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Saw will die with full throttle.


Hunter
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Oh sorry, the issue really must be elsewhere then and not with the carb! There are different levels of cleaning as we all know - has it been in a US cleaner??? Probably not. Has he set the metering arm correctly.....probably not.... have the H&L screws been out and cleaned......oh, you know the answer already:lol:

 

The issues are more often than not, with the carb. It just needs someone who knows what they are looking for to find the fault and resolve it.

Thanks a lot, I have to admit I am new to all of this, and still learning.

I did not use any US but just carb cleaning spray. I did not take any screws out because I am not confident yet.

Will give it another clean, and will order another carb service kit, may be more expensive than the one I used.

Thanks everybody for helping me out.

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Chances are that if you turn the H & L screw 1/4 turn out on each, the saw will work just fine. Just don't turn the H screw CLOCKWISE as it will lean the fuel off!

 

You may need the special carb adjusting screwdrivers as the heads are probably splined or D shape.

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Just reading this - I like to know how things work..

 

I might be wrong, but is this the basics of whats going on?

 

The throttle is linked to the air intake of the carb.. so pull the throttle, the air intake opens up more, and the air can get through quicker. This means there is less resistance for the cylinder so the cylinder can move quicker - engine goes faster.

 

As the air moves through the carb it passes the nozzles for the fuel (the H and L) and as the air goes past it picks up fuel and draws that into the cylinder. More air moving means it has to pick fuel quicker. If the H nozzle won't dispese enogh fuel quick enough then the cylinder has too much air / not enough fuel and it will die?

 

So (unless someone says that what I think is all wrong - which it might be), the problem is most likely to be the H side of the carb. A blocked nozzle or a screw that over time has screwed in blocking the fuel line so now not enoguh fuel can get past for full throttl. My first thought then would be to adjust the screw, open it uip a bit - there are youtube vidoes of this I am sure.

 

If the engine is tricky to start then its the L screw to adjust.

 

My next thought then would be if a new cab kit was fitted perhaps there was a leak in it somewhere letting air in instead of fuel?

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Thanks a lot, I have to admit I am new to all of this, and still learning.

I did not use any US but just carb cleaning spray. I did not take any screws out because I am not confident yet.

Will give it another clean, and will order another carb service kit, may be more expensive than the one I used.

Thanks everybody for helping me out.

 

Carb cleaning spray is a good start. But as others say you need to remove screws, spray through there too. You basically want to make sure the spray is coming of all the corresponding passageways and jets. The slow speed jets in the carb are typically the ones that get blocked (the ones around the butterfly throttle).

 

Regarding the screw positions - just record where the screws are to start with, then you can always put them back where you found them. To do this, get a good look at the screwhead or the screw driver. Turn the screw in (clockwise) until it stops, counting number and fraction of turns. Repeat for other screw. Now you can return them back to where they were after taking them out for cleaning and after having a play with carb tuning.

 

Take the time to learn to tune a carb, it's not difficult.

 

bmp01

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