Weak-Sauce Acceleration

GoldenMotor.com

mkingsley

New Member
Mar 31, 2011
3
0
0
turlock
So I've had my first build for a couple of weeks now. Great bike and all was running well until a couple of days ago.

Every time I am riding at around 35 miles an hour and I slow down to about 10, accelerating back up seems to be a problem. I can't just gas it up full throttle like I used to, I have to slowly accelerate to get back up to speed or for a more speedy alternative I have to choke up my bike. But we all know how much of a hassel that can be.

I'm wondering if anyone has had a similar problem in the past and knows any fixes to this problem? My throttle cable seem to be operational so that leads me to believe it could be something in my carburetor? Any feedback is much appreciated.
 

mkingsley

New Member
Mar 31, 2011
3
0
0
turlock
Yeah, before I let my clutch out I've got momentum. But as you just said I think I may have a leak. I didn't mention that now when I'm riding I'm getting about 7 mph lower than my top speed was previously. Another few strange things about my set up is that my bike fails to idle. I've been adjusting the pin to try and find that sweet spot and no luck.

Is it true that if I completely remove the idle pin while the engine is running it should die? If so, mine doesn't die. I thought that once the pin was removed the engine sucks up so much air that it shuts down. Any input on what could be causing that?
 

mkingsley

New Member
Mar 31, 2011
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turlock
Cool beans. Thanks for the prompt responces. I'll be sure to respond to this thread once I've figured out the problem
 

2door

Moderator
Staff member
Sep 15, 2008
16,302
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Littleton, Colorado
Definitely sounds like an air leak to me. Double check where the carburetor attaches to the intake manifold and the manifold to the cylinder. This is the most common area for air leaks. There are others but let's start with the simple stuff first.
Tom
 

bairdco

a guy who makes cool bikes
Aug 18, 2009
6,537
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living the dream in southern california
if your bike ran great for a week, and then started having the same problem as mkingsley's, there's no way the main jet could be too big for the carb, unless you've changed it.

it's not like your bike works great one moment, then thinks, "y'know? i don't like this jet. i'm gonna stop working good.."

look for an airleak, if it's the same problem. you might wanna check the fuel flow, too. make sure it's not clogged up with rust or dirt anywhere.
 
Jul 15, 2009
594
1
0
waukegan IL. U.S.A.
You realy have to check everywere to find leaks. Take the covers off and look for fuel res. I just had a leak from the stator mount hole.
http://db.tt/i8q5OoC <-- pic link
That was a bear to figure out at first, but it's very satisfing to fix stuff yourself.
Did you change fuel mix at all ? Or like bairdco say's run thru whole
fuel system.
 

that guy on a bike

New Member
Mar 30, 2011
31
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newmanstown, p.a.
o.k. I sealed everything i could. took the intake spacer out sealed it back in then sealed all the gaps around the clamp. Then i made a gasket for the cable piece tightened that back on. Port matched the intake and the exaust. Took it for a spin and was doing a little better. Started right up, then after it warmed a little i was running it without the choke. Was'nt getting full trottle but slowly on flat i could gain speed. the after 5 five minutes of doing o.k. it started boging and a noticed gas flowing out the overflow. Runs with the fuel valve off untill it starves itself. flowing gas won't stop with it turned on. As fast as its flowing theres now problem with gas getting in the carb.
 

skiball83

New Member
Nov 18, 2010
136
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41
Chicago
Im thinking you have a CNS carb. Red air box. Get rid of it and buy a NT from thatsdax.com for $11 + sh. When you get it adjust the needle to the second from highest notch and try it out. OR...your muffler might be clogged. Happened to me. Take it off and blow through it. If its hard to blow through then drill it out with a 1/4" bit. Good luck...it sucks now but when you get the hang of the china girl you will love it and she will love you, maybe for a long time. Pun maybe intended. LOL. PS check your gas cap. It might not be venting. When it starts running ruff take off the cap and put it back on. If it runs better for a couple minutes, well there is your problem.
 
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that guy on a bike

New Member
Mar 30, 2011
31
0
0
newmanstown, p.a.
ya its the stupid red air box carb. It said high performance so i looked passed the air box.
I think I might have to listen to you Skiball and get another carb. All i hear are good things about the NT. The cns that came with my kit ran great at first utill i broke the intake clamp. All my smarts (and j b weld ) could not get the thing to run right again. I bought a new one (without finding this fourm first)exspecting the same performance but it has been none stop problems from the start. My wife told me to get the cheaper one but I told her this one was better. She was probly right again. Don't want to spend anymore on it right now, so i'm gonna mess around a little more. I can't let this little carb defeat me yet. I'll take all the advise i can get though.
 

Black_Moons

New Member
Oct 25, 2010
205
2
0
Canada, Bc
Hmm. Well, Not sure about your flooding problem, But try doing a run with the gas cap loose/removed, And see if the WOT/acceleration problem persists. That will tell you if your gas cap needs a vent drilled (most do if they have not been.. AFAIK stock ones are not vented properly and sometimes seal enough to stop flow into the engine after a few mins of running, And the 'seal' can occure a few weeks after puting gas in the tank (Rubber gasket expands/gets wet enough to seal?)

Choke will often get the bike running again during fuel starvation till it gets too bad.