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Tire Wheel Fuel tank Vehicle Automotive fuel system


Hard to start and rough running. If you can keep it going for 5 to 10 miles it finally blows out enough carbon to run well. I've been reading in here about an idle knob I need to find and try but I have to wonder if it's the Cobra after market pipes as well. No or little back pressure and I really want a stock set of pipes. Sounds nice but louder than my preference. I thought the 2010 models had EFI and not carbs. Any addition advice is welcome. And yep, showroom above, just bought Saturday, the 21st.
 

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View attachment 260180

Hard to start and rough running. If you can keep it going for 5 to 10 miles it finally blows out enough carbon to run well. I've been reading in here about an idle knob I need to find and try but I have to wonder if it's the Cobra after market pipes as well. No or little back pressure and I really want a stock set of pipes. Sounds nice but louder than my preference. I thought the 2010 models had EFI and not carbs. Any addition advice is welcome. And yep, showroom above, just bought Saturday, the 21st.
All vn900's have EFI don't they !
 

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2010 Vulcan 900 Classic LT VN900BA
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View attachment 260180

Hard to start and rough running. If you can keep it going for 5 to 10 miles it finally blows out enough carbon to run well. I've been reading in here about an idle knob I need to find and try but I have to wonder if it's the Cobra after market pipes as well. No or little back pressure and I really want a stock set of pipes. Sounds nice but louder than my preference. I thought the 2010 models had EFI and not carbs. Any addition advice is welcome. And yep, showroom above, just bought Saturday, the 21st.
I have a 2010 and it’s definitely EFI. Have you checked your air filter? Mine had a mouse nest in it and had similar problems.
 

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Unfortunately it is all too common for dealers to take bikes in, not look at them, and stick them on the floor. It could be any number of things but is likely a dirty throttle body. Pull the intake cover, the air filter, then the back plate. Get some throttle body cleaner and spray the crap out of it. Get it started and running a few, then spray more while keeping it running. Short burst followed by a revs. By the time you’re done, the can should be empty. Top it off with fuel and then Measure out the proper amount of sea foam for 5 gallons to add to the tank. My guess is that will likely do it. You won’t be able to set the idle correctly until you can get it running smoothly. Yes..if the bike does not have a tuner or modified ecu, the open pipes can cause a lean condition (along with the likely installed k&n filter. I would check the bike over the same as if I bought it out of a barn.
 

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Idle knob is on the side of the air cleaner. Pipes alone wont cause the problem you are describing.
Throttle body is a possibility for sure.
Depending on mileage may be WAY over due for valve clearance check.
Bad fuel or clogged fuel filter
Clogged air filter
Bad plug wires or plugs that are so mucked up that they are not getting hot enough to stay clean until engine is at full operating temp.

Need a lot more information
Some people turn the idle knob down to get the bike to sound more like a Harley (this is a bad thing for these bikes) They are not Harleys and if they are not idling at the proper speed then the top end will not be getting the lubrication it needs and this will cause damage
 

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PS. You will find the idle control knob when you pull the air cover. What Plee said. I didn’t mean to imply the pipes are causing what you’re describing. Only that less restriction on both intake and exhaust side will cause it to run just slightly off the factory air/ fuel ratio. Hopefully it is just the throttle body and you should start there when checking it over. Get back to us with more info if that does not work.
 

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could also be bad battery. Low voltage barley able to start bike take a little bit to get voltage up high enough for the bike to smooth out and run right.
Seen these bike do all kinds of weird stuff when battery, stator or regulator are going bad. Check battery voltage and load test it for sure.
Pull the plugs and clean the heck outta them or replace them.
Give us all the information you can and we will do what we can to help you get it running the way it should.
these are great bikes and not prone to many problems
 

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Discussion Starter · #10 ·
Thank you all. Weather here is not going to let me do a full check at this time but I'll take your advice and start there. Bike is a 2010 but only 12,511 miles so it set up a lot and a long time.
 

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You might try some injector cleaner/fuel stabilizer in your next tank of gas - it might not fix your current woes, but it'll stop the issue from being compounded.
And black to me says rich mix - I know that your bike is EFI, so check the air filter and then whatever sensors your model/year comes with.
...and I agree with you about too much of a good thing with the aftermarket pipes, not my thing either.
 

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There is no manual choke on our bikes. The throttle body behind the air cleaner has 2 separate sets of round plates called butterflies.
The inner set closest to the motor is controled by the throttle. The outer set or secondary butterflies are controlled by a little arm that I believe is vacuum operated and actuates based on heat and throttle position.
The main reason some people remove them is because when you do the throttle becomes more responsive and doesn't have the slight delay and slower pick up when the throttle is twisted.
The down side of doing this is that if your grip and ability to hold throttle possition are not consistent or your on bumpy road this can lead to the bike feeling a bit jerky.

It also reduces restriction in your intake a little but nothing like a good after market intake will.

the system is pretty simple so if its failing to operate correctly then its usually a sign of a different problem and not the problem itself.
 

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I am not sure about this because I havent had a Nomad in Years. but just bought another one. After many years on a road king I finally saw the light and came back. There is a "choke" beside the key but it really isnt a choke. its a high idle that will go in all by itself after the engine starts. I always make sure it goes back in after the bike warms up some. (I think).
 
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