I just picked one up on e-bay for my girlfriends 88 Sporty. I planned on putting my spare CV on it (hadn't got around to it yet). I'm sure not spending $450 for an S&S on a bike she rides once every three months. It does seem to fit the carb nice though. I doubt you would have air leaks with this flange adapter.

 

ya thats the same as mine.
i find they split from the vibrations even with a supprt bracket. i went through three of them on my ironhead.
also seems theres a fair distance in between the two bolts to seal.

i think i do have an air leak. i started the bike no problem, but it was popping and backfiring like crazy. i have a malory electronic dist. and that is still set from earlier.
when it warmed up, the backfiring and popping stopped, but as i was testing for leaks she shut down on me, and wouldnt start again.
what would you say this is a sympton off? for the first say 20 mins it runs like crap, backfiring and popping, then settles down and runs fine. also theres a fair bit of black smoke coming from the pipes until it warms up. then stops?
i love these old bikes, but im getting tired of this.

 

If it were me, I would start with NsCoyote's advice and get a propane torch with a hose attached (not lit of course) crack the torch on slightly, you don't need much. Then run the hose around the intake manifold and see if the idle changes. If it either smooths out or gets rougher you have a leak. If not I would then look for chafed wiring somewhere. Maybe an ignition ground wire rubbed through somewhere. It's worth looking for because there is no cost involved, just a lot of time going over the wiring. make sure you don't have loose terminals on the ignition switch...etc. Gently pull and move the wiring while the bike is running. I've found many wiring problems this way.

From what your describing, it almost sounds like an ignition problem. Bikes and cars can run with a screwed up ignition. But they run better warm. Back in the day, when you had bad ignition wires or carbon traces in the cap a motor would run terrible cold (or damp) but when the cylinders warmed up fuel burns easier so the problem seems to go away slightly.

You could still have carb issues like a sticking float needle of something, but the other stuff I mentioned is easier to do first. Good luck with it.

 

it could very well be a coil problem as well, but yeah do the leak test and trace your wires for issues, if that proves nil, do a coil swap with a known good one. when was the last time you adjusted your valves?

 

i was trying the propane method, then it died and woudnt start again. my leg can only take so much from the last 10years of kicking these pigs.
im going to try again this weekend, (off tomorrow), soi can either prove or rule this out.
i will go over all the wires as well as some are pretty old. i'll rewire what i suspect.
is anyone on here running a Mallory distributer? the wires that come out of it are pretty much resting on the front jug. they look to me like they will melt if/when the jug gets hot,and theres nothing that can be done. its just the way its made. im curious to here from someone thats using one as well.
when the bike was apart recently, one of the things i was doing was refitting my gas tanks properly, (dont ask), so an ignition wire is a possibility. i'll take the dash panel off and see if it makes a difference.
last nite i would've sold it fer 20 bucks i was so pi$$ed.

 

i just did a complete valve job in the winter. new guides, and checked the whole top end for wear issues. i also switched from mechanical pushrods to hydraulic. made a jig off a later year pan and drilled out my oil passages in the case. was scary as $hit but it actually turned out perfect.
by the way coyote, yer honeycomb air cleaner's in the mail.
i'll check the coil as well.

 

sweet thanks alot. generally when somethign stumbles liek that cold and then evens out as it warms up, its either a to rich or to lean condition when cold or theere is a fire issue. if theres an air leak when its cold thermal expansion would seal it up when tis warm and cause it to run fine. if you tried the propane trick and it stalled out while doing it then you have a leak, try replacing the gasket on the manifold and put a bit of die electric grease on the flange before pushign the cv int oit and tighten everything up snug. also if you know someone with a 3 ohm coil*the correct coil for electronic distributer* do a swap out to see if its the coil.

 

Been there, just like that!! Bit the bullet and went with a S&S Super E, and glad I did...

 

all u need in the shop to find air leaks,or electrical shorts is a good old fashioned spray bottle of water...set it on fine jet spray and slowly work it around your suspected problem areas and when you find the leak you will know it...and it washes right off with no residue

 

Lucky Harley guys! Only one carburetor! GoldWings had 4-6 carbs! I have none!!!