Ironhead cv carb help plz It's popping!

["K"]

I got the 71 xlh started today. It's poping out of the front pipe. Seems like it's using alot of gas also. pulled the plugs and the front looked clean and back plug was black!!! I'm using a stock 96 flh cv carb, v-tech ignition, and a 5ohm coil single fire, and drag pipes for now. Didn't ride it, still on the table lift. It seemed to be misting out of carb (back pressure) but it had great throttle response. It also seemed that the back cylinder got hotter than the front( odvious from the looks of the plugs) Any input would be great. It's my b-day sat. and I wanted to ride. Been working on it for 2 yrs now. How do I adjust the cv-carb, and what jets should i be running? any other thing i should check? Thanx in advance!

[Mike650]

you might have to lose those drag pipes. or at least baffle them for some back pressure.
Something like this is cheap and easy. this is how i ran my old pipes and it stopped the popping for me.

[IronMick]

May be some useful info in this Sticky ...

Ironhead 40mm CV Carb Swap Today
http://xlforum.net/vbportal/forums/s...d.php?t=636098

[mike131]

did you check your valve adjustments?sounds like you may have front cylinder intake valve not closing all the way

[GA_Ironhead]

...How do I adjust the cv-carb, and what jets should i be running? ...

42/45 and 170 main should be close.

Start with these 2 links and see where it leads you.

http://xlforum.net/vbportal/forums/f...splay.php?f=34
http://www.sportster.org/tech/

Try the lollipops. You're going to have to tune around those drag pipes and the reversion wave that they cause.

[doodah man]

Originally Posted by "K"

It's poping out of the front pipe. any other thing i should check? Thanx in advance!

i'd say check for intake (and exhaust) leaks. if your intake seals are dry rotted, replace them. make sure that carb is supported with a bracket to prevent future intake leaks (if it's not already).

["K"]

Thanx guyz, I figured it out. The coil was only popping on the rear cylinder. It was failing on the front and finally went. Rule of thumb, dont run old shit, assuming it still is good!