Husqvarna 51 wont stay idleing

start by checking all ur fuel lines for holes then proceed to clean or rebuild ur carb the ethonal in fuel is cloging small engine carb jets and making needles stick so then adjust ur carb back to factory settings try with new air filter as well and run 89octane or higher in your two stroke motors u will c a great differance in performance

Remove cover on the wheel, tighten the ball bearing idler. Should be 3 thumb screws to remove cover.

Carb adjustmwnt requires a special tool and a tacho, the saw is set from the factory for the best emmisions, however it may need a small adjustment, this should be done by a qualified dealer, incorrect adjustments can damage the engine.

The carburator may need adjusting. If this doesn't correct the problem check the air filter then clean or replace it. If this doesn't correct the problem inspect the diaphragm for holes or if it has become hard. If so replace it. Otherwise the carburator may require rebuilding or replacing.

Most chainsaws and small engines are 1.5 turns out.

You need to set the mixtures for the carburetor. You will find a Low and High adjustment screw. At idle turn the screw in or clockwise until the rps starts to decrease. Then start turning it out till you hit max idle rpms. Turn screw back in a quarter to half turn and it should be idling smoothly. Be careful here and get someone to hold saw if necessary but hold in throttle to full speed and do the same with high adjustment screw. turn it in till rpm starts to drop then back it out until you get to max rpm and it won't go any higher then turn it back in a half a turn.

Find the 2 screws. There will be a (h) high and (L) low. These are for hig rpms and low rpms. First tighten the screws. Then unscrew them about 1-1/4 turns. Then start the saw and let it warm up. Start with the high rpms first pull the trigger all the way then adjust the screw in 1/8 turns either way until it is running good at high rpms. Then work on the L rpms. Get the saw to idle then pull the trigger, there should not be any hesitation when going from L to H rpms. Just adjust the low same as the High. They have to work together so if the high is good and the low is not just right turn the h a small amount. If you have any more questions let me know

Probably need to re-adjust the carburetor jets. They are very small screws in the base of the carburetor. They will be labeled with an "H" and an "L" . Set the low speed first by turning it in slowly until the rpm drops slightly then start turning it outward untill the engine idles smoothly. At that point you can also adjust idle speed. Then you need to be careful here but you need to hold the throttle wide open at the same time adjusting the high speed jet. Turn it in until the rpm drops then slowly turn it out. The rpm will keep increasing. Once you get to a point where it is max'ed out then screw the jet back in one half a turn. Changes in altitude like using your chainsaw in town versus going to the mountains for firewood can sometimes make it necessary to adjust the fuel/air ratio.

Hi First turn them(H and L) clock wise until the end and then adjust.

high speed H=3/4 turn

lowspeed L=1 1/4 turn

idle speed T adjust accordingly

best regards savumihai71

You'll have to release the brake with the cover off the saw. You just need to find a way to brace it well enough.
If you really can't do this, then it suggests your chainbrake is faulty, of ath the very least not adjusted right.

The carb needs to be adjusted. Look for 2 adjustments label High(H) and Low(L). Low is the one that you want. Start you chainsaw and let it warm up and turn the L adjustment a until you are able to let it idle on its own. Hope this helps.