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rpm take a few seconds to come down.

gig joe

gig joe

Member
I just picked up a 89 flh , the whole motor was done , split cases, upper half , oil pump , S&S carb., ev 46 cam, heres the thing , when I come to a stop my rpm stays at 1,400 then it comes right down to 1,100 with is were I like to keep it, it only take's around 2 seconds before it start's to come down, thing's I checked, idle air, I took apart the gas throttle cleaned it and put it back together , I also lube the cable's from one end out the other. the bike start's right up and shut's right off, no popping or back firing , I think it may run a little on the rich side but no smoke out the pipes when I blip the throttle. the bike pull good all the way to 5,500 with out a glitch, can this just be the way it run's, it doe's have a cam and 9.5 compression piston's. just wondering , any help would be great. P.S I also checked for in take leak's with propane I found nothing. thank you.
 
You have two throttle cables one opens and one closes. If the throttle cable that closes has too much slack in it the carb will not snap back closed and could possibly cause your delay. I had a similar problem with my 87 fxstc. I hope this helps you.
 
CHZWIZ said:
https://cv-performance.com/harley-cv-carburetor-tuning-issues
Click to expand...
thank brother, but S&S is not cv, it's butterfly, but a lot of this would apply , as long as it doesn't get worse ,have time to look into it, believe it or not all this week it's been under 10 degree's on long island, all last week high 60's even 70 in some places on the island. i'm going for a bike inspection and it's 22 degrees out,tonight 8 inchs of snow so I have a little time, but keep the info coming if you can, thank you.
 
Yes sorry for not catching the S&S carb in OP. If not throttle cable adjustment as mentioned I would take off air cleaner and recreate the slow return to idle condition watching the action of butterfly. Maybe try and lower your idle speed a bit. How many miles on carb?
 
S&S carbs have been known to wear the butterfly shaft bushing. If they get worn, air can pass and cause lean condition at idle. Easy to check, just wiggle the butterfly with your fingers and you can tell if there is slop in the shaft & body.
 
Look at your stanchions where the cables attach to the carb. S&S has 2 different heights of stanchions. The shorter version is early Butterfly style carbs or for S&S cables, the longer for CV cables. on the longer version the tallest(most forward to A/C backing plate) should be about 1 1/8" in length. If yours measures about 7/8" then you have the wrong one and cables won't adjust right. That is providing you are using CV cables.
PS: in checking the stock carb for '89 it was a butterfly type. So you should have the short stanchion.
tourbox
 
I tried every thing, i'm going to live with as it's not to bad , if it get worse i'll look into more. thank you for your reply's.
 
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