Carb SV Cutting out at idle when warm. - SV650.org

07-06-12, 08:46 PM

Had my SV a couple of weeks, Had been sat for a while previously. Its a '00 SV650S. I've had a quick search but couldn't find anything with the same symptoms

Right from the start taking it to the MOT, when warm, pull the clutch in or stop and let the bike idle and it cuts out, Only when warm, when cold it has no problem idleing, even off choke.

Carbs have been cleaned, Bike has done around 800 miles in my ownership and the problem hasnt got better or worse (Not that I thought it would).

Its just like when you pull up, revs drop to idle and its like the kill switch has been flicked. Starts straight back up afterwards, and doesn't die if you pull the choke on a little or hold the revs up.

Any help would be great.

Thanks in advance.

flymo · 07-06-12, 09:38 PM

dirty carbs (most likely in my view), incorrect float levels, incorrect idle. vaccum leak somewhere (looked for cracked or perished hoses/mounting rubbers)

Sid Squid · 07-06-12, 11:26 PM

Sticking choke plunger.

embee · 08-06-12, 12:09 AM

As they say above, also what is the basic idle speed set at when it will idle? Should be 1300rpm or thereabouts, some people prefer slightly higher (1400).

If it'll idle when cold but not hot it tends to suggest overly rich mixture (as you get with sticky choke plunger).

flymo · 08-06-12, 06:46 AM

Quote:

Originally Posted by Sid Squid

Sticking choke plunger.

Good call, didn't think of that.

08-06-12, 04:39 PM

Cheers guys, Will go through the suggestions.

Don't think it has any air leaks, Ive sprayed some cleaner stuff without any rev increase/decrease and I've replaced the vacuum hoses along with a couple of the fuel hoses.

It idles around 1300 I'd say. Messed around with the idle screw, although it messes about. Noticed it misfires once, then twice, then cuts out, So does make me believe its carbs rather than ign like I was originally thinking.

Is there any other symptoms of a sticking choke plunger, The choke seems to work ok, I'll give it a go anyway. Any reccommended way to clean it?

Cheers very mucho.

20-06-12, 02:18 PM

Just to update this thread.

Pulled the choke plungers and they were fine.

Put new plugs in and it solved the issue for a few days, so now believe its a weak spark.

I'm going to try some new coils on it unless anybody can suggest anything else.

Very late edit, if somebody else finds thread, new coils fixed it

07-06-12, 08:46 PM	#1
AlexW Guest Posts: n/a	Carb SV Cutting out at idle when warm. Had my SV a couple of weeks, Had been sat for a while previously. Its a '00 SV650S. I've had a quick search but couldn't find anything with the same symptoms Right from the start taking it to the MOT, when warm, pull the clutch in or stop and let the bike idle and it cuts out, Only when warm, when cold it has no problem idleing, even off choke. Carbs have been cleaned, Bike has done around 800 miles in my ownership and the problem hasnt got better or worse (Not that I thought it would). Its just like when you pull up, revs drop to idle and its like the kill switch has been flicked. Starts straight back up afterwards, and doesn't die if you pull the choke on a little or hold the revs up. Any help would be great. Thanks in advance.

07-06-12, 09:38 PM	#2
flymo Member Mega Poster Join Date: Jan 2008 Location: North West Posts: 3,124	Re: Carb SV Cutting out at idle when warm dirty carbs (most likely in my view), incorrect float levels, incorrect idle. vaccum leak somewhere (looked for cracked or perished hoses/mounting rubbers)

07-06-12, 11:26 PM	#3
Sid Squid No, I don't lend tools. Mega Poster Join Date: Jul 2003 Location: Skunk Works, Nth London Posts: 8,680	Re: Carb SV Cutting out at idle when warm Sticking choke plunger. __________________ If an SV650 has a flat tyre in the forest and no-one is there to blow it up, how long will it be 'til someone posts that the reg/rec is duff and the world will end unless a CBR unit is fitted? A little bit of knowledge = a dangerous thing. "a deathless anthem of nuclear-strength romantic angst"

08-06-12, 12:09 AM	#4
embee Member Mega Poster Join Date: Jul 2003 Location: Warwickshire Posts: 2,802	Re: Carb SV Cutting out at idle when warm. As they say above, also what is the basic idle speed set at when it will idle? Should be 1300rpm or thereabouts, some people prefer slightly higher (1400). If it'll idle when cold but not hot it tends to suggest overly rich mixture (as you get with sticky choke plunger). __________________ "Artificial Intelligence is no match for natural stupidity"

08-06-12, 04:39 PM	#6
AlexW Guest Posts: n/a	Re: Carb SV Cutting out at idle when warm. Cheers guys, Will go through the suggestions. Don't think it has any air leaks, Ive sprayed some cleaner stuff without any rev increase/decrease and I've replaced the vacuum hoses along with a couple of the fuel hoses. It idles around 1300 I'd say. Messed around with the idle screw, although it messes about. Noticed it misfires once, then twice, then cuts out, So does make me believe its carbs rather than ign like I was originally thinking. Is there any other symptoms of a sticking choke plunger, The choke seems to work ok, I'll give it a go anyway. Any reccommended way to clean it? Cheers very mucho.

20-06-12, 02:18 PM	#7
AlexW Guest Posts: n/a	Re: Carb SV Cutting out at idle when warm. Just to update this thread. Pulled the choke plungers and they were fine. Put new plugs in and it solved the issue for a few days, so now believe its a weak spark. I'm going to try some new coils on it unless anybody can suggest anything else. Very late edit, if somebody else finds thread, new coils fixed it Last edited by AlexW; 29-04-13 at 07:21 PM.

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