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Lumpy tickover

PostPosted: Sun Mar 29, 2020 9:14 am
by Stand63
Hi folks
Running a new build Scootopia 186 with a 28phbh with a tea strainer filter and AF clubman. Runs fine, starts fine and plug colour fine. I’ve adjusted the mix screw in and out and settled on the best spot for pick up and returning to tickover but it still remains very lumpy. It’s fine at start up with the choke on. Any ideas most appreciated

Re: Lumpy tickover

PostPosted: Sun Mar 29, 2020 10:02 am
by MickYork
An auto advance/retard is an option, cleans up the lower rev's.

What's your timing set at and full carb' spec ?

Re: Lumpy tickover

PostPosted: Sun Mar 29, 2020 11:04 am
by Stand63
Will have a look. Timing is 17. Main is 122 but will check pilot.

Re: Lumpy tickover

PostPosted: Sun Mar 29, 2020 1:22 pm
by Stand63
Pilot jet is size 70

Re: Lumpy tickover

PostPosted: Sun Mar 29, 2020 1:38 pm
by MickYork
I've not had a Scootopia 186 but 70 seems overly large for a pilot, are you sure that's not your choke jet ?

Re: Lumpy tickover

PostPosted: Sun Mar 29, 2020 2:04 pm
by Stand63
Sorry Mick. Pilot is 55 and choke is 70

Re: Lumpy tickover

PostPosted: Sun Mar 29, 2020 2:08 pm
by MickYork
Seems about right. Have you tried without the filter ?

Re: Lumpy tickover

PostPosted: Sun Mar 29, 2020 2:24 pm
by Stand63
Yes mate, no difference.

Re: Lumpy tickover

PostPosted: Sun Mar 29, 2020 2:40 pm
by MickYork
The port timings on some barrels can sometimes be a factor and you may always struggle, the auto retard is a good option for little cost and fairly easy to set up.

Re: Lumpy tickover

PostPosted: Sun Mar 29, 2020 3:48 pm
by Stand63
Thanks Mick. I’ll have a look