A few questions from a complete newbie!

[SierraWhisky]

Hi guys,

I'm new to the forum and riding, having just completed my CBT and bought a Suzuki GS 125 ESM. I'm wanting to give maintaining my own bike as far as reasonably possible ago, I fancy the challenge! I've ordered the Haynes manual for the bike, but in the mean time I was hoping somebody might be able to answer a question for me:

https://www.dropbox.com/s/idcyhbwxj1wccnj/2012-11-26%2015.55.54.jpg

The link goes to a picture of what I assume is the clutch in the open position (extra fuel going in?!?). When I leave it to idle in this position the bike sits at about 3000rpm. When I close the choke the revs drop down blow 1000rpm and the engine cuts out.

I've tried leaving the engine running with the clutch open for 10 minutes so its warm and then closing the choke, but I still get the same problem.

Any suggestions?

Thanks

SW
____________________
Suzuki GS 125 ESM (1996)
Complete and utter novice.... but I will get the hang of this!

[snikks]

In the spirit of checking simple things first, is the idle set properly? There's usually a screw of some sort you can twist to make it idle slower or faster, your haynes manual should have details.

If that doesn't seem to help, it may be worth posting it in workshop, as that's where the real mechanics gurus hang out.
____________________
- CBT: 02/01/11 Theory: 26/04/11 Mod 1: 19/05/11 Mod 2: 19/08/11
- 2007 Honda XL125V Varadero (Sold), 1999 Yamaha FZS600 Fazer (Sold), 2001 CBR600F

[andy_uk]

Could be a few things...Someone more knowledgeable than me will probably be along shortly, but here are my suggestions :
1) Could be the mixture settings that need looking at
2) Air filter blocked or 'leaking' too much air through
3) Compression could be too low

Can you keep it running by blipping the throttle?
If so, does it ride ok or does it feel underpowered?


//edited to add :
The tickover adjuster is the screw just to the left of where it says "made in Japan" in the photo. Clockwise will increase the tickover.
____________________
Aprilia Classic 125, GS500E, ER5-A1, ER5-C4, ER6 & an XJ6 project frame...

[SierraWhisky]

Thank you for the replies so far!

I'll have a tinker with the screw in the light tomorrow. Like I said, complete novice, is it just a case of making minute adjustments until it'll tickover without stalling?

With the choke closed, I can blip the throttle to keep the engine running, and the bike feels like it's pulling away fine!

Appreciate the help.

SW
____________________
Suzuki GS 125 ESM (1996)
Complete and utter novice.... but I will get the hang of this!

[andy_uk]

The idle speed (tickover) should be 1,500rpm
____________________
Aprilia Classic 125, GS500E, ER5-A1, ER5-C4, ER6 & an XJ6 project frame...

[SierraWhisky]

[andy_uk]

That's for a fully warmed up engine, with the choke closed.
There's no set figure for while the choke is open.
Best way is to start it up (with choke if needed), have a ride around (close the choke after about a minute, or less if you can) until it's fully warmed up, then adjust the tickover screw until it's at 1,500rpm
____________________
Aprilia Classic 125, GS500E, ER5-A1, ER5-C4, ER6 & an XJ6 project frame...

[Teflon-Mike]

OK, that is a CV carb by the look of it, and that lever thingy on the side you show in pic, looks like the the throttle butterfly, not the choke, or even the clutch - your use of terminology suggests that you didn't quite grasp everything you should have covered in CBT....

CLUTCH: lever on the left hand handle-bar, operates a 'switch' in the transmission, that engages and dissengages drive. More like a 'dimmer-switch' than an on/off switch, you can gain partial drive, teh clutch 'slipping' between fully dissengaged & fully engaged... remember the biting point.

CHOKE: Mechanism for 'enritching' the mixture during cold-start. Name coming from old fasioned method of 'choking' the flow of air into the engine, originally with a hand over the intake, more conventionally via some sort of flap that closes the air-way.

Confusingly, a 'choke' in engineering terms can also be a restriction in a duct, and on some carburettors, such a restriction is fitted inside the carburettor to create a pressure drop and an increase in air-speed to help suck fuel into the air-stream. Most common on slide-less carburettors, such as a webber or delorto, which are often rated by 'choke size'.... but this sort of 'choke' ought not be confused with the enritchement mechanism.

THROTTLE: mechanism for controlling air-flow into the engine, and hence power.

On a conventional slide carb, a slide acts like a port-cullis in the air-way, exposing more or less area for flow, worked directly via a cable that pulls it 'up' to allow more air-flow, and a spring that pulls it back down again.

On your carb, a CV carb, you still have a slide, but instead of being worked directly by cable and spring, its lifted and lowered by a pressure differential above and below a diagphram.

The 'Throttle' as connected to the twist grip on the right hand throttle, works a butterfly valve upstream, by the looks of it, on your carb, which allows a more or less air-flow, and changes the pressure difference upstream and down stream of it, which lifts of lowers the main throttle slide, that self adjusts to maintain a 'constant velocity' of air-flow through the carb and hence a more constant vacuum above the main jet, and hence consistent mixture strength.

NOW, backing up to your 'problem'.....

[SierraWhisky]

Teflon,

Thanks for the reply!

I think the mix-up in terminology and perhaps in what I'm trying to say is due to a lack of sleep rather a lack of understanding (just come off nights), I hope!

When I've written clutch, I meant choke.

What I'm asking broken down is:

- Is the lever in the picture the choke?
- In the position that the lever is in on the picture, the engine will idle at 3000 rpm.
- If I move the lever 90 degrees downwards (only way it will go) the revs drop and the engine cuts out after approx 5 seconds.
- assuming if this is the choke, do I need to alter the idling speed?

You may have answered this and I've completely missed it, but I'm 30 hours without sleep and still got to stay up for a while longer, so I apologise if I have!

SW
____________________
Suzuki GS 125 ESM (1996)
Complete and utter novice.... but I will get the hang of this!

[Werny]

[SierraWhisky]

Ta muchly!
____________________
Suzuki GS 125 ESM (1996)
Complete and utter novice.... but I will get the hang of this!

[SierraWhisky]

Ok, so had a play with the screw as suggested, nothing really happened. Decided to ride it to my local bike shop and see what they said, just down the road the bike conks out and won't restart - battery completely flat!

Wheeled the bike to the shop, new battery bought and replaced, and idling speed sorted!

Thanks to everyone for their suggestions!

SW
____________________
Suzuki GS 125 ESM (1996)
Complete and utter novice.... but I will get the hang of this!