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07-14-2015, 07:53 AM,
#1
Vstar 1100 runs rough when cold
First of all sorry for my english :)
Hi! I have a problem with my bike. On cold starts, there is black smoke coming out of my exhausts and the bike wont idle if it dosent have full choke. If I take it right away it will run very rough and backfire a lot. I have custom exhausts and the carbs have been tuned last month. Ill check on the air filter and spark plugs when I get back from work I just wanted to see if anybody here has ever had the same issue.

This is only happening when the bike is cold. When its warm, it starts and drive like new.

Thank you very much
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07-14-2015, 09:21 AM,
#2
RE: Vstar 1100 runs rough when cold
does it still have the ais, if so disable or totally remove it since you have done the exhaust work. has any air intake work been done, if so with the exhaust would need those carbs rejetted.
2006 VStar Stratoliner, Freedom Performance split dual exhaust, Mustang seats, Sissy bar with back rack, bolted saddlebags to mounts.
Life's tough .. it's even tougher if you're stupid. - John Wayne

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07-14-2015, 10:20 AM,
#3
RE: Vstar 1100 runs rough when cold
When you say "cold start" how cold are we talking? If you just mean the first start of the day even in warm weather then there is definitely some issue with fuel, carbs, or spark. Black exhaust usually means rich fuel mixture or cold spark (it can also mean water in the fuel but that wouldn't be temperature sensitive). You might see what plugs are in it and check the gap. It could be a case of the plugs being too cold or having incorrect gap (or just being fouled) which could make the bike pretty balky until the head and piston heat up enough to help combustion.

If you're talking about in cold weather where the air temperature is 45 degrees (F) or lower it could be that the carb heaters are not working or you're not giving them time to work before starting. In cold weather put the bike in neutral, leave it on the side stand, turn the ignition on, and let it sit for about 30 seconds or so before trying to start. This gives the heaters time to do their job. Then, leave the bike in neutral on the side stand until it is running smoothly (one of the heaters is disabled by either the side stand switch or the neutral switch, I don't recall which at the moment) This makes a big difference in my 650 in cold weather.
===========================
2011 V-Star 650 Custom (new in fall 2013)
V&H Cruzer Pipes, Memphis Shades Bat Wing, Floorboards, Highway Bars,
Locking Bags, Tail Rack, LED Signals & Aux Brake Lights, Headlight Modulator,
Brake Light Modulator, 5/8" Gel Pad Under Upholstery.
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07-14-2015, 10:43 AM, (This post was last modified: 07-14-2015, 10:45 AM by LeDom.)
#4
RE: Vstar 1100 runs rough when cold
By cold start I mean first start of the day. Ais is deleted and I still have the factory air intake.

As soon as the engine is warm it runs fine. It's just that I dont want to let it run for 10 minutes in the morning and be unpleasant with my neighbors lol
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07-14-2015, 11:17 AM,
#5
Vstar 1100 runs rough when cold
What is your carb set up?
Needles, jets, pilots and pms
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07-15-2015, 10:20 AM,
#6
Vstar 1100 runs rough when cold
Problem solved! Changed the spark plugs and did a sea foam treatment. Thanks for the help!

[Image: 4f28f10afeefea595fdaaf36a3de98fc.jpg]

[Image: b8bae010f7ad560d09752eb80afee08b.jpg]
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07-15-2015, 10:56 AM,
#7
RE: Vstar 1100 runs rough when cold
Those plugs look pretty fouled - like the bike is running too rich - you may still need to adjust jetting or needles or you'll just foul the new plugs.
===========================
2011 V-Star 650 Custom (new in fall 2013)
V&H Cruzer Pipes, Memphis Shades Bat Wing, Floorboards, Highway Bars,
Locking Bags, Tail Rack, LED Signals & Aux Brake Lights, Headlight Modulator,
Brake Light Modulator, 5/8" Gel Pad Under Upholstery.
Reply
07-15-2015, 11:06 AM,
#8
RE: Vstar 1100 runs rough when cold
Guess that means Im going to have to change my plugs again this year after I get my carb situated.
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07-15-2015, 11:14 AM,
#9
RE: Vstar 1100 runs rough when cold
(07-15-2015, 10:56 AM)OldePhart Wrote: Those plugs look pretty fouled - like the bike is running too rich - you may still need to adjust jetting or needles or you'll just foul the new plugs.
How do you adjust this?
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07-15-2015, 11:41 AM,
#10
Vstar 1100 runs rough when cold
(07-15-2015, 11:14 AM)LeDom Wrote:
(07-15-2015, 10:56 AM)OldePhart Wrote: Those plugs look pretty fouled - like the bike is running too rich - you may still need to adjust jetting or needles or you'll just foul the new plugs.
How do you adjust this?

That's why I asked what how do you have your carb set-up....
Those plugs look fouled meaning you are running to rich, meaning your main jets are to big..... and the same problem it's going to happen to your new plugs pretty soon.
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07-15-2015, 11:43 AM,
#11
RE: Vstar 1100 runs rough when cold
I really don't know about my carb set up
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07-15-2015, 11:45 AM,
#12
RE: Vstar 1100 runs rough when cold
(07-15-2015, 11:14 AM)LeDom Wrote:
(07-15-2015, 10:56 AM)OldePhart Wrote: Those plugs look pretty fouled - like the bike is running too rich - you may still need to adjust jetting or needles or you'll just foul the new plugs.
How do you adjust this?
There are several "adjustments" - some of which involve replacing the jets with smaller ones, some involve adding or removing shims from the needle, and others involve adjusting the premixture screw. And then, of course, it's important that the carbs be synchronized. @Maustarman is probably our local expert on 650 and 1100 carbs. Myself...I despise working on carbs. :)
===========================
2011 V-Star 650 Custom (new in fall 2013)
V&H Cruzer Pipes, Memphis Shades Bat Wing, Floorboards, Highway Bars,
Locking Bags, Tail Rack, LED Signals & Aux Brake Lights, Headlight Modulator,
Brake Light Modulator, 5/8" Gel Pad Under Upholstery.
Reply
07-15-2015, 11:53 AM, (This post was last modified: 07-15-2015, 11:54 AM by Maustarman.)
#13
Vstar 1100 runs rough when cold
As @oldephart mentioned this can be one or a combination of things ... And your first step is pulling the carbs out to check what you have... Working from there you will also need a carb synch at the end
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07-15-2015, 02:59 PM,
#14
RE: Vstar 1100 runs rough when cold
Of course, that's a lot of trouble. You could just let it run crappy and people will think you have a Harley...oh, well, you probably need to spill a little oil under where you park it to make that believable... LOL

Just kidding, of course.
===========================
2011 V-Star 650 Custom (new in fall 2013)
V&H Cruzer Pipes, Memphis Shades Bat Wing, Floorboards, Highway Bars,
Locking Bags, Tail Rack, LED Signals & Aux Brake Lights, Headlight Modulator,
Brake Light Modulator, 5/8" Gel Pad Under Upholstery.
Reply
07-15-2015, 03:14 PM,
#15
RE: Vstar 1100 runs rough when cold
Lolol I will check the carbs as soon as I have the time. In the meanwhile is it dangerous for the engine or not at all?
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