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Cannot use choke even when cold
Posted: Fri May 12, 2023 6:12 am
Author: kev edwards
I have refurbed 28mm pumpers, plungers done bt Z1015, jetting is stock , will fire up on choke but have to turn off immediately, if I keep it lifted it stops the motor, once warmed idles and runs perfectly with light tan plugs, seems it does not like choke even if I only have it partially on, stumped by this.
Re: Cannot use choke even when cold
Posted: Fri May 12, 2023 7:22 am
Author: zed1015
Pilot mixture is too rich.
Lean it off on the air screw and if that isn't enough then fit next size smaller pilot jets.
Getting it off choke asap is a good thing but an over rich pilot will cause lumpy running and plug fouling at low revs and when in traffic so watch for that as an indicator.
Re: Cannot use choke even when cold
Posted: Sun May 14, 2023 4:57 pm
Author: kev edwards
Took the carbs back off after trying with air scews 2 and 1/2 turns out, did not realise I had weakened it off that much, still sooting up, for some reason I had put 17.5 pilots in, probably because I had the same size in the 26 pumpers I had on, so back to 15 pilots, air screw 1 and 3/8th's out fired straight up, choke off immediately and off for a 20 miler, pulls like a train, got back idled for a couple of minutes , plugs out tan colour with a touch of soot on the plug threaded part, I haven't even put the vac gauges on these yet, and am very pleased as they are at the moment.