Waking from a 30 year slumber
I have stayed with the stock carb because i have always wanted my IronHead to be period correct with as much OEM equipment as possible. And i am less concerned about performance. I ride mostly by myself, and in that circumstance my bike is always the fastest on the road!
Installing a different carb is not just a simple bolt-on operation. It will stick out further and bump your knee if you have forward controls, and you cannot use the original air cleaner or the original carb support bracket. And you have to work out which jets etc will be best for your setup. It is a lot of hassle that i have not wanted to be bothered with.
The two most popular choices that i have seen are a used CV and the Mikuni VM38 ...
The CVs give the very best price : performance ratio. They are plenty and cheap on eBay, typically ~$75, certainly less than $100. And once tuned up they give excellent performance and gas mileage.
The VM38 needs no tuning runs - install following the factory directions and you are good to go; a bonus for kick start bikes as these are said to be one-kick carbs.
One of those would be my choice.
With the S&S carbs keep in mind that there are a few models, designated by a letter - B, E, G, shorty, whatever. These are not all appropriate for an IronHead. Be sure to research before deciding, and be sure to decide on a scientific basis, not just on what the believers say.
Here are some opinions ...
Best Carb for an IronHead
Installing a different carb is not just a simple bolt-on operation. It will stick out further and bump your knee if you have forward controls, and you cannot use the original air cleaner or the original carb support bracket. And you have to work out which jets etc will be best for your setup. It is a lot of hassle that i have not wanted to be bothered with.
The two most popular choices that i have seen are a used CV and the Mikuni VM38 ...
The CVs give the very best price : performance ratio. They are plenty and cheap on eBay, typically ~$75, certainly less than $100. And once tuned up they give excellent performance and gas mileage.
The VM38 needs no tuning runs - install following the factory directions and you are good to go; a bonus for kick start bikes as these are said to be one-kick carbs.
One of those would be my choice.
With the S&S carbs keep in mind that there are a few models, designated by a letter - B, E, G, shorty, whatever. These are not all appropriate for an IronHead. Be sure to research before deciding, and be sure to decide on a scientific basis, not just on what the believers say.
Here are some opinions ...
Best Carb for an IronHead
Tourer
Joined: Sep 2007
Posts: 400
Likes: 1
From: se ohio
unless you are running some wild stroker high comp. motor a s&s will be a waste of money, get a cv or a vm 38 tune it and ride the bike, i made the cv conversion a few years ago and have never looked back, i ride about 4000 miles a year, bike has never fouled a plug,never not started right up even after siting for a while, and i got the cv for 75$ plus the cost of a e-bay branch intake and a couple hand made carb supports
Tourer
Joined: Sep 2007
Posts: 400
Likes: 1
From: se ohio
unless you are running some wild stroker high comp. motor a s&s will be a waste of money, get a cv or a vm 38 tune it and ride the bike, i made the cv conversion a few years ago and have never looked back, i ride about 4000 miles a year, bike has never fouled a plug,never not started right up even after siting for a while, and i got the cv for 75$ plus the cost of a e-bay branch intake and a couple hand made carb supports i should say that my bike is .040 over 10.5 to1 and has a set of andrews r5 cams and a evo sporty cant even come close to touching me until i run out of gear lol
Thread Starter
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Cruiser
Joined: Oct 2011
Posts: 153
Likes: 0
From: Bellmawr NJ
I am 98% sure my carb issues are due to the larger float needle I put in from the rebuild kit. I am renewed with a mindset to stubbornly get the old carb working and not blow $500 on a carb that is more than I need. I found an awesome indie shop, Nicks Custom Cycles in Williamstown NJ, I am sure they will have something (parts or hands on help/advice) to help me out.
If you are from NJ and haven't been to Nicks, it's awesome! The 2nd floor is a museum with Harleys dating back to at least 1908. Lots of cool panheads, knuckleheads, a few K models and some military models with sidecars.
If you are from NJ and haven't been to Nicks, it's awesome! The 2nd floor is a museum with Harleys dating back to at least 1908. Lots of cool panheads, knuckleheads, a few K models and some military models with sidecars.
Remind us of what are the carb issues. We may have some good pointers.
Thread Starter
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Cruiser
Joined: Oct 2011
Posts: 153
Likes: 0
From: Bellmawr NJ
My 78 sportster will start, and idle just fine, runs OK with a minor hesitation when the throttle is jabbed but haven't really got into tuning it at all. The issue is that when the bike is idling / not moving forward it will die and puke gas from the overflow tube, and twice I saw it come from what looked like the air cleaner. If the bike is off and I turn the petcock on I get a trickle from the overflow.
I took the carb off today (stock keihin) and the needle will move up and down with the float. Mind you I replaced the original needle with a new one from an HD rebuild kit, and when I did that the tang on the float needed a lot of bending to get back to the right spec.
Another thing I noticed when taking the carb off/apart today that wasn't there last week when I rebuilt it. There is a yellow spot that has formed on the float itself. When I rub it the yellowish stuff will come off like fine dust.
I took the carb off today (stock keihin) and the needle will move up and down with the float. Mind you I replaced the original needle with a new one from an HD rebuild kit, and when I did that the tang on the float needed a lot of bending to get back to the right spec.
Another thing I noticed when taking the carb off/apart today that wasn't there last week when I rebuilt it. There is a yellow spot that has formed on the float itself. When I rub it the yellowish stuff will come off like fine dust.
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Stage II
Joined: Oct 2011
Posts: 2
Likes: 0
From: connecticut
Some great tips on here! I just bought a 79 XLS 1000 a few days ago and am also new with motorcycle mechanic. I plan to learn and do as much work myself as i can. As i was told it would.. some oil absolutely leaks. Not a crazy amount but enough that i want to stop it best i can. It is hard to tell exactly where it comes from even after wiping everything down. What would be some good first steps?