05-21-2009, 11:27 PM
Motorized Bicycle Elite Member
Join Date: Apr 2009
Location: Jacksonville, Florida
Petcock positioning ends sputter!
Today, just by accident, I got my bike running much better-
I've started to experience a common complaint I see on these boards- My bike was fading out again just as it got up to speed and started to hum-
(I was hoping to find a thread here)
I'm just coming off break-in, and the motor sort of always never got up to a constant run-
I figured it was some kind of carburetion, but I've been thinning the mixture (Not accurately I fear), and it was getting worse- The other day ran it without the air filter, and same thing-
but I noticed at speed that gas was coming out the air intake (besides annoying leaking elsewhere, often descibed here)
I should have realized- TOO MUCH gas, not too little.
But it seemed to be the opposite, because it ran fine under load and then faded when up to speed.
Also another clue- The slightest closing of choke lever IMMEDIATELY cut power- too much gas to air
(Lever was loose and closing on its own, but now tightened)
Still I didn't get it- I mixed in more oil- seemed to help a little- but not much
I took out petcock filter- more surge acceleration but same top end fade-
Growing frustrated I wanted to come on here and ask about alternate carbs- I still do, because i think the carb is still the weak link here
Anyone know where better ones are available? Cart carbs? Motorcycle? Lawn mower? Anything!
So anyway, I had the thing running back about as well at first, but nothing great,
and before bringing the bike inside I let it cool down- then I went outside and noticed that I hadn't shut the petcock!
So instead of bringing it in and dripping, I decided to close it and run any gas out of the line-
so I took off and clutched the engine- the thing ran great! It was still just SLIGHTLY open, and then got the right amount of gas!
Too open- same trouble
All closed- engine stopped-
It had never occurred to me to adjust the fuel line by CLOSING DOWN the petcock-
but it seemed to work great- I rode a couple of miles and it motored better than ever-
(www.thehearpe.com- my film script, but my bike photo is on the last page- multi-speed Micargi cruiser