Freshman Rider
Currently Offline
Posts: 90
Likes: 0
Joined: Jul 27, 2013 19:40:42 GMT -5
|
Post by sickopsycho on Aug 30, 2013 23:38:28 GMT -5
I am having trouble tuning my carb. I have a taotao 50cc with a 72cc bbk installed. I have a new keihin carb on it with a #  jet in it. I have an #  jet to swap out with the # if i need to. Anyway I have a high flow air filter on it as well. My question is this- I'm familiar with adjusting air/fuel in this carb... you warm up the engine, crank the adjustment screw all the way closed and the engine should die out from running too lean. You crank the screw back open and find the "sweet spot" where the idle is the highest and then a quarter turn towards rich after that. When I crank that screw all the way closed (tightened- all the way to lean) that is where the idle is the highest. ANY adjustment back towards rich and the idle lowers. What gives? I did a plug pull and I seem to be running ok...maybe a tad lean but I don't remember the plug being as white as the picture depicts it.   Heres the problem- I would like to richen the mixture but when I adjust the screw to rich my idle lowers so it seems like I'm not tuning it correctly. I am not very familiar with adjusting the clip on the needle, does this have something to do with my problem? I haven't adjusted it but I know there are like 8 different slots it can move to... What gives? Why is it not dying out when I screw it all the way lean? |
|
|
|
Post by geh3333 on Aug 30, 2013 23:44:09 GMT -5
Seems like your suckin air from somwhere else. Also when you close the air fuel u should be rich. Opening adds more air and then should be the leaner setting.
|
|
Freshman Rider
Currently Offline
Posts: 90
Likes: 0
Joined: Jul 27, 2013 19:40:42 GMT -5
|
Post by sickopsycho on Aug 30, 2013 23:57:47 GMT -5
[replyingto=geh3333]geh3333[/replyingto]Well, I could be entirely wrong, but I think that the screw adjusts the amount of fuel that is delivered, rather than the air delivered. I'm also pretty sure that tightening the air/fuel mixture screw clockwise leans it out while counter-clockwise richens the mixture. If I'm wrong, please let me know as it would be as simple as upjetting but I think I remember experiencing the same problem with the # jet which is one size larger... |
|
|
|
Post by alleyoop on Aug 31, 2013 0:11:14 GMT -5
You are correct Sickopsycho, You have a CV carb not a 2 Stroke Slider carb(which have an AIR RATIO MIXTURE SCREW on the RIGHT SIDE right by the Air Inlet side of the Carb.
Either your PILOT JET is to big or your sucking in extra fuel from someplace else. Check your Vacuum line going to your PETCOCK and see if it is wet which means fuel is flowing through the Vacuum line which means your petcock is bad. The other thing to check is your ENRICHER may not be shutting off the extra fuel after 3-4 mintues and that sucker feeds a lot of fuel.
The needle has nothing to do with the Idle at this point so don't even bother with that. That comes into play as the cylinder rises when you let more air in to lift the Diaphgram that holds the needle. The other only thing I can think of is if your carb has an ACV valve that Diaphgram may be ripped and allowing fuel to also be sucked out.
Alleyoop
|
|
Freshman Rider
Currently Offline
Posts: 90
Likes: 0
Joined: Jul 27, 2013 19:40:42 GMT -5
|
Post by sickopsycho on Aug 31, 2013 0:11:43 GMT -5
Also- what controls the opening of the automatic choke in these bikes? I know the auto-choke gives the bike more gas until it is warmed up, but is there a sensor or what that determines when the choke opens and closes? It is wired which would lead me to believe that it has some sort of input- just trying to narrow down what might be causing this issue- and all of the articles I'm looking at online seem to suggest what I'm thinking- that the screw leans the mixture when turned clockwise- richens to counter clockwise. Suggestions include adjusting the needle to a leaner setting but my plug chop would suggest that I'm already running pretty lean... I'd just like to know why I'm not dying out when i crank that adjuster all the way tight...
|
|
Freshman Rider
Currently Offline
Posts: 90
Likes: 0
Joined: Jul 27, 2013 19:40:42 GMT -5
|
Post by sickopsycho on Aug 31, 2013 0:15:08 GMT -5
[replyingto=alleyoop]alleyoop[/replyingto]not sure what an acv carb is but I know for a fact that the diaphram is good in the top (*edit* I just looked up an acv valve and yes I believe my carb has one- I have not inspected that diaphram but like i said the carb is brand new so it SHOULD not be bad... I thought that was a pump to squirt gas in when you hit the throttle as there is a rod connected to it I believe? Like the accelerator pump of a carb?. I've had it off several times since I've experienced the issue and it's in good shape. It's brand new (like 3 months old) too. I will check the line running from petcock- i read that suggestion a couple minutes ago in another of your posts. Also do you know what controls the enricher? Is there a temp sensor or something? The enricher itself is also brand new with the carb so if it's self contained I would not imagine it to be bad- it's a keihin carb so it's of higher quality... I'll leave the needle alone, though, thanks. How does that plug look to you? I ran it at WOT for about 30-45 seconds and hit the kill switch, slowed to a stop and pulled that (seriously HOT) sucker out and that's what it looked like. Little lean looking, no?
|
|
|
|
Post by geh3333 on Aug 31, 2013 0:17:08 GMT -5
Am i right or wrong about the arifuel. Adding more air to the fuel leans the mixture. And please correct me if im wrong but a clockwise turn tightens and closes off the air. And counter cl opens adds air to the mixture. Please let me now if im wrong . Thanks
|
|
|
|
Post by alleyoop on Aug 31, 2013 0:19:06 GMT -5
The enricher BY DEFAULT the plunger is RETRACTED which in that position allows fuel to be sucked out from the ENRICHER outlet by the butterfly. The Enricher gets fed voltage as soon as the motor is running and keeps feeding voltage till you shut the motor off.
Once the motor starts and the ENRICHER is getting Voltage the gel inside the The Enricher melts and expands and pushs the PLUNGER OUT about 1/4 of an inch from its retracted position to block the air inlet, fuel inlet and fuel outlet to the intake. The Enricher's Plunger usually takes about 3-4 mintues to fully extend out to shut the extra fuel after the motor starts.
But like I mention in the previous post, you either have a to big of a Pilot Jet or your sucking fuel from someplace else.
Alleyoop
|
|
|
|
Post by alleyoop on Aug 31, 2013 0:22:23 GMT -5
Oh, I forgot to answer your other question.
Yes your correct, If you have a CV carb IT HAS A FUEL RATIO MIXTURE screw.
A. Turning it CLOCKWISE LEANS it, meaning it CUTS of the FUEL AMOUNT being sucked out through the Pilot jet.
B. Turning it COUNTER CLOCKWISE RICHENS it, meaning it allows MORE FUEL to be sucked out through the Pilot jet.
Alleyoop
|
|
Freshman Rider
Currently Offline
Posts: 90
Likes: 0
Joined: Jul 27, 2013 19:40:42 GMT -5
|
Post by sickopsycho on Aug 31, 2013 0:25:00 GMT -5
hmm- well this is the stock pilot that came in it- I'll take her apart tomorrow and try to note the size (I assume it's stamped like the main jet). I'll also check the petcock. Thanks for the explaination of the enricher- so it's like a thermostat in a water cooled vehicle? When the gel heats it expands and moves a plunger. Neat... Also geh333 you are right that adding more air makes a leaner condition but the screw controls the FUEL and not the AIR. Screwing the air/fuel adjust screw clockwise reduces the amount of fuel let in, creating a leaner mixture (more air/less fuel= leaner).
|
|
|
|
Post by geh3333 on Aug 31, 2013 0:28:37 GMT -5
I am wrong i was thinking the airfuel just adds and cuts off air, it actually adjusts the fuel also . Couter adds fuel and clock adds air i think i should get some sleep lol.
|
|
|
|
Post by alleyoop on Aug 31, 2013 0:31:50 GMT -5
Here is a carb with a ACV Valve, if yours is a 50cc it may not have one it may have a an Excelerator Pump which if you twist the throttle it pushs the plunger down and squirts some fuel into the venturi. Here are the differnet carbs: THIS ONE HAS AN ACV VALVE you can see the round piece with a Vacuum line going to it.  Here is a Carb with a PUMP NO ACV VALVE:  |
|
|
|
Post by geh3333 on Aug 31, 2013 0:32:43 GMT -5
Thanks i just figured that out. Lol wow i havent worked on my car in aabout 2 yrs so please forgive me lol.
|
|
|
|
Post by geh3333 on Aug 31, 2013 1:08:55 GMT -5
I remember now , the ai fuel at least i was alwas in belief that it only adds or cutts off fuel . The same amount of air is always present . So left turn adds fuel and right turn cutts off fuel. Left dosent cutt off air it adds fuel. Wow that ha me all screwed up. I new that opening the screw added somthing and closing it cutts off something. Lol
|
|
|
|
Post by alleyoop on Aug 31, 2013 12:13:10 GMT -5
Your correct on SLIDER TYPE CARBS that most 2Ts have like this one: Alleyoop It has an AIR RATIO SCREW: To Richen the Mixture you CUT OFF SOME AIR.. Turn it CLOCKWISE To Lean the Mixture you ALLOW MORE AIR.. Turn it COUNTER CLOCKWISE.  |
|
jet in it. I have an #
jet to swap out with the #
..BAD TO THE BONE..