Harley YOST MIKUNI HSR 42 / 45
Carb Power Tube Kit *NEW*
Ultimate in State of the Art
High Performance Fuel Systems for Harley
Brand-new, direct from factory YOST Power Tube Kit for MIKUNI HSR 42 and HSR 45 Carburetors.
Just like the other Yost Power Tubes, the Yost Pro Power Tube for Mikuni, by design, produces a very fine mist. This very fine mist allows the fuel to stay in suspension longer for better control of air and fuel mixtures and can be almost perfectly matched for any throttle position.
You can expect an increase of up to FIVE H.P., improved mid range performance, and an incredible throttle response that will be sure to impress.
The Yost Power Tube Kit comes complete with the Yost Power Tube, 165, 170, 175, 180, and 185 main jets, rubber washer and the Yost Float Bowl Drain Nut. The main jets in this kit are interchangeable with stock H-D CV main jets and can be purchased at any OEM or any aftermarket dealer.
Yost part number is PT4 / HSR.
RETAIL $56.95
YOST POWER TUBE BENEFITS:
1. Produces a very fine mist
The Yost Power Tubes by design, produce a very fine mist, finer than most production fuel
injection systems and can be seen and observed by removing the air cleaner and looking into
the carburetor venturi.
2. Mid-Range Power and Horsepower
One of the Yost Power Tubes greatest benefits is extremely good PART THROTTLE response and
MID-RANGE performance. This is the most affordable horsepower gain that money can buy.
Typically, there will be an increase of 2-5 horses.
3. Increased Combustion Efficiency
The Yost Power Tube provides increased combustion efficiency for a more complete burning of the
fuel mixture so that you need less fuel to do the same job. The Yost Power Tube is specifically
designed to synchronize the engine demand with the air and fuel requirements. (In other words,
this Yost Power Tube gives you the proper amount of fuel at just the right time.)
4. Smoother Running Engine
You will have a smoother running engine through the entire range, due in large part to the
increased combustion efficiency. There is a greatly reduced possibility of pockets of raw
fuel burning randomly.
5. Detonation
In your combustion chambers, and again because of greater combustion efficiency, the
possibility of detonation is also reduced. We have never ridden in scientifically or
atmospherically ideal conditions, so I would still be somewhat conservative with compression
ratios and ignition timing.
6. Reduced Possibility of Part Throttle Lean Spot
This means that ideally you can use a larger carburetor, bigger ports, and more aggressive
camshafts with a reduce possibility of a part throttle lean condition. (smaller fuel particles
are easier to move and lift than larger particles) but use some wisdom and remember that if
you set up a street engine to DRAG specifications, you may have drivability problems at lower
engine speeds.
7. Shorter Warm-up & Reduced Spark Plug Fouling
Most riders also experience shorter warm-up times and a reduced possibility of spark plug
fouling. With increased efficiency, the additives present in gasoline are more completely
burned, so much so that it is difficult to leave residue deposit on the spark plugs.
8. Jetting For Atmospheric Conditions
Providing that your jetting is fairly close to the atmospheric conditions that you are riding
in, your engine will run cooler. This can be checked with a thermometer in your oil bag.
9. Surges & Flat Spots
The Yost Power Tube is designed to almost completely eliminate surges and flat spots by
controlling air-fuel mixtures more precisely, and provides an almost unbelievably smooth
throttle response and carburetor circuit transition.
10. Easier To Start The Main Fuel Circuit
With the Yost Power Tube installed, it is much easier to start the main fuel circuit,
while needing less manifold vacuum to do so.
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