Starting after top-end rebuild and new carb

[HxPaul]

I have a Casa 185 running on a scootopia sh2/22.I'm using a 130 main jet and a 48 pilot jet.Scooter starts first or second kick everytime and runs as weet as a nut.

[HxPaul]

My scootopia carb used to stop or stutter for no reason.I found reference marks inside the float chamber where the float had been catching,so I bought an original dellorto float and found that it was fractionally smaller than the original float.I fitted the dellorto float and the problem went away.

[loadedscooterist]

Hi Paul, Thanks for the thoughts. Not sure the float is going to make masses of difference to me as I think its something else. In that I am thinking of electrics - for example not sure how I can measure spark strength - I do have a spark but not sure how strong it is. The other thought I have is the timing. I am pretty certain its sitting at 21 degrees as thats how I set it up but before I go pulling flywheels off I want to see if its carb related.

[mick1]

piston wrong way round could be an option......

maybe worth a leak test as well....

[Daggs]

Nick is referring to a different type of carb that uses an adjustable needle, you can ignore that.
You don't say how you use the choke when starting?
Sometimes it's just a matter of throttle position when kicking over.
Usually keeping the throttle closed is the advice and for one of my scooters that is so.
However, another one I own needs throttle from cold. So basically every scooter has it's own quirks.
Some scooters need the choke to remain on for some time. Others need it shut off soon after starting. Again, I have both of those experiences.
Carefully experiment with your starting technique.
Your jetting looks about right. (The Atomiser will be 4899-1)

[loadedscooterist]

Thanks for clearing that one up. I have only ever used Dell orto so my knowledge of others isn't great (apologies)

OK so choke is working and adjusted so its open 3/4 way round and also no more than a 1/4 of throttle when kicking over. Maybe I do have a poor starting technique?!? - one thing for sure my right leg is getting a lot of exercise! maybe I will work on that too!

[HxPaul]

Your jetting looks about right. (The Atomiser will be 4899-1)


The atomiser should be 5899-2

[loadedscooterist]

So with the 22mm scootopia carb you get two slides. One for a 200cc with a 5899-2 atomiser. You also get one for 150cc with a 5899-4 atomiser. My thought at this point is how much difference is there between the two slides in terms of what they do in the start-up process?

[nick b]

sorry I didn't mean to confuse you the point I was trying to make about jetting we always seem to go big then work back but I have found it easier to set going smaller upwards the atomiser slide pilot are reasonably easy I have found the main jet+ mixturescrew the ones to get right

[HxPaul]

The 150 slide has a cutaway portion at the back of the slide,the one for 200 doesn't.I've used the 200 slide in my Casa 185.