Tick over problem

[Hammer]

Hi,

Just rebuilt a series 3 Li 125 with a casa 185 kit, scootopia 22m carb and varitronic igintion. All runs fine and kicks over almost first kick but I cant get it to tick over. The tick over screw is fully wound in but still wont tick over. Any ideas please.

[MK Monty]

When you say tick over screw are we talking about the one that lifts the slide by pushing against the throttle arm. If so I expect it's like the Jetex version that often needs the little flap bending down a bit to meet the screw. That should give you more range to get it ticking over. If you are talking about the air screw on the side of the carb it's not used for this purpose. Screw it all the way in then back 1 to 11/2turns and try and find the sweet spot. If I'm off the mark please forgive me.

[Hammer]

Yes the one pushing against the throttle arm. Is this a common problem then?

[MickYork]

alternatively.........choke not closing fully, pilot too big, ignition too far retarded.....others to follow

[missing lynx]

have you tried holding the throttle open a little to see if you can regulate the tickover if you can then as said above bend the tab on top of the carb if you can't then I would give the carb a good clean just in case there's some shit left over from the manufacture process also check the choke closes if that doesn't do the trick check the timing

[Hammer]

Cheers guys and thanks for the prompt responses. Yes the timing is ok and the choke closes fine. I will try to regulate the tick over from the throttle but I've got a feeling that this isnt going to work. The main jet is 124, it came with a 118 but i was advised to change it to 124. Anyone know if this seems right?

[missing lynx]

the main jet wouldn't affect tick over what have you got the air screw set at ? it should be aprox one and a half turns out as a starting point. Have you asked the supplier of your kit for jetting recommendations ?

[Tony Hart]

I originally had a Scootopia 22mm on a Casa kit and had the same problem. There was a blockage from production in the idle circuit that couldn’t be shifted with air or carb cleaner. Returned it for a replacement. Have heard since from a different dealer that they have had the same issue on a couple of these carbs.

Tony

[Toddy]

Is there any slack in your throttle cable ?

[Hammer]

I dont think so Toddy, but would this make any difference anyway? Following Tony's reply I am increasingly beginning to think that there is a fault with the carb in the idle circuit.

[grandpa]

Hi hammer
The slides for the jetex and copies are different for 150 and 200cc.The 200 uses a flat slide and the 150 uses a scooped out slide.I believe the Scootopia carbs come with both types of slides. looking at the pictures of slides on Scooter Restorations the 150 seems to have a bigger cut out at the bottom of the slide than the 200 so might be worth trying a 150 slide if you haven't yet.One assumes you have cleaned the jets particularly the pilot jet
Good luck
Grandpa

[rossclark]

the main jet wouldn't affect tick over what have you got the air screw set at ? it should be aprox one and a half turns out as a starting point. Have you asked the supplier of your kit for jetting recommendations ?

I had a similar issue with my Lince 200 when I put an SH2/22 on it - it would not start with a 124 in - I believe that the fuel for the pilot has to flow through the main jet to get to the pilot circuit so it does have an impact on low running too.

Mine would do nothing with p45 /m124, I changed to p50 / m124 and it would pop a couple of times with the airhose on and start but very boggy with it off. Dropped the main back to 118 and it starts and revs clean with the airhose on.

[Hammer]

Interesting because my pilot is 50 main 124 at the moment. When you had this configuration did you also have tick over problems or just lumpy running?

[rossclark]

It wouldn't start properly with the air hose on - it would fire few revolutions then bog out.

With the hose off it would start but was really lumpy wouldn't rev out and wouldn't tick over.

It would be worth taking your airhose off to see if that makes much of a difference.