MS039 Bogging down/lack of power need some advice?

[JSFGreig]

Hi all

 

I recently bought myself an 039 which was running very well untill a few days ago

 

I was cross cutting some walnut which was coming along nicely untill the saw started to struggle/bog down/lose power

 

Ive checked all the obvious things:

 

chain is sharp

right length bar and chain

compression

fuel mix

airfilter

carb

 

the saw idles fine and revs up nicely but struggles to cut(chain is definitely sharp honest!)

 

its recently had a new clutch drum.

 

maybe its time for a new clutch?

 

any second opinions would be greatly appreciated

[spudulike]

Firstly, forget the clutch. If it was slipping, the saw would rev up and the chain would move slower than it should for the high revs - there, that has saved you £30:thumbup:

 

IMO, bogging of the saw or the inabillity to hit high revs and to keep the saw going in the cut is down to the carb or fuel system.

 

Assuming that you have 150psi or more or that you have popped off the muffler to check for scoring of the piston, the problem could be one of the following: -

 

Blocked fuel tank vent - this would cause the saw to die or struggle for decent power - not sure where it is on this saw - you can eliminate this by running the saw with the fuel cap loose and see if it overcomes the fault.

 

Fuel filter Check it is clean and that your fuel pipe is in good condition

 

Air leak Check the carb is on tightly and the boot isn't holed, make sure the carb boot is mounted tightly

 

Carb H&L setting - if the saw doesn't rev cleanly from idle then the L setting needs riching, if the saw is revving like a banshee but has no power then the H setting needs riching.

 

Dirt in the carb there is a small filter in the pumping top section of most carbs, typically if there is dirt on this filter, it will cause bogging and poor running.

 

Plug Take a look at the plug, it is possible that it has a problem but IMO, most guys change plugs in despearation, they are rarely the problem.

 

There you go - you did ask:thumbup1:

Spud

[kev_s]

From my basic knowledge it does sound like fuel, but because it was cutting fine on same fuel before maybe some issue with delivery of fuel into cylinder.

 

Kev

[lendahand]

There you go - you did ask:thumbup1:

Spud

 

Excellent, one easy thing you missed, check the muffler is not blocked at outlet or inlet. Common problem.

[JSFGreig]

cheers for the advice guys next time i get her out ill have a good check for all the above

i dont think my neighbours will appreciate me starting her up at this time of night

 

i will get back to you on any progress i make/dont make

 

thanks again

[lendahand]

Put some fresh fuel in with the correct mix/ratio to oil.

[spudulike]

Excellent, one easy thing you missed, check the muffler is not blocked at outlet or inlet. Common problem.

 

If it has a spark arrestor then worth a check or just remove it, they are of more use in dry conditions - can't say we get much of that!

Spud