Skidmarks Posted June 22, 2020 Report Share Posted June 22, 2020 Hi guys, New to trials, so forgive my ignorance, just after a few pointers please. I’ve just got a Sherco ST250 2016, Running it at 75-1 and riding in Surrey U.K. I believe the bike is standard.....unmolested.....! Bike starts easy, first or second kick hot or cold, when I remember to put the lanyard thing back on. Runs and rides great except it has a hanging idle ( think that’s what its called) when it’s hot, also when riding downhill using engine braking bike wont settle back to a nice idle. A fellow rider suggested the pilot jet needed cleaning, another suggestion was the fan was faulty, causing it to overheat. So carb off, and cleaned inside and out. Fan checked, all good. Haven’t checked coolant yet. So can anyone give me some baseline settings for the carb. ie pilot, main, needle, clip position, Airscrew. Etc and any ideas how to clean up my idle. Thanks in advance. Quote Link to comment Share on other sites More sharing options...
carl ekblom Posted June 22, 2020 Report Share Posted June 22, 2020 I suggest partly blocked idle system or an air leak. Idle air/Idle mixture screw and idle stop screw must be correctly adjusted. Also check throttle cable and throttle. They must be well lubricated and move freely. A good reseller should be able to give you information about correct jetting. Make notes about your jetting and changes you do. I know, if everything is correct, advancing the ignition a few degrees sometimes can help a little to reset the idle quicker. About going downhill, I think full clutch, apply foot and hand brake to slow or retard Carl 1 Quote Link to comment Share on other sites More sharing options...
Skidmarks Posted June 23, 2020 Author Report Share Posted June 23, 2020 Carl thanks for the advice. So, carb off, thorough clean, throttle cable cleaned and lubed. All back together, nipped up carb rubbers a bit more than normal. Set airscrew to 1 1/4 turns out adjusted idle screw. Sounds better. will try uploading a video. Mike Quote Link to comment Share on other sites More sharing options...
thesolidman1 Posted June 24, 2020 Report Share Posted June 24, 2020 You might be lean on pilot circuit. On mine, I ended up going up two sizes to a 50, and (usually) my air screw is still only 1 turn out. Quote Link to comment Share on other sites More sharing options...
Skidmarks Posted June 25, 2020 Author Report Share Posted June 25, 2020 In the manual I’ve got it states that the pilot jet is 33, and the main 122. As far as I know that’s what’s in there. This is for U.K. Riding. Will check next time I’ve got the carb off, but as it’s running better now....... It would be good to know what other riders are using. If my pilot is a 33.....And I say if....then 50 does sound high, but if it works for you.? Anybody know how to upload a video, tried but it says my files too big.? Quote Link to comment Share on other sites More sharing options...
b40rt Posted June 25, 2020 Report Share Posted June 25, 2020 "If my pilot is a 33.....And I say if....then 50 does sound high, but if it works for you.?" Depends what elevation they are at. Quote Link to comment Share on other sites More sharing options...
Skidmarks Posted June 25, 2020 Author Report Share Posted June 25, 2020 Just been on to my local dealer, I’ve been told that it should be 125 main, 45 pilot, needle second from top. Need to pull mine apart again and get the magnifying glass out.... hate getting old. Quote Link to comment Share on other sites More sharing options...
Skidmarks Posted June 25, 2020 Author Report Share Posted June 25, 2020 Quote Link to comment Share on other sites More sharing options...
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