Carb question
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Cruiser
Joined: Apr 2012
Posts: 178
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From: Where our Gov. makes our license plates
Carb question
So I just finished going through my 79 FLH bagger. Mostly cosmetic stuff and some very minor mechanical. She is basically stock except for a super E carb and I removed the stock baffles. Seems to run pretty good except it feels like I lost a lot of low and mid range power. Pulls pretty good at high RPM but not so much at the low... Anyways I noticed that when I let off the throttle say at a red light or something the engine takes a long time to come back to idol. Or if I crack the throttle with the bike in neutral it does the same. Its like its responsive on the way up and slow to come back down.
I just got this bike last fall so its still new to me and this is my first shovel. And suggestions on what could be causing this?
I just got this bike last fall so its still new to me and this is my first shovel. And suggestions on what could be causing this?
Last edited by rapp76; Jul 13, 2012 at 11:06 AM.
Road Master
Joined: Apr 2012
Posts: 979
Likes: 38
From: new orleans,la
what jets do you have inthe carb? 1979 should be an 80" an E where you are IF your at sea level open pipes should be a 70 main jet and a 32 idle tube.. open drags make you lose bottom end .. check the jetting first -- the A/F screw affects the idle andjust off idle -- cold it shoud be like 1 3/4 turns hot 1 1/2 -- i run open pipes but i found a add on by accdent. its the finisher cone off of a 2001 honda prelude-- it gives just enough back pressure to keep that botom end but not affect the open pipe -- see pic
Thread Starter
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Cruiser
Joined: Apr 2012
Posts: 178
Likes: 0
From: Where our Gov. makes our license plates
what jets do you have inthe carb? 1979 should be an 80" an E where you are IF your at sea level open pipes should be a 70 main jet and a 32 idle tube.. open drags make you lose bottom end .. check the jetting first -- the A/F screw affects the idle andjust off idle -- cold it shoud be like 1 3/4 turns hot 1 1/2 -- i run open pipes but i found a add on by accdent. its the finisher cone off of a 2001 honda prelude-- it gives just enough back pressure to keep that botom end but not affect the open pipe -- see pic
I haven't opened up the carb to see the jet sizes yet. Its a 74" not the 80". I set the carb according to S&S procedure but I cant remember right now where the A/F screw is set at. But would a carb adjustment make the RPM slow to return to idol? It almost seems like something is hanging up in the carb or something, just guessing... I don't think your tips will work for me since I have the stock pipes, the last 24" or so is probably 3" pipe.
Has anyone ever tried the bolt in your tail pipe trick when putting on straight pipes???
Tourer
Joined: Jun 2010
Posts: 252
Likes: 4
From: POZO, CAL.
First off, did it run like this with the baffles in? A 24" long pipe with a 3" diameter open hole, doesn't work very well.. I run 1 3\4 drags with baffles,along with a S&S Super E on my 76 FLH... A little back pressure goes a long way......
Road Master
Joined: Apr 2012
Posts: 979
Likes: 38
From: new orleans,la
thats why i run those cones --- a little back pressure goes a LONG way
ok its a 74" mufflers 66 main jet no baffles 68 and a 31 idle -- was it doing the back to idle slow b4?
-- http://www.sscycle.com/carbquickguide/ -- cables can be gummy - check that idle tube since you removed the baffles the idle and low speed is now lean.. -- mine did this and i adjusted the acc screw on the right -- it was getting to much fuel... i have seen people put a 72 main jet in a stock 74 and then try to lean it out with the idle tube.. --- take the cables off the carb and run it without them let it warm up and rev the engine by hand (sitting still) i would still make any jet corrections first .. cold the A/F screw should be 1 3/4 turns --
ok its a 74" mufflers 66 main jet no baffles 68 and a 31 idle -- was it doing the back to idle slow b4?
-- http://www.sscycle.com/carbquickguide/ -- cables can be gummy - check that idle tube since you removed the baffles the idle and low speed is now lean.. -- mine did this and i adjusted the acc screw on the right -- it was getting to much fuel... i have seen people put a 72 main jet in a stock 74 and then try to lean it out with the idle tube.. --- take the cables off the carb and run it without them let it warm up and rev the engine by hand (sitting still) i would still make any jet corrections first .. cold the A/F screw should be 1 3/4 turns --
Road Master
Joined: Apr 2012
Posts: 979
Likes: 38
From: new orleans,la
its not a bolt its a washer welded to a bolt --- look close inside this sporty pipe -- thing is the cones work WAY better .. just sayn
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Road Master
Joined: Apr 2012
Posts: 979
Likes: 38
From: new orleans,la
intake leaks can be tested various ways.
best non invasive is with a spray bottle filled with water and mild dish soap.just a drop of soap.
bike been sittin?
intake bands probably rotted, or installed like ****, thats common.
easy fix.
make sure your points aint stickin advanced, take off the cover, manually move the center piece(cam) watch it move back on its own.
if it dont, theres possibly a spring issue or worse.
easy to fix.
baffles removed...
may have caused your low end flat, but im not inclined to think so.
turn off the accelerator pump and set your idle mix.
then set the acc. pump.
the 2 can play havoc with each other.
once the thing idles, you aint gonna be long to find the acc. pump sweet spot, go 1/8 of a turn out and hit the throttle.
when it stops falling on its face its time to ride.
the faster the bike returns to idle if all systems are normal the richer it is, as you lean it out, it will return slower.
best non invasive is with a spray bottle filled with water and mild dish soap.just a drop of soap.
bike been sittin?
intake bands probably rotted, or installed like ****, thats common.
easy fix.
make sure your points aint stickin advanced, take off the cover, manually move the center piece(cam) watch it move back on its own.
if it dont, theres possibly a spring issue or worse.
easy to fix.
baffles removed...
may have caused your low end flat, but im not inclined to think so.
turn off the accelerator pump and set your idle mix.
then set the acc. pump.
the 2 can play havoc with each other.
once the thing idles, you aint gonna be long to find the acc. pump sweet spot, go 1/8 of a turn out and hit the throttle.
when it stops falling on its face its time to ride.
the faster the bike returns to idle if all systems are normal the richer it is, as you lean it out, it will return slower.
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Seasoned HDF Member
Joined: Nov 2009
Posts: 15,705
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From: Farmington ,MS
Try cutting down the baffles instead of completely removing them. My 83 shovel with a brand new super e, comes back to idle slower than my 84 evo. it has electronic ignition...never understood why, but it gives it part of it's unique sound. If it is not really slow to come back, it is not a problem.
Thread Starter
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Cruiser
Joined: Apr 2012
Posts: 178
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From: Where our Gov. makes our license plates
If I remember right yes it ran like this before I removed the baffles. I got this bike last fall and only put a few miles on it before the weather went south.