Idles Differently
Stellar HDF Member
Joined: Sep 2020
Posts: 2,436
Likes: 2,883
From: Southeast
Agreed. Try the idle adjustment. If that doesn't fix the idle issue, then a good cleaning should do wonders. I'd definitely keep the carb you've got. 
Road Master
Joined: May 2018
Posts: 783
Likes: 179
From: Bay Area
When you say adjust the idle, you are adjusting the idle speed right, not the idle mixture? No adjustments on a carb, with the exception of the idle speed, should be made unless the bike is hot/up to normal temp. A 15-20 mile ride should be enough. If it still wont idle after that, turn the idle speed up a bit to keep it running and set the idle mixture then re adjust the idle speed. Theres plenty of videos on youtube on how to do that. Altitude wouldnt be a factor here (not enough change) but temp/humidity could play a part of the idle mixture if different. It could also use a good cleaning too due to age. While Id normally recommend a Mikuni 42 if youre looking to change, tuning those can be overwhelming if you arent a wrench and in this case isnt "needed" so Id agree with others in staying with the CV for now, just check the diaphragm or rebuild altogether.
Grand HDF Member
Joined: Apr 2007
Posts: 3,727
Likes: 3,073
From: Brighton, MI
I'm with the guys who are saying pull the carb and give it a once over.
I also agree with changing the intake seals even if just on principle. They are old, can get brittle with time and leak air causing the symptom you describe. Just do a little reading first because there is a little positioning of the manifold and carb knowledge that is needed when replacing. Not a big deal, just something to be aware of. Toss the old manifold bolts and install new 12 point 5/16-18 x 3/4" bolts. Will make your life easier.
The carb really does not need a ton of parts. Watch some youtube videos on rebuilding and make notes. Keep it mostly stock for now. Of course clean it. All holes and passages are suspect. Especially if bike has sat with ethanol fuel for a while. Look for worn needle and worn needle seat, check specs like float height and inspect float needle. The accelerator pump diaphragm is a common replacement part but watch some videos and proceed with caution so you don't lose small parts. The needle jet is commonly installed upside down by mistake so take some pics. Also the idle mix screw has a really small rubber O-ring that often stays stuck in the bore. It is in there and you need to fish it out.
Point is, give it a once over. It is due and can't hurt. Just takes a little time. Do you have a repair manual for this bike? If not, get one. A aftermarket manual download is better than nothing but the factory manual is hard to beat.
I also agree with changing the intake seals even if just on principle. They are old, can get brittle with time and leak air causing the symptom you describe. Just do a little reading first because there is a little positioning of the manifold and carb knowledge that is needed when replacing. Not a big deal, just something to be aware of. Toss the old manifold bolts and install new 12 point 5/16-18 x 3/4" bolts. Will make your life easier.
The carb really does not need a ton of parts. Watch some youtube videos on rebuilding and make notes. Keep it mostly stock for now. Of course clean it. All holes and passages are suspect. Especially if bike has sat with ethanol fuel for a while. Look for worn needle and worn needle seat, check specs like float height and inspect float needle. The accelerator pump diaphragm is a common replacement part but watch some videos and proceed with caution so you don't lose small parts. The needle jet is commonly installed upside down by mistake so take some pics. Also the idle mix screw has a really small rubber O-ring that often stays stuck in the bore. It is in there and you need to fish it out.
Point is, give it a once over. It is due and can't hurt. Just takes a little time. Do you have a repair manual for this bike? If not, get one. A aftermarket manual download is better than nothing but the factory manual is hard to beat.
Thread Starter
|
6th Gear
Joined: Jul 2025
Posts: 11
Likes: 0
From: Iowa Park, TX
I'm with the guys who are saying pull the carb and give it a once over.
I also agree with changing the intake seals even if just on principle. They are old, can get brittle with time and leak air causing the symptom you describe. Just do a little reading first because there is a little positioning of the manifold and carb knowledge that is needed when replacing. Not a big deal, just something to be aware of. Toss the old manifold bolts and install new 12 point 5/16-18 x 3/4" bolts. Will make your life easier.
The carb really does not need a ton of parts. Watch some youtube videos on rebuilding and make notes. Keep it mostly stock for now. Of course clean it. All holes and passages are suspect. Especially if bike has sat with ethanol fuel for a while. Look for worn needle and worn needle seat, check specs like float height and inspect float needle. The accelerator pump diaphragm is a common replacement part but watch some videos and proceed with caution so you don't lose small parts. The needle jet is commonly installed upside down by mistake so take some pics. Also the idle mix screw has a really small rubber O-ring that often stays stuck in the bore. It is in there and you need to fish it out.
Point is, give it a once over. It is due and can't hurt. Just takes a little time. Do you have a repair manual for this bike? If not, get one. A aftermarket manual download is better than nothing but the factory manual is hard to beat.
I also agree with changing the intake seals even if just on principle. They are old, can get brittle with time and leak air causing the symptom you describe. Just do a little reading first because there is a little positioning of the manifold and carb knowledge that is needed when replacing. Not a big deal, just something to be aware of. Toss the old manifold bolts and install new 12 point 5/16-18 x 3/4" bolts. Will make your life easier.
The carb really does not need a ton of parts. Watch some youtube videos on rebuilding and make notes. Keep it mostly stock for now. Of course clean it. All holes and passages are suspect. Especially if bike has sat with ethanol fuel for a while. Look for worn needle and worn needle seat, check specs like float height and inspect float needle. The accelerator pump diaphragm is a common replacement part but watch some videos and proceed with caution so you don't lose small parts. The needle jet is commonly installed upside down by mistake so take some pics. Also the idle mix screw has a really small rubber O-ring that often stays stuck in the bore. It is in there and you need to fish it out.
Point is, give it a once over. It is due and can't hurt. Just takes a little time. Do you have a repair manual for this bike? If not, get one. A aftermarket manual download is better than nothing but the factory manual is hard to beat.
HDF Community Team
Joined: Dec 2005
Posts: 5,428
Likes: 2,623
From: NC USA
A Factory Service Manual will not help you with any carburetor issues other than setting the float height.
Last edited by t150vej; Aug 5, 2025 at 12:41 PM.
Seasoned HDF Member
Joined: May 2008
Posts: 21,176
Likes: 12,753
From: South Carolina
Remove carburetor, disassemble and clean.
Clean petcock screen.
Replace fuel hoses.
Replace intake seals.
This should be done every 22 years.
Clean petcock screen.
Replace fuel hoses.
Replace intake seals.
This should be done every 22 years.
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Thread
Thread Starter
Forum
Replies
Last Post
Mikedee
Touring Models
6
Oct 22, 2017 12:21 PM