June 28, 201313 yr hi just got my self a lovely 155 bultaco sherp 350t bike runs a treat although I feel tick over could be bit higher I can only see one screw cant see any on right side due to exhaust there seems to be one on other side but manual shows two is the one I got just got air screw or is this a idle screw don't want to mess until I know many thanks
June 28, 201313 yr hi mate there should be 2 screws on the L/H side 1 is bigger than the over the bigger 1 is your idel screw the air screw is on an angal thats why you probely cant see it if you look close you will see it if the bike is runing good as you say dont touch the air screw. if the bike dosant cut out the way it is i would just leave it. but if it bothers you just run the bike untill its warm then turn the big screw clock wise only a littel to you hear the bike ticking over abit faster hope this helps.
June 28, 201313 yr Author cheers mate ill have a good look tomorrow saw angled piece but it looked blank perhaps got dirt in it any way ill leave that one it ticks over with no throttle but after about 30 seconds will stall so it needs just a bit thanks for help
June 28, 201313 yr Author mate just checked manual its saying angled one throttle stop screw ? straight one pilot jet screw ?
June 28, 201313 yr The one on the angle is the throttle stop screw because the throttle slide rests on it, so when you screw it in it lifts the slide. This lets air in and increases the engine revs by drawing through fuel with the air. Screw it out and the slide will eventually close shut - no air, no fuel, no tickover. The other screw is the mixture screw (air screw as it controls the amount of air passing through it) which will also increase and decrease revs as it richens or weakens the mixture through the pilot system which controls slow running. Screwing it out lets more air in which weakens the mixture. In shuts the air supply off letting more fuel through which richens the mixture. Set the mixture screw to 1 1/2 turns out from fully screwed in. Then turn the stop screw in or out to get a slow tickover. While it is ticking over again adjust the mixture screw by turning it very slowly either in or out about 1/8th to 1/4 of a turn. Listen to the engine as it will either run faster of start to stall. Turn it in the direction that causes it to run faster and keep turning until it starts to run slower again. Turn it back to the point at which it runs fastest. Then turn the stop screw out to reduce the tickover to the level you want. Leave it for a while to see if keeps running. If it falters and dies start it up again and while ticking over repeat the above process. If the carb is in good condition and the engine is in good fettle, particularly the crank seals, you should now have a smooth tick over You should find a tuning guide here http://amalcarb.co.uk/downloads/
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