Stihl 025 oil pump help

[landrover 101]

Hi - I have looked through all of D'Animals posts that i can find on here relating to oil pump repair on Stihl 025 but cant seem to find how to actually remove the oil pump from the case.
I have blown through all oilways, pick up pipe, plastic elbow, checked plastic drive and wire and still have no oil to the bar so the only thing left is the pump but i cant work out how to remove it.

Help Please

Thanks in anticipation - Dave

 

[D'Animal]

Is the oiler drive gear in good shape?


Can you turn the driven gear?

 

[landrover 101]

the drive gear looks ok and the top of the pump turns

 

[D'Animal]

Does the wire clip on the oiler drive gear spin easy?

 

[landrover 101]

the wire clip is tight on the plastic gear so when you wind it around with your finger end the plastic gear rotates ok on the crankshaft and the oil pump driven gear turns, the wire is not broken at the end and engages with the outer drum of the clutch, but still no oil !

 

[D'Animal]

You have checked that you do not have a hole in the pickup hose and that the filter is clear?

The white or black elbow is clear of debris? It is the elbow you removed to get to the oil pick up hose. Is the O ring on the elbow in good shape?

If you want to remove the pump you first have to measure the depth it is seated in the hole.

Take a 5mmx8mm screw and screw it in to the end of the pump. Pull/Pry the pump out towards the bottom of the saw. Make sure you do not put the screw in too deep or tight. You will crush the welch plug in the bottom of the pump.

When you re-install the pump, it has to set at the same depth.

 

[landrover 101]

Many thanks for your help - i will go through everything else again before i get to removing the pump - the only thing i have not done is actually remove the oil pick up pipe - i just blew it through in reverse to make sure it was clear so i will take this out and check it, if still no joy then i will pull the pump out and replace it as there does not seem to be anything else left to try.

Thanks again
Dave

 

[D'Animal]

If the O ring is cut or worn, it will allow an air leak adn not allow the oil pump to prime itself.

 

[landrover 101]

Thanks for that i will get a new O ring tomorrow and try that first as it will be a fairly quick and easy job before i tear it apart again to get the pump out

 

[D'Animal]

The size of the Oring is 6.1mm x 1.6mm

 

[Anand]

D'Animal , my hats off to you for helping many of us amatuers in the repair of chainsaws.

I am working on a 025 stihl. With the help of all your very illustrative pictures I have torn down the machine to where I see the pump drive gear. The gear turns freely when I turn it by hand. Do you suggest I still remove the pump as you say above and check it. The worm gear is bad, so I have to replace that. And the o-ring on the plastic is old and the end of the oil tube is also not in good shape, so I plan to replace all of these.

Please tell me if I need to remove the pump with the 5mmx 8mm bolt. If so, do you have any pictures on how to check the depth and other tips on how to remove the pump and what to look for ?

Next question is on this machine when I removed the clutch but the cover washer (part number 1121 162 1001) is missing. Maybe some one who worked on this before left it off? Please can you confirm that this part goes on before the clutch. And if it does, will there be room for the worm gear to be installed ?

Many Many thanks for all your help.

 

[D'Animal]

You do not have to remove the pump unless it is locked up.

 

[Anand]

Thank you very much.

Any comments about the cover washer question I asked. Thanks a lot for your help.

 

[D'Animal]

The began using the washer in the year 2000 production. No serial number break since it covers the 021, 023 and 025 chain saws. The only way to tell if you should have one is to measure the width of the clutch carrier or clutch spider. It is the center piece of the clutch.

The Old style clutch spider that does not require the washer is 13.5mm wide

The New style clutch spider that does require the washer is 12.7mm wide

 

[Anand]

Wow! there is no way i would have known that. Thank you.

In your earlier post you mention that only to work on the pump if its locked up. The fact that the drive gear spins freely, does it mean that the pump is not locked up ?

And when I rotate the drive gear should I see that in the pump move correspondingly, while looking at it at from the bottom of the chain saw ?

Also is it okay to clean the plastic housing where the clutch was, with a water based solvent ? there is a lot of saw dust. But I am worried if any of this solvent will make it past into the crankcase around the crank shaft. Any suggestions or ideas. I will try to get a digital pic to make it more clear.

Sorry if i am dredging up old information again.

 

[D'Animal]

You can clean it with Brake Clean if you want. You are not going to hurt anything in there.

 

[Anand]

Thank you again.

Please look at my 2 questions about the pump in the above post. Much appreciate to get your thoughts on those.

 

[D'Animal]

You should be able to reach in with a screw driver and rotate the gear on the pump and it should turn easy.

 

[Anand]

Thanks for all your Help. Yes the gear rotates when I turn it by hand.

I measure the spider on the clutch as you mentioned and it measures 13.5 mm. So I went ahead and assembled the clutch as I had found it. But, I see that when I put the sprocket back on there is a gap, that is the sprocket can move back and forth a bit. Looks like there is a 1/8th inch gap. Is this normal ? Hopefully the bar-chain will keep the sprocket pressed and held onto the clutch right ?

Please let me know ur thoughts on this.

 

[D'Animal]

The 1/8" gap between the sprocket and washer is normal.

The gap will close as you use the saw and the clutch drum heats up.