stihl fs400 problem

[johnw_123]

hi.

i have a fs 400 that has developed a problem.

first started to bog down after about 5mins of use,

checked for spark before starting and after and all is good.

so cleaned the carb and now it will start fine and idle as it should but on wide open throttle it bogs down unless i turn the choke lever so it is just off the full choke postion and then it will run fine (idle and full revs)...also replaced the primer bulb and lines....any ideas

 

thanks john.

[Richard 1234]

Sounds like you need to adjust the carb screws. Too lean on top end

[stihlmadasever]

Check the gauze at the exhaust for excess carbon blocking it.

[harrythecat178]

Replace the carb pump diaphram and gasket, its probably stretched and not pumping properly

[johnw_123]

Sounds like you need to adjust the carb screws. Too lean on top end

 

no screws to adjust as there is only a idle screw

[johnw_123]

Check the gauze at the exhaust for excess carbon blocking it.

 

there is no gauze(i take it you mean spark arrestor)

[johnw_123]

Replace the carb pump diaphram and gasket, its probably stretched and not pumping properly

 

 

thats probably my next port of call...or just get a new carb off ebay at least the replacement carb will have low and high speed adjusters

[harrythecat178]

thats probably my next port of call...or just get a new carb off ebay at least the replacement carb will have low and high speed adjusters

In all fairness the chinese ones off Ebay at £11.99 work really well