Rough Idle - with pics and video

[mumbles]

Hello again,

I have uploaded a video and pictures this time to help diagnose the problem which is a follows; you see at the start of the video (engine already warmed up) it has a very rough idle with the mixture screws quite far out (rich) and the idle speed screw quite far in. When I rev the bike it hangs at 3000rpm and if I drop the idle speed screw it idles normally but most times just stalls and if i go out for a ride with the idle speed screw that low it will stall at lights, rounder-bouts ect. so just a case of leaning out the mixture right? nope because it idles slower if I make the mixture leaner and stalls more often and it also makes if much harder to rev from idle.

Just to add compression on my bike is low 130psi but it's 130psi on both cylinders so it's irrelevant right? and their is a nose coming from the top end it's not tapping it just sounds like loud moving parts (Im not sure how to describe it better)

https://www.youtube.com/v/4_Rx-zpBQzM


https://i1054.photobucket.com/albums/s492/mumbles_8P/GOPR2011.jpg

https://i1054.photobucket.com/albums/s492/mumbles_8P/GOPR2012.jpg

https://i1054.photobucket.com/albums/s492/mumbles_8P/GOPR2013.jpg[/url][/code]
____________________
Warming the world 2 strokes at a time.

2008 rs50 (SOLD) - 2006 gz125 - (Winter Bike) - 1981 CB250N (In Restoration)

[Ollie1995]

First thing I'd do is buy some new plugs.
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XR 125, DT125 LC, Greeves Scottish, RS200, XS400, GPX600r

Theory Passed - 18/7/13 MOD1 Booked - 24/9/13

[mumbles]

[yen_powell]

Is the choke stuck on, cos those plugs look very sooty so it's running rich.

What bike are we talking about, does it have a cable choke or a plunger direct on the carb?
____________________
Blackmail is a nasty word........but not as nasty as phlegm!
XT1200Z and a DR350 in bits

[mumbles]

[WULFSTAN]

What condition is the air filter in
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Your backside is better enough for you to run again, if need be – bristle up the courage of the cornered rat, put on a bold front, and to hell with them. Bluff my boy – bluff, shift and lie for the sake of your neck and the honour of Old England

[mumbles]

[yen_powell]

[mumbles]

I have just realized what you mean by plunger, I don't have that type of choke my choke works on butterfly valves which I have removed completely
____________________
Warming the world 2 strokes at a time.

2008 rs50 (SOLD) - 2006 gz125 - (Winter Bike) - 1981 CB250N (In Restoration)

[mumbles]

It just occurred to me that I don't have the stock exhaust on this bike I have bolted on 2 125cc pit bike exhausts with I think are being more restrictive, could this cause the problems im having ?
____________________
Warming the world 2 strokes at a time.

2008 rs50 (SOLD) - 2006 gz125 - (Winter Bike) - 1981 CB250N (In Restoration)

[radicalrabit]

Can I ask why the fk do people mess with their bikes if they dont know what the fk they are doing or what effects its going to have?

is it TINKER management ?
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VF1000 F2F, BLACKBIRD with carbs, 2nd VF1000F2F just need somewhere to go now..

[R1stu]

Ive been having the same issues on my cb350. took the tank off yesterday and found the carbs were caked in crap around the choke mech. so when the choke was on, then turned off the lever went down, but the plunger was stuck in the on position.

This caused my bike to idle at 4k.

Cleaned it off with brake cleaner and wd40 and seems OK now.

Maybe something is gunked up sticking it.
____________________
Carbon closet tart! https://www.bikepics.com/members/r6stuk/02r6/
Stolen bike. 2000 R1: https://www.bikepics.com/members/r6stuk/00r1/
Current bike 1991 Honda ST1100 Pan European, 1986 Honda cb350sg (Finished)

[mumbles]

[R1stu]

[paddlesat16]

The cb250n or superdream needs a choke for the cold weather, I would suggest you put it back on

This will fix the cold starting. Buy a Haynes manual as this will stop you making stupid errors while owning the bike.

The air screws on the bottom of the carbs need to be set at 2 turns out from fully screwed in, your idle speed should be set at 1300 rpm+/- 100 with the black knob under the carbs.

Once set up the black plugs will disappear and a nice tan brown will magically appear.
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I once saw a bloke shagging a donkey.... in Saudi arabia. Theory Test Passed 26/10/09 Mod 1 Passed 26/4/10, Mod 2 Passed 7/6/10 Current Bikes Suzuki GSX1400 K5, Aprillia Pegaso 650, Suzuki DR350T.

[mumbles]

[mumbles]

[paddlesat16]

Balance the carbs first, this should cure the rough idle
____________________
I once saw a bloke shagging a donkey.... in Saudi arabia. Theory Test Passed 26/10/09 Mod 1 Passed 26/4/10, Mod 2 Passed 7/6/10 Current Bikes Suzuki GSX1400 K5, Aprillia Pegaso 650, Suzuki DR350T.