You may be able to richen it with the needle clip adjustment.

Go to this page and look at the at the pics marked 1,2,3,4 and just below them a pic of some needle nose pliers holding the needle clip adjustment with an explanation of how to adjust it by moving it lower to richen, higher to lean out.

http://www.ministothemax.com/hop_ups_carb_tuning.htm

 

would a older carb work if i bought one new from the dealer? i just dont get what the dude is trying to say. i would rather pay extra and get a new carb so i can just turn a screw.

 

Yes an older carb will work. I was going to suggest it but thought you may not like that suggestion.

I would look for a 2003-2006 stock carb and you should be ok.

Ebay has lots of options fairly cheap.....

http://shop.ebay.com/?_from=R40&_trk...All-Categories

 

whats the best size to get on ebay? what the stock size? If i can go with a 26mm **** i would buy it right now if i gave me more power... let me know. Thanks brotha

 

i would do all the free hop ups shown at the minis to the max site listed in the post above. you will need to drill the main jet at least a size or two bigger to give it more fuel when you give the bike more air like you did by removing the filter or just modding it. you can drill it out with a pin vise & mini drill bits from a hobby shop or hardware store. the stock 13mm carb does not have a removable pilot so ur limited in adjusting that but you can adjust the needle clip position to the lowest spot (raising the needle) to also richen it up from 1/4 to 3/4 throttle. the main jet operates from 3/4 to WOT. if u are buying another carb then just get the 18 or 20mm one, 26 is way too big .. the sheng way is the cheapest china clone and the keihin is the real deal & more expensive.

http://www.ministothemax.com/hop_ups.htm

 

so stock is 13mm? and if i got the 18 or 20mm would that fix my problem so i dont have to adjust the needle or anything like that?

 

Not likely. You will drown the stock displacement. Bump up to 18 or 20 only if you have an 88 kit or larger.

Your carb is the trouble if you checked all gaskets and know everything is air tight. Fix it or get a new one. Same size unless you increase displacement. Too much fuel for a small engine will be flooded all the time and never be right. The lil buggers will only do so much stock no matter how much air/fuel they're getting. Excessive of either does not promote performance. Kind of like putting a cold air intake on a yugo. Unless other engine mods are made, your just shooting yourself in the foot.

There are a couple of stock ones on that ebay search I gave you. Like $79 but might be worth it. Before you rush out and buy one please check everything I mentioned in my first thread. Might save ya the trouble and $. If you have any oil seeping out from head, it can also mean air seeping into valvetrain and is affecting your tune.

 

exactly what he said ^^^ if you are going to spend money and not fix/modify ur current stock carb then just get a 88 kit & a 20mm carb kit.. about $200 total for both. I wouldnt waste $80 on another 13mm carb! If you get the ebay carb kit from Mulisha below shoot him a email and also get the pilot & main jet kit for $10 each so u can dial it in better. you can still have a decent runnin stock 50 if you get a k&N filter, drill out the main jet, remove the choke & plug the hole and port the intake like my opld 13mm carb in the pic below.

88 kit

http://www.dratv.com/600026.html

20mm carb kit with manifold, filter & cable

http://cgi.ebay.com/ebaymotors/CRF50...Q5fAccessories

 

ok heres the update.

I replaced the carb with a friends carb which is pretty new and it did the same thing. Ran ok for about 5 minutes then bogging again and it dies.
That pretty much eliminates the carb being the problem right?

What else can i do?

 

Throw it in the Dumpsta

 

it doesnt matter if the carb is new or old big or small.. if its not jetted & dialed in to your bike then it will bog.. bogging can be a sign of too rich or cutting out can be too lean..if the carb is clean and all jets are clear then i would check fuel flow and make sure nothing is clogged in the line & then do a plug chop..another problem could be your rings, are you getting good compression? also check your valve clearances. it really sounds like it is a jetting issue but it could be other things too so u need to go through the process of elimination.

 

and if all else fails just give it a good YUT UGHHH & a quick BRAAAAAP and that will clear the shitz out of it!!

 

i'm about to

whats up with you?

 

as you can probably tell already i'm a newbie to this 50cc thing. Get me on something with 600cc's and shiet well everyone here knows already

What is a plug chop? everything else looks in place. Tomorrow i will be taking off the tank and checking the hoses and such. If thats not the problem and no other advise this thing is going in the river. Thats my word!

 

also your pretty much saying that it doest matter if i changed the carb because my bike is already tuned that way? SO if i get a new carb which i already ordered one i will still have to tune it?

 

Dude just follow my instructions in my first comment. With the new carb you'll have the external air/fuel mix screw. It's really not rocket science to dial in.

By the way, did you ever pull your fuel hose from the carb and open petcock and see if fuel flows freely? Even a clogged gas cap breather vent hose can restrict fuel flow, as well as dirty petcock screens and cause problems.

The more I pondered your problem, it occured to me that I've also seen a bad ignition coil (lil' box that spark plug wire goes to) make a bike do what you described after getting warm then hot. You might want to see if your friend will let you borrow his for a test.

 

You have a stock fiddy . Use a stock fiddy carb . Probably buy one for like 15 bucks at PM .

Valve adjustment is something you might want make sure is correct to . At least you got it started with your friends carb .

I doubt its an ignition problem cause he said that if he rides with the choke half way closed the bike stays running .

 

i hear ya, ive come pretty close to smashing my pocketbikes with a sledghammer on many occasions..

u need to look at it as a big bike.. if it has carburetors when it comes from the factory it is dialed in for the parts on it ie, stock exhaust, restrictive air filter, any epa ****, pair valves etc.. now if ya go and rip off the stock exhaust and put a full system & a k&N filter and add some ram air ducts on you're gonna need to rejet the carbs with a jet kit and dial it in or it gonna run like ****, mostly dangerously lean from all the extra air being introduced.

On a FI bike if ya made the same mods you need to remap the ecu with a Power Commander or similiar..

same deal on fiddy, you add a new pipe, remove the air box, add a 88 kit, etc, you're gonna need to make changes/adjustments to the stock jetting and/or get a bigger carb and dial it in.

when you took off the restrictive stock air box you basically added more air flow and will need to add more fuel to compensate, thus raising the needle and adding a bigger main jet.. now since it also started running like crap before you made changes which is what i think ya said in the 1st post then i would think sumtin else may be causing the problem like a dirty fuel line or clogged carb/jet, or fouled plug, valves, etc.. .. you really just need top go step by step with checking some of things listed in different replies..could also be spark issue, maybe the boot is bad.. etc.. .but for the most part a bog is usually carb / jetting related

 

I thought about that but usually, valve adjustments needed should yield a bad running motor always. His runs for a while then steadily goes downhill as if something is getting hot or changing as it warms. I have seen a coil do this on an old trail 70.

Just a shot in the dark really, but I know if I had his bike it would be running good by now. Just gotta rule out everything by process of elimination.

 

here ya go, carb tuning 101:

http://justkdx.dirtrider.net/printcarbtuning.html