MS250 - What have I done??

[IRONJACK]

Update:

Fitted the new fuel pipe this arvo, (very fiddley) now running sweet as nut, very happy. Thanks again spud!

I've set the carb screws to 1 full turn out each. Seems fine to an untrained ear, little puff of white smoke on reaching full revs, is this ok? Any basic tuning tips?

[spudulike]

Set the L screw first - start on 1 1/4 turn out, wind it in - the saw will race and then start to die, wind it out past the bit where it races and leave it on the bit just past the fastest revs - about 1/4 turn and then adjust idle.

 

Give the H screw 1 1/2 turns out, rev it flat out - it should sound very rich and thumpy on the top end and smoke, wind in the screw just to the part it clears and sounds ALMOST clean at high revs. It should sound "Burbly" on the top end - known af four stroking - this is where you need to be and takes some experience to do it well.

 

Do not tune for maximum revs or think the saw reving higher is better - you are probably leaning out the fuel too much and it will seize in time.

 

A safer method is to use a Tach rev counter and set it 500RPM under the max manufacturers spec - this is a specialised bit of kit.

 

It all takes time to learn and experience - make sure the air filter is clean and the tank is full when you do this and make sure the saw is warm.

[IRONJACK]

Great, valuable advice. Many thanks again spud.

I feel like I owe you at least a beer, where are you based?

[spudulike]

North Herts - Near Baldock, think many people owe me a beer:001_smile:

[Acle Garden Machinery]

Strip the carb completely and clean all needle valves. Replace the dia and gaskets and replace fuel this will solve the prob

[IRONJACK]

Strip the carb completely and clean all needle valves. Replace the dia and gaskets and replace fuel this will solve the prob

 

Thanks for your input Acle. Did you actually read anymore than the first post in this thread?