This is my first thread so id loke to start off by saying hello to everyone. I recently purchased a 2007 dyna street bob and it came with a kuryakyn hypercharger. First off my bike is having problems firing up. It will crank and crank and crank until it coughs and eventually will start after a few attempts. I have read a few forums and it sounds like it could be a vacuum issue but I'm not certain. Once the bike starts it runs fine. But 9/10 times it has trouble firing up. The butterflies stay wide open all the time. They aren't stuck because I'm able to move them with my fingers very easily. Any help is much needed.

 

Welcome to the forum.

The flaps on the Hypercharger, even the Hypercharger itself has nothing to do with the bikes performance, including how it starts. It's all just for show. (It should start instantly w/o the air cleaner taken completely off the manifold too.)

It sounds like it's not getting enough fuel. It's injected I assume. Is there a tuner or download installed that you know of?

 

cold start enrichment too lean, want to watch the screws on the two plates of the hypercharger know of two bikes that the screws came loose and where sucked into engine and damaged the piston and intake valve.

 

Yes it's carbureted and the dealer said it was supposedly dynoed but I have the feeling it wasn't. If it has nothing to do with the bikes performance than why does it have to be dyno tuned??

 

when a bike in dyno tuned, the fuel and timing are adjusted so the engine makes the best power and drivability. and is set for certain AFR per each tuners suggestions which make the best combination. I though 07 year bikes were EFI. than does your bike have a choke lever that you are not using to start with when cold.

 

Nah no choke lever. I'm guessing its something with the vacuum because the butterflies don't move and it's having trouble starting.

 

Ditch the hyper charger it is a total piece and after you replace let us know if you still have problems.

 

that breather assy just sets over the bore of the throttle body or carburetor
the vacuum line hooks to the intake for a vacuum source when you open the throttle plate the vacuum drops causing the hyper charger plates to open. has nothing to do with the starting of the engine. look at the intake form the other side of bike to see if you can see injectors in the intake manifold still believe o7 are efi.

 

There's no choke lever because I believe all 2007 dynas were injected.

The butterflies on the air cleaner are not functional.

The butterfly UNDER the air cleaner in the throttle body is probably closed, but you'll have to remove the Hypercharger and filter to see it move in conjunction with the throttle cable when you twist the grip.

You are going to have to learn something about your motorcycle or you are going to get screwed down the line.

Here you go:

General informationModel:Harley-Davidson FXDB Dyna Street Bob
Year:2007
Category:Custom / cruiser
Rating:77.5 out of 100. Show full rating and compare with other bikes
Price as new (MSRP):US$ 13595. Prices depend on country, taxes, accessories, etc.Engine and transmissionDisplacement:1573.25 ccm (96.00 cubic inches)
Engine type:V2, four-stroke
Torque:124.75 Nm (12.7 kgf-m or 92.0 ft.lbs) @ 3000 RPM
Compression:9.2:1
Bore x stroke:95.3 x 111.3 mm (3.8 x 4.4 inches)
Fuel system:Injection. Electronic Sequential Port Fuel Injection (ESPFI)
Cooling system:Air
Gearbox:6-speed
Transmission type,final drive:Belt
Clutch:Multi-plate with diaphragm spring in oil bath
Fuel consumption:4.43 litres/100 km (22.6 km/l or 53.10 mpg)
Greenhouse gases:102.8 CO2 g/km. (CO2 - Carbon dioxide emission)
Exhaust system:Chrome, staggered shorty dualsChassis, suspension, brakes and wheels
Rake (fork angle):29.0°
Front tyre dimensions:100/90-H19
Rear tyre dimensions:160/70-B17
Front brakes:Single disc
Rear brakes:Single discPhysical measures and capacities
Dry weight:287.6 kg (634.0 pounds)
Weight incl. oil, gas, etc:302.5 kg (667.0 pounds)
Seat height:681 mm (26.8 inches) If adjustable, lowest setting.
Overall length:2,357 mm (92.8 inches)
Ground clearance:142 mm (5.6 inches)
Wheelbase:1,631 mm (64.2 inches)
Fuel capacity:18.16 litres (4.80 gallons)Other specifications
Starter:Electric
Color options:Vivid black, black cherry pearl, deep cobalt pearl, black denim, Pacific blue denim (new), pewter denim (new), two-tone olive pearl and vivid black

 

I realize that the butterflies aren't functional performance wise. But when the intake is functioning properly they are supposed to open and close when bike is running and the throttle is twisted. Look up a video on YouTube. There are guys showing off their hyperchargers on dynas and the butterflies open and close. I should mention that when my bike has been running awhile it gives me the most trouble starting up. It pretty much turns right over when it's cold.