Cutting Out

[fizzwheel]

My SV used to do that when the weather was cold. I turned the idle speed up a little so it idle'd around the 1400rpm mark and it cured it.

on my way home today, it didn't do it, funny enuf. I've looked at the idle speeds is jus a nats wisker over 1k for chole off and 4k fully choked.

could it be that have been leaving a bit of choke on? on the way home i warmed it up for a good 10-15 mins so it was running fine unchoked. and made a point of checking the choke was all the way off. and would you know it, i got home wiout the problem surfacing.

if this is true, why?

I thought (again I'M A NEWBIE!!!!) that the choke is used to warm the engine up, therfore if it's not warmed up and i've got to get off then a little bit of choke would help keep the engine warm.

[Dave20046]

I'd try turning the idle up to about 1.5k
Do you know where the adjust ment is? like a nob with a screwdriver slot in, below the frame on the left hand side of the bike.
Adjust it while switched on; turn it a little bit, give it a rev -see where it sits (and repeat).

Originally Posted by FlyinCustard

on my way home today, it didn't do it, funny enuf. I've looked at the idle speeds is jus a nats wisker over 1k for chole off and 4k fully choked.

could it be that have been leaving a bit of choke on? on the way home i warmed it up for a good 10-15 mins so it was running fine unchoked. and made a point of checking the choke was all the way off. and would you know it, i got home wiout the problem surfacing.

if this is true, why?

I thought (again I'M A NEWBIE!!!!) that the choke is used to warm the engine up, therfore if it's not warmed up and i've got to get off then a little bit of choke would help keep the engine warm.

Idle should be higher mate, adjust it as dave says giving it a rev after every twist just to make sure nothing is sticking and repeat until it idles at the needles width under the 1500 mark.

In simple terms the choke is used to warm the engine up.

Someone correct my understanding if im wrong but its not like a heater or anything all it does is adjust the mixture or air and fuel. Starving the engine of air causes the fuel to burn more aggressivly aiding the start up of the engine. Once started and running correctly (ie once the revs pick up) the choke needs to be turned off to allow air back in otherwise the fuel will bog the internals down an in effect it floods (cuts out). It will run if the choke is on but only if you have the throttle open and this is becuase using the throttle also opens the carb letting the necessary air in for the combustion.
Therefore you close the throttle the air burns out and it gets bogged down and cuts out again, giving the impression that its dying from lack of idle revs.

The 2 things I'd look at custard are; First to adjust your idle and see if this helps. If it doesnt then see if your choke cable is working correctly (from the reviews I read before I purchased mine the SV's are prone for choke jams/cables snapping).

Sounds like a pluger on your choke is sticking open when you close the choke fully off.

On second thoughts turn up your idle like mentioned and you should have no problems

ok, thanks leedsmatt7 i understand choke more now, and having a new under standing of use of the choke plus changing the idle speed hopefully will solve this little problem of mine.

Right changing the idle speed.

Current iddle speed with no choke

Originally Posted by Dave20046

I'd try turning the idle up to about 1.5k
Do you know where the adjust ment is? like a nob with a screwdriver slot in, below the frame on the left hand side of the bike.
Adjust it while switched on; turn it a little bit, give it a rev -see where it sits (and repeat).

Is this it?





Is this it?




Also what is this and why does it just end with nothing on it?




Also please tell me if the sound of my engine is normal, it seams to be knocking to me.
http://s39.photobucket.com/albums/e1...t=S5000007.flv

Please excuse the big writing im not shoutin i jus thort the pics made it difficult to see the writtin.
Thanks Again!!! every1 for all the help, its a massive help to a newbie like me.

[dizzyblonde]

Originally Posted by FlyinCustard

ok, thanks leedsmatt7 i understand choke more now, and having a new under standing of use of the choke plus changing the idle speed hopefully will solve this little problem of mine.

Right changing the idle speed.

Current iddle speed with no choke




should be 12-1500.



Is this it?




Thats your clutch cable.
Is this it?




THis is your idle adjustment. It pulls off the little tab, don't worry, you shouldn't break it

Also what is this and why does it just end with nothing on it?





Thats a breather hose.
Also please tell me if the sound of my engine is normal, it seams to be knocking to me.
http://s39.photobucket.com/albums/e1...t=S5000007.flv

Please excuse the big writing im not shoutin i jus thort the pics made it difficult to see the writtin.
Thanks Again!!! every1 for all the help, its a massive help to a newbie like me.

My big writing in btween your isn't shouting, just highlighting what the pics are

PS, your engine, sounds fine to me, can even hear the tick that mine has, thats not quite out of my hearing range. It is hard to say anything about a video, as sound isn't the best, but I've heard and felt worse knocking out of that side of my engine!

[dizzyblonde]

## Clymer/Haynes manual states idle speed should be set at 1300 +/- 100 ##

Ta dizzyblonde will report back when changed

[yorkie_chris]

Originally Posted by leedsmatt7

Idle should be higher mate, adjust it as dave says giving it a rev after every twist just to make sure nothing is sticking and repeat until it idles at the needles width under the 1500 mark.

In simple terms the choke is used to warm the engine up.

Someone correct my understanding if im wrong but its not like a heater or anything all it does is adjust the mixture or air and fuel. Starving the engine of air causes the fuel to burn more aggressivly aiding the start up of the engine. Once started and running correctly (ie once the revs pick up) the choke needs to be turned off to allow air back in otherwise the fuel will bog the internals down an in effect it floods (cuts out). It will run if the choke is on but only if you have the throttle open and this is becuase using the throttle also opens the carb letting the necessary air in for the combustion.
Therefore you close the throttle the air burns out and it gets bogged down and cuts out again, giving the impression that its dying from lack of idle revs.

The 2 things I'd look at custard are; First to adjust your idle and see if this helps. If it doesnt then see if your choke cable is working correctly (from the reviews I read before I purchased mine the SV's are prone for choke jams/cables snapping).

Petrol does not burn. Petrol VAPOUR burns.
Go and breath on something cold, see the condensation form? This is exactly what happens in the engine when it's cold.
So, the choke* gets around this by the simple expedient of dumping a load more fuel and a little more air in.
More fuel means there is more chance of enough of it being in vapour state to get a burn, more air means a higher idle speed and less time for the condensation to form. Not to mention some is required to effectively drag the fuel out of the carb.

*on the SV, it isn't a choke, it's an idle enrichment valve. A choke actually closes off the intake so more of the vacuum of cranking sucks fuel than air.

Is that 1k rpm idle speed when warm? I'd suggest a tad under 1500 as suitable. An underspeed engine will knock and bang about and generally whinge.