carburetor top end adjustment

[421SmQQthie]

hi does anyone know how to get the factory carbs to be able to run at full speed with out cutting off like a govner until the motor slows back down can you drill out the main jet a little bit or what can i do for this problem anyone know???


i know it is working the way they made it this is the 2nd one ive owned i have removed the baffle and it increased the power alot but still at top end if spits and spudders like has govener

 

[Ghost0]

This is typically due to it running too rich. Try first lowering the needle in the carb by raising the clip position. If that makes it worse then it is probably a fuel starvation problem and then check that you have good fuel flow and your float is working correctly. Checking your plug with be your best indicator of how it is running.

 

[421SmQQthie]

hmmmmm ok i have messed with that before on my other bike and nothing changed is there a known problem with the supply not being big enough? meaning at the carb fiting?

 

[Ghost0]

If you are using the stock petcock and filter they can get clogged. This can also clog your needle and seat in the float bowl.

 

[421SmQQthie]

ok i am wating on a masterlink for my chain i put it on backwords and itfell off but it is brand new everything is new i dought it is clogged and i have had the float apart allready to check the float and all is good

 

[Bikeguy Joe]

Check for a loose jet.

 

[421SmQQthie]

well at the moment i am looking at buying a better carb ive had these same problems with my last bike the motors run badly with the baffel in and when you take them out it dont get enough gas i think not sure mabee a better carb will fix it i had these troubles with last bike too

 

[Gareth]

A better carb will need to be jetted properly as well...


Just pointing that out..

=-)

 

[421SmQQthie]

this is the one i was looking at it is settup for the motor already bicycle Motorized BIKE ENGINE - Performance Carburetor - eBay (item 170433778050 end time Feb-16-10 11:28:30 PST)

 

[michaelgrav]

Spooky Tooth who has a link on the main page sells an upgraded carb for $25 or you can buy the CNS Carb with filter, Choke and throttle cable for $50. It is basically the same one as the ebay link posted but Spooky Tooth I know & trust. I just purchased the CNS and its like nite and day compared to the stock carb! Good piece.
CNS Carburetor for Motorized Bicycles
Check it out!

 

[421SmQQthie]

ok do you think the 25 one is worth a damb or just spend the 50???

 

[421SmQQthie]

well i just ordered the cns one thanks for the info bro i relay appreaciate it that was what i was thinking also them old style carbs are no good for top end ill let you know in a few days when i recieve it.

 

[michaelgrav]

depends on the wallet condition LOL but the $50 CNS is worth the money. the manifold is a lil chincy but it works! Add some locktight or other adhesive on the manifold because at high speeds the carb will blow off! COOL!

 

[421SmQQthie]

do you have any pictures of your bike on the net some were or videos?

 

[michaelgrav]

I'll post a pick of my bike but without Carb upgrade, will post it soon

 

[michaelgrav]

3 speed internal hub jackshaft assembly along with the HP angle plug head, SWS Tuned expansion chamber. Now with CNS carb.. I am hooked can't stop upgrading!!! LOL Like to go Fast and go past those bike riders in their gay gear peddling that ass off!

 

[421SmQQthie]

wow you have a nice set up for sure thanks i will post you when i get new carb installed and let you know how i like it.

 

[421SmQQthie]

thatis sweet i am looking foward to getting the jackshaft settup also i cant afford it now but asap ill get it so ill have 5 speeds and a chamber exaust from sick bike parts asap

 

[Scout Black]

It is very important that the carb is all of the way seated on the manifold. This will fix a lot of carb complaints. An O ring is recomended to act as a gasket.

 

[itchybird]

When I first got my bike on the road, it ran great, it would run at 30 MPH if I pushed it.

Over time, i noticed a slow decline in power, until it got to point where it would barely hit 25 MPH at which point it hit a wall almost as if I had hit a govenor, just like the orig post observed on his bike. I opted for a CNS carb which seemed to help, but I still hit a hard limit. Then it started to worsen.

I removed the petcock from the tank and found the screen was full of crap. I cleaned it out, cleaned out the petcock and problem solved, what a difference. With the dirty filter the flow was reduced to where the bike would starve from lack of fuel. I'd start there...

I've since added a few performance mods: Including a expansion pipe which i modified to port match flange/pipe, a .038 deck of the head, and of course the CNS carb.

Bike now has much more power than stock and just runs great, the only problem i've had is the carb has a tendancy to blow off the back of the intake at sustained high speed runs. My brother has had the exact same problem with his CNS as well. We're now building high flow intakes that will have a tab to hold the carb on tight without overtightening -which by the way is a good way to break the metal casting.

Rich