 0:02:56 GMT -5
How big is the homemade exhaust pipe, can you take a picture of it and the muffler. Also what number cam did you put in. To me sounds like your over jetted, try a 115 or 117 main jet.
I have all the goodies, advancing CDI, Iridium plug, hot coil, free flow supertrapp muffler, 1 1/4 pipe I had made, free flow filter added 30cc to the motor and running with a 22.5 main jet and #38 pilot jet. A 125 main jet was to much fuel, was popping on high rpms.
Alleyoop
|
|
|
|
Post by skuttadawg on Apr 8, 2014 0:11:10 GMT -5
I was thinking he may be overjetted too . I tried out some large MJ when I put a BBK on my 2T with Uni and racing pipe but it sputtered instead of bogging . I went down to a smaller MJ and one the third time it ran like a champ . A Uni or K&N type of airfilter ? Did you oil the airfilter ?
how did it run with the stock exhaust ?
|
|
..BAD TO THE BONE..
