What's on your bench today?

[High Scale]

Thanks, I've only modded the exhaust port on one 020t, exhaust modding is the normal thing for my saws, I will have to try the port route again.

[spudulike]

Thanks, I've only modded the exhaust port on one 020t, exhaust modding is the normal thing for my saws, I will have to try the port route again.

 

If you do then understand what the constraints are - it isn't just taking a dremmel to an expensive cylinder and crossing your fingers:blushing:

[GardenKit]

Customer brought his Mountfield in for service and "sharpen". Said it was working well but probably needs a sharpen by now. He does not use it much apparently!

 

Now, the dilema, should I sharpen it or fit the new one? Mmmm...

[TGB]

He might not be using it much... but is he using it to cut grass or spread stone chippings on the drive?

[Eddy_t]

Customer brought his Mountfield in for service and "sharpen". Said it was working well but probably needs a sharpen by now. He does not use it much apparently!

 

Now, the dilema, should I sharpen it or fit the new one? Mmmm...

[ATTACH]127063[/ATTACH]

 

New one would be the best idea, that blade is FUBAR

 

 

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[wisecobandit]

It appears, as you suspect, that the fuel is not getting up to the carb quick enough.

 

I dont think it will be the needle height as it runs well once started. More likely to be loss of impulse, This could be from a poor seal between the carb and manifold, a damaged or stretched pump diaphragm, or a poor seal of the pump gasket. ( the little raised lines on the pump cover create the seal against the gasket, and the sometimes erode away.)

 

The fuel pick up hose could be porous, but that would most likely effect the running too.

 

Including replys to Mr.Spudders and Rich to lol.

 

Spud the chokes definetly working as it should. It has a new 180 carb on it about 12 mths ago so is adjustable with l and h screws.

 

Fuel line was replaced about 6 months ago with an oe part along with filter when I did a quicky service xmas time so not thinking its likely to be that.

 

So process of eliminatation appears to be possible inlet manifold replacement, hence mentioning plug colour is good it could still have a bit of an air leak around the impulse part of it somehow? Its still the original and I know its a 2006 saw. (know in my possession to fiddle with)

IS it worth replacing tank vent at the same time as Rich mentioned? Doesn't ever seem to be gassy when you take the cap off?

 

Just wandered about needle height that if the needle wasn't sealing it may allow fuel to run back down into the tank somehow but it runs fine once its started in all fairness.

[Rich2484]

The tank vent can be tested by pressure testing the tank. Before the pressure tester came along I used to blow back down the fuel pipe with the cap on and see if it built up pressure, also sucked on it with tank empty to ensure the vent was letting air in. But I guess that's probably a bad idea nowadays.

[spudulike]

When talking about needle height, you are normally talking about slide type carbs, the needle valves in this carb should seal and stop fuel flowing in to the carb when the metering section of the carb has enough fuel in it to run the engine.

 

It could be a leaking needle valve, this can cause starting issues as can the metering arm height which should be level with the part of the carb body the diaphragm sits on.

 

I guess the thing to do is when the saw is cold, pull the saw over 15 times with the choke on and the plug should be pretty wet - so wet that when the plug is held by the end and flicked at a flat surface - it should send a few drips of fuel out.

 

Has the compression been checked yet? The tank breather may be the problem as Rich says - it is a small green rubber affair to the top of the tank above the filler cap but hidden by the plastic cover.

 

Try starting the saw after the filler cap has been undone and then re tightened - if it helps....bingo:thumbup:

 

These saws are often seized by weekend warriors who haven't come across two stroke oil before:001_rolleyes:

[GardenKit]

As a matter of interest, was the new 180 carb a Zama, or a cheap copy part?

If Zama you should be able to discount the carb, but if not????

[spudulike]

As a matter of interest, was the new 180 carb a Zama, or a cheap copy part?

If Zama you should be able to discount the carb, but if not????

 

I know exactly what you mean...Wolfmans Stihl 023 comes to my mind:001_rolleyes: