Mikuni
- Thread starter JoeSRV
- Start date
A sitter with gas left in the carb now evaporates, leaves a mess in the carb. That says 3 circuits are needed to even start and idle. So the question is, does it start as if one kick, idles and does not hunt, but steady.
Either NAPA for 12 bucks and 20min soaking in carb dip, or 3 bucks worth of vinegar and wait a few days. All rubber removed of course.
I'd take the challenge of a cleaning before I'd give up to another carb setup. Besides, where are we at with the Y fitting and those rubber rings from head to Y of that intake manifold? Lean pop sputter is air intake there before the carb. Vac acts like E... finds the shortest path.
Either NAPA for 12 bucks and 20min soaking in carb dip, or 3 bucks worth of vinegar and wait a few days. All rubber removed of course.
I'd take the challenge of a cleaning before I'd give up to another carb setup. Besides, where are we at with the Y fitting and those rubber rings from head to Y of that intake manifold? Lean pop sputter is air intake there before the carb. Vac acts like E... finds the shortest path.
T
Thank you. Yes, it starts up fine. the idle varies once it is warmed up. We'll try to clean before I consider a replacement.
mleach72
Well-Known Member
Yeah, the mikuni will work great. I've been using them for about 15 years now. I have a 42 on my harley and a 45 on my pitbull. The fuel mileage and throttle response can't be beat. They will work pretty well out-of-the-box, but the cruise zone is rich from the factory. To get it dialed in requires some trial and error with the pilot jet and needle, but once tuned, it will feel like fuel injection.
Mikeinjersey
Well-Known Member
Welcome from NJ,
Your carb is more than likely clogged up from the old gas. Pull the bowl and clean the jets and float valve. Caution: do not loose or forget to reinstall the ejector valve O-Ring. If that doesn't work give the carb a more complete cleaning as Sven suggested. As an added bonus it will give you an opportunity to see which jets are installed. S&S and Mikuni are both quality choices.
Your carb is more than likely clogged up from the old gas. Pull the bowl and clean the jets and float valve. Caution: do not loose or forget to reinstall the ejector valve O-Ring. If that doesn't work give the carb a more complete cleaning as Sven suggested. As an added bonus it will give you an opportunity to see which jets are installed. S&S and Mikuni are both quality choices.
john sachs
Well-Known Member
S&S carbs are easier to tune, and modify. Mikuni's are a little tougher to dial in, and there's NO reason to modify them, as they offer 3 different bore sizes. 1 thing with a Mikuni that gets missed by the first timers, is the choke pin. You need to use the 1 that comes with the carb not a stock CV Harley choke pin. Also you'll need a bracket to hold the choke cable, An air cleaner adaptor, for bolt on air cleaners, and you will also need a manifold. The Mikuni manifolds are power losers( the short turn at the carb entrance is HORRIBLE). Power wise, size for size, they're about equal, with a good intake manifold for the Mik.
John
John
mleach72
Well-Known Member
To add to John's post, yes, you must use the Mikuni choke plunger and spring, but you may use a harley cv choke cable. You just need to transfer the mikuni plunger and spring to the cv cable. If doing this, use the harley choke nut, not the mikuni nut. This is probably unneeded info though. I'm pretty sure most 45 and 48 carbs come with a mikuni choke cable. The 42 comes without one, but it is a little too small for the 107's and 117's anyways.
The mikuni air cleaner adapter is universal. It allows mounting of any CV or S&S air cleaner. However, if you are using the stock S&S backing plate, you will need to file a small area to allow the throttle return arm to pass by the backing plate.
You CAN use your stock G manifold. Mikuni makes a rubber boot that bolts to the manifold. The spigot on the carb will then push into this boot and is tightened with a hose clamp. The other alternative is to use a Screamin' Eagle manifold. It is a spigot-type manifold. The carb simply pushes into the seal on the manifold.
You will most likely need to change throttle cables as well. Mikunis use cv style throttle cables and can't be adapted to S&S butterfly style cables. Most big dogs have S&S cables. I have seen some with cv cables though. If you have S&S cables, your carb will have a short cable guide. If you have cv cables, the cable guide will be tall.
The mikuni air cleaner adapter is universal. It allows mounting of any CV or S&S air cleaner. However, if you are using the stock S&S backing plate, you will need to file a small area to allow the throttle return arm to pass by the backing plate.
You CAN use your stock G manifold. Mikuni makes a rubber boot that bolts to the manifold. The spigot on the carb will then push into this boot and is tightened with a hose clamp. The other alternative is to use a Screamin' Eagle manifold. It is a spigot-type manifold. The carb simply pushes into the seal on the manifold.
You will most likely need to change throttle cables as well. Mikunis use cv style throttle cables and can't be adapted to S&S butterfly style cables. Most big dogs have S&S cables. I have seen some with cv cables though. If you have S&S cables, your carb will have a short cable guide. If you have cv cables, the cable guide will be tall.
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