Hi folks! I'm kind of new to the forums here and I got here because Im having a problem with my 95 FXD superglide. I'm hoping maybe someone here can help me out or point me in the right direction.

Heres the basic question.. can anyone explain or point me to an online reference on how to adjust the air intake on the bike?

Last year before it got put away for the winter I had some work done and got hi flow air cleaner on it. Since then I have had an issue where the bike seems to be misfiring and backfiring. Like at about 3k rpm the bike just goes rrrrrrrrpftrrrrrpftpftrrrrrpftrrrrr.
When its idling these misfires become small backfires. Also when letting off the gas / lowering the RPM the bike backfires constantly
However if I pull the choke on it everything ceases and it runs fine as long as the choke is pulled, which leads me to believe the air intake is running a little high. I would take it back to the shop that did the install etc butI have had nothing but bad experiences with themand I refuse to go to them anymore.

heh heh I am not a mechanic. And I just dont have the money to take it somewhere else and have them charge me over $100 to do a quick adjustment. I love to ride, but this is making me hate to take it out anymore and Im at my wits end.

Can anyone help me out here with what I have to do, where i have to do it etc? or point me to some resource online where i might find this info?
Any help would be greatly appriciated.

Thanks in advance..

-Tarl

 

by allowing more air into your system - via the better flowing filter - you have created a lean condition in the bike. When you pull out the choke, you are adding more fuel to the system and compensating for the lean condition.
You need to adjust your carb, and probably put different jets in it - I'm not real up on carb's, but there are plenty of folks here than can help you out.

you could just put the stock air cleaner back in until you have it all figured out what you want to do - like take it to a shop and tell them you want to do a Stage I upgrade (which is intake, exhaust, and rejetting of carb).. and let them take care of it for you

some of this reply is based on assumptions.... what "work" did you have done already?

 

not carb knowing on the hd's but know plenty of stuff about carbs. to kill the idle backfire adjust your air screw on the side of the carb you will want to turn it in till it seats and then back out 2 full turns and if you still got it then you need a new idle jet. the air screw is not doing anything more after 2 turns, again i dont know where it is but there is one. next step will require removing theair cleanerand carb to replace the mid range and main jets to a larger size and this is done by reading the number on the jet and a bigger numbers a bigger jet and a smaller is well you get it. its pretty simple to do yourself. most likly the main will have to go up and since you say its bad around 3k i believe yer still in the mid range jet so that will also go up. im no expert but this should be what your lookin at, again its pretty simple and the jets only cost a few bucks so if you can get comfortable with it and do it yourself you will save alot of $$. hope this helps get you in the right direction

 

This is only a suggestion......you may benefit from installing the old air cleaner set up without changing anything else and see if the bike runs better. If it does then you have nailed the cause of your problem.
However, if it still runs the same, then you have other problems. Running at 3000 rpms you are definitely on the main jet. Running at idle and a bit above you are using the low speed needle (fuel/air adjustment). You are getting backfires when you back off the throttle and getting 'spits' while on the main jets.......that sounds like you could have an air leak in the manifold/carb connection. Did the mechanic remove the carb and manifold when he did the air cleaner? You probably don't know I guess, but I would look at that before I began changing jets or adjusting the low speed needle.........pg

 

Try this site they have alot of info on the CV carbs, http://www.nightrider.com/biketech/hd_cv_mods.htm, if you still have problems, there are some of us that live near you and maybe someone can help.

 

Wow!
Thank you all for the responses! I never expected so many! =)

Lots of useful info contained in them. I'll be dusting off my tools on saturday and attempting surgery I guess. A few of you suggested I put the old air cleaner back on, but alas the mechanic who installed the new one never gave it to me. He either lost it or kept it for some reason, but its one of the points of contention i have with him. His work was shoddy, he made the bike worse and 'lost' the original parts that he was replacing.
=(

Im sure I'll be posting with stuff like "hey is it bad if the bike is on fire and carb shot through the garage roof?"

thanks all!

 

Lord T.....
Since you brought it up, It is an extremely good practice to never try to start an ironhead without the air cleaner in place. A backfire thru the carb can cost you a good garage indeed........pg