Sportster CV Carb

[lovechild]

Hello all!

Currently riding a 1989 sportster. Stock pipes, moon air cleaner. Bike was running a bit shit, and it had one of those dynojet kits fitted, so i decided to change back to stock. Stock needle, stock spring,stock emulsion tube, 45 slow and 165 main, and changed the plastic fuel inlet for a brass one. Now the bike will barely run.

I have noticed that when i have the bike is running at idle, if i have the air cleaner off, i can see fuel spraying out from the needle jet. Which then just sits behind the butterfly until the throttle is opened, then the bike dies or has a major backfire through the carb. Im guessing this isnt right!

I have made sure the needle jet is in the right way, with the chamfered edge going into the venturi. Although i have noticed that the emulsion tube doesn't screw all the way in, as there are still threads exposed. Is this right?

Has anyone got any idea whats wrong!?

Any help will be much appreciated, as it sucks finally having some nice weather here in the U.K, and no bike to ride!

Cheers

[GermanG]

Sounds like float level is far to high. Could it be that you have bent the float a little when you changed the jets? I do not have the manual on hand now, but I guess the correct setting is somewhere in the net.
If you can not get it right, sent the good weather south east to Germany for the weekend! Thanks in advance! Georg

[lovechild]

Thanks George, but i already checked the float height and it was right.

[armand]

sportster cv

Ripped the diaphragm?
The xlforum is a great spot for sporty stuff

[blackjx]

The mainjet holder got changed with the kit. It sounds like maybe you didn't change it back to stock, maybe?

[Guest]

http://www.bing.com/images/search?q=cv+carb+diagram&qpvt=cv+carb+diagram&FORM=IGRE#view=detail&id=E072DD641049BFDA94216DF407D0BBE9D45AB52B&selectedIndex=17

Part # 5....is it installed correctly ? If it's upside down, I'm thinking the emulsion tube wont thread all the way in. Try flipping it and see what happens.

http://www.bing.com/images/search?q=cv+carb+diagram&qpvt=cv+carb+diagram&FORM=IGRE#view=detail&id=56BCD2B13D20C43FD0E96226EB63FD71603529A0&selectedIndex=0

On the bottom link, I think it's part #90.....

[lovechild]

Thanks for the replies guys. I have the stock jet holder installed, and the needle jet that sits under it is definitely the right way up. Looks like the slide may have been drilled out so i am going to replace it. However, i can't see why this would make fuel leak up through the needle jet. The only way to stop it is to completely close the butterfly but then the bike dies.

[hillakilla]

are you sure you have the right amount of spacers under the needle, or the clip on the right slot?

[dakota]

diapragm

check the diaphragm if you haven't . It's easy to check, and fix if it is the culprit.

[blackjx]

WAIT! I think '88 or ;89 CV's have no accelerator pump. If you got a needle for the no-pump carb, it'll spray like you describe.

[lovechild]

My carb has no accel pump. So are you saying that fuel spraying out of the needle jet at idle is normal?

Bike wont even start on the choke now. Tried earlier today, and it just backfired, blowing the carb right off the manifold!

Does this sound deeper than a carb problem?

[Guest]

You more than likely have something wrong with the needle seat, needle or emulsion tube. Are you 100% sure the seat is installed with the longer portion up ? Didn't you say the emulsion tube wont thread all the way in ? If that's the case then I'd say you need to double check that.

[Guest]

My carb has no accel pump. So are you saying that fuel spraying out of the needle jet at idle is normal?

Bike wont even start on the choke now. Tried earlier today, and it just backfired, blowing the carb right off the manifold!

Does this sound deeper than a carb problem?

What the hell ? Blowing the carb off the manifold. Crap I hate to go on another carb support bracket rant !!

[nastycitydago]

What the hell ? Blowing the carb off the manifold. Crap I hate to go on another carb support bracket rant !!

Lol did that when the first time I ever cleaned a carb ... Once it flew off , scaring the crap outta me, believe me , ill always make sure I put the support bracket on before running and tuning it, hahaha looking back , shits funny now.