crf50f sounding like a tin can.

[braden.jeffery]

Hey, i recently got a crf50 with a BBR 88cc big bore kit. it was running reasonably well untill i cleaned the carb. I am new to carbs so it was my first time. i cleaned out the jets with an air gun. i put it back together and now its runing like ****. whenever i rev it it sounds like it is overrevving something cronic, and it stays revving for a bit (2-4 seconds) when you take it off the gas( it also sounds like a tin can).whenever i go to ride off it stalls. i have checked the oil, and it has clean fuel. i have searched just about every site to do with a crf50 and still no luck. please help me!

 

[motoXXX]

check:

if fuel line is kinked.

or i bet you have put the carbie pin/needle in upside down or not in properly.

make sure float bowl is set right.

fuel tap is on.

etc etc etc...

 

[bulldog93]

or i bet you have put the carbie pin/needle in upside down or not in properly.

make sure float bowl is set right...

i was just thinking that.

 

[braden.jeffery]

yeah i have checked that. i was thinking maybe the seals between the carb and the big bore kit.

 

[braden.jeffery]

please any other suggestions would really be appreciated. mybe someone has had this problem before and can help mei have tried all oft he above and still no luck

 

[bulldog93]

bolts, are they all tight??? just a thought

 

[braden.jeffery]

yer bro its booked in for a service wednesday. just seeing if ne one could help me sort it out. cheers any ways man

 

[headsmess]

booked in for a service let some doofus apprentice mechanic kill it and pay for the joy

not backing off when you release the throttle? have you got the throttle cable THROUGH the spring? kinked cable? slide around the wrong way? or maybe stuffed(blocked) the idle jet when you re-assembled it...which way through did you blow the compressed air? and, lastly...though im not sure its possible...got the jets mixed up?

tin can? rattling? sounds like maybe pistons got some slap happening(worn), valves have too much clearance, or the exhaust manifolds loose...which would be more popping than rattling...

 

[Flarry]

i was just thinking that.

great! another usefull post from you!

try taking the airfilter off and checking if the carby piston is positioned correctly and not stuck to high, i would suspect you put it together wrong but its hard to know what you did wrong, if the revs dont decrease like they should after you back off the throttle try lowering the idle.

 

[unit_mx]

great! another usefull post from you!

try taking the airfilter off and checking if the carby piston is positioned correctly and not stuck to high, i would suspect you put it together wrong but its hard to know what you did wrong, if the revs dont decrease like they should after you back off the throttle try lowering the idle.

+1 , Bulldog pull your head in. Your posting alot of **** at the moment for your post count.

Take the filter off , sounds like your slide isnt sitting correctly , this can be deceving. Make sure your slide is in correctly ie the wide slot down the side of the slide is sliding into the idle needle which goes through the walls of the carb. You want a 1-2mm gap between bottom of the slide and the floor of the carb inlet. Your slide might be getting caught on the slide. Try inserting the slide then inserting the idle needle. Just play around with it all , set your fuel/air mix at 1 turn out ( Correct position should be around 1-2 turns out ). As you play with you idle make sure to play with your mix , eg you can increase the increase the fuel mix to increase idle. But yeh make sure your gettig that slide in correctly , I know it sounds dumb but its decieving as it may look right. I've done this twice lol , You need to have a small gap. Just play with it for a bit.

An airleak between the carb and manifold wont do this to your bike. I had the same issue , everyone said airleak. It wasnt , there was an airleak but it did very little which was fixed with a new gasket. Just pull down your carb and check everything over , we know the problem is in the carb so we will work only on that!

Check also your float pin is not upside down ( Cone end needs to be down , little switch up to where the floats hit the needle) , having it installed incorrectly will cause the carb to suck in wayyyy tooo much fuel into the bowl and there for it will rev its tits out. Also make sure your needle is seated beneath the wire catch that slots on top of the needle above the clip. Some people make the mistake and stick that little bit of metal beneth the needle causing it to lean out. You can check whether or not if the fuel is comming through the carb correctly by removing the bowl and turning the fuel tap on - fuel should run through the carb. When you push the float up to a level position fuel should shut off.

Keep us informed , piss the service off. We'll fix it!!!

 

[braden.jeffery]

cheers mate im going to pull the carb of and play with it in front of the computer. you guys have been really helpfull with explaining the fine rparts of the carb to a language i understand (basic) lol. i will keep ya informed. I couldnt find help like this on any other site.

 

[braden.jeffery]

you said cone end needs to be down. shouldnt it be going into where the fuel comes through in the carb. ie facing up?

 

[unit_mx]

The little switch at the end of the float needle needs to be touching the floats. When the floats move up they will press in the switch and the really really little pin at the end of the cone comes out and prevents fuel from further flowing into the bowl untill the float level backs off.
The switch needs to touch the floats , the cone must go into that hole.

 

[braden.jeffery]

you mentioned that the cone bit should be facing down. i put it so it is facing up. ie: into the fuel line( or where the fuel enters the carb. i do not see how it can be facing down?

 

[braden.jeffery]

ignore the last msg cheers doing it now

 

[braden.jeffery]

thanks an effing shitload, it sounds like it is fighting fit now. and the revs being held on is from a dodgey throttle cable. i will drop into the honda shop tomorrow and spend 30 bucks ona new cable instead of 250 on a service. thank you so much unit_mx ur an effing legand