Stihl MS261 - insulation mat (missing part nr)

[singinwoodwackr]

Are you stockpiling these for any particular reason? Looks like you could setup a production line!

I bought a truckload of old parts, carcasses, etc. 1122, 1128, 1125, 1118, 1119, and some misc, these are 1122s.

I'll be cleaning parts for months, lol.

 

[MartDalb]

When you get that one done...wanna do a few more? View attachment 1192880

holy h, that's alot of pumps!

 

[MartDalb]

Put up a photo of the pump. If it is metal you might be able to disassemble it and clean it up.

See the control bolt (adjustment screw) shaft. About halfway down is a black about 1mm diameter roll pin. Push out the roll pin using a suitable pin in a drill press or similar.

Once the pin is out the control bolt can be pulled straight out. That should allow the pump piston to move towards the brass end plug and will free up a straight through path to the in and out of the pump. The control bolt may have one or two "O" rings on it to seal the shaft. Once the "O" rings are removed there is nothing but metal left.

Control bolt removal and piston shift may allow enough access for solvents to clean everything. If not your next step is to figure out if you can remove the brass plug on the left side. Older pumps had a plastic plug. Newer ones have apparently moved to the brass plug to discourage disassembly and repair. I don't know how tight it is in there. At this point you don't have a lot to loose.

Let us know how you make out.

So, taking it apart was easy, it also became a lot more easy to spin around, after moving the parts around.

I put it back in some Oregon mx14 - and I will try to clean it up real good tommorow.

This might actually work, if I can manage to put the pin back into place, and the pump hasn't taken some weird damage to it, so it doesn't work....

Awesome stuff!

Thanks!!

 

[singinwoodwackr]

This might actually work, if I can manage to put the pin back into place, and the pump hasn't taken some weird damage to it, so it doesn't work....

Awesome stuff!

Thanks!!

pair of pliers, taped so they don't mar the pump.

 

[pioneerguy600]

Drill a hole through a set of needle nose pliers just undersize of the hose, it works wonders getting the new hose on and even is helpful getting the old one off the pump but most often I carefully cut the old hose off the ribbed nipple as the old hose has conformed/shrank to the ribbing and no way will it pull off.

 

[SteveSr]

So, taking it apart was easy, it also became a lot more easy to spin around, after moving the parts around.

I put it back in some Oregon mx14 - and I will try to clean it up real good tommorow.

This might actually work, if I can manage to put the pin back into place, and the pump hasn't taken some weird damage to it, so it doesn't work....

Awesome stuff!

Thanks!!

It would probably be a good idea to shoot some carb or brake cleaner through the pump with the piston backed out to make sure that the pump chamber is cleaned. This is where any crud (chips, sawdust, etc) that make it through the pickup screen can get lodged and cause excess leakage and reduced oil flow.

The only trick is to hold the piston to the right (in your photo) when putting the control bolt back in. After that nothing moves and just press the roll pin back in with the same press that removed it.

BTW, did you remove the brass end plug? If so, how did you get it out and how tight was it?

Heep in mind that these pumps have NO internal seals. The only thing that keeps them from leaking (much) are the machining tolerances between the pump piston and the piston bore. Therefore cleaning with acids, bases or any cleaners that would attack either one is not advised. Maybe @Mad Professor can provide some guidance on what will breakdown/clean polymerized vegetable oil.

I am thinking that an ultrasonic cleaner might be good here as these work good on hard surfaces like metal by causing cavitation on the surface to break up the dirt/grime/oil.

 

[MartDalb]

The operation was a success, but the patient died.


So, putting it back together worked fine, but...

Even having it cleaned out, as much as possible, it simply won't roll over as it should.
It honestly feels like it could be damaged, bent or something similar.
The pump is clean now for sure.

I did not get off the brass end plug, that would not budge.

This has been a great learning experience, no matter the end result.

I will surely meet this issue again.
This one, I think, has internal damage or similar where something is bent ever so slightly.
As I mentioned the wormgear was damaged as well, it does take quite some force to break those, i'd think.

Thanks to all who showed up here and helped out!

 

[HansFranz]

Hardened canola will test your patience, sets up like the hardest kind of glue and little if anything dissolves it quickly.

I suspect oven cleaner (lye, sodium hydroxide) will cut it...although it'll also eat the aluminum...

 

[chilipeppermaniac]

When you get that one done...wanna do a few more? View attachment 1192880

Holy Smokes, why so many? That many abusers, part easily gunks up, bad design?

 

[MartDalb]

Holy Smokes, why so many? That many abusers, part easily gunks up, bad design?

I have seen many Stihl saws on my workbench, and only a handful of bad oilers.
Mostly the cheaper ones from ms170/180 and similar.

People run crap chain oil, bio oil (because they are told to use bio from the seller in many cases).

In this case, I litterally had to flush the oil tank with fuel and MX14 to get gunk etc out, even small bits of metal and a spring came out of that tank.

In most cases, i'd say its a case of "user error".

 

[chilipeppermaniac]

I have seen many Stihl saws on my workbench, and only a handful of bad oilers.
Mostly the cheaper ones from ms170/180 and similar.

People run crap chain oil, bio oil (because they are told to use bio from the seller in many cases).

In this case, I litterally had to flush the oil tank with fuel and MX14 to get gunk etc out, even small bits of metal and spring came out of that tank.

In most cases, i'd say its a case of "user error".

Gotcha, MartDalb,

I have only used Bar oil in all my saws since 1994.

 

[SteveSr]

The operation was a success, but the patient died.


So, putting it back together worked fine, but...

Even having it cleaned out, as much as possible, it simply won't roll over as it should.
It honestly feels like it could be damaged, bent or something similar.
The pump is clean now for sure.

I did not get off the brass end plug, that would not budge.

This has been a great learning experience, no matter the end result.

I will surely meet this issue again.
This one, I think, has internal damage or similar where something is bent ever so slightly.
As I mentioned the wormgear was damaged as well, it does take quite some force to break those, i'd think.

Thanks to all who showed up here and helped out!

Before you throw in the towel... try putting some bar oil in it for lube to see if it turns any better.

After you have thrown in the towel... try some heat and a pair of sharp vice-grips to remove the brass plug. At least you can see what was in the pump!

 

[singinwoodwackr]

Worst case...the pumps aren't that pricey

 

[StihlsawuserMS361]

Agree, for the labor involved, then always wondering "what if", or when /will it reoccur.

Had similar issue with my 360. New pump, as I didn't want to keep removing the clutch. New and done

 

[MartDalb]

Before you throw in the towel... try putting some bar oil in it for lube to see if it turns any better.

After you have thrown in the towel... try some heat and a pair of sharp vice-grips to remove the brass plug. At least you can see what was in the pump!

If nothing else, Id like to see the inside of a pump like this, and perhaps see what causes it to be defective.

Thanks again!
Much appriciated!

 

[MartDalb]

Worst case...the pumps aren't that pricey

I agree, but here in EU prices are a lot higher than in the US.

And for a used saw, this will cost me 1/2 of what I paid for the saw initially.
Seller was nice at first, but seems to have forgotten his promise to pay up, if it had any defect parts.....

 

[2StrokeFondler]

I agree, but here in EU prices are a lot higher than in the US.

And for a used saw, this will cost me 1/2 of what I paid for the saw initially.
Seller was nice at first, but seems to have forgotten his promise to pay up, if it had any defect parts.....

Where are you buying? New oil pump #1141 640 3200 is 55,5€, that's not too bad...

 

[MartDalb]

Where are you buying? New oil pump #1141 640 3200 is 55,5€, that's not too bad...

I have access to Stihl prices directly on site. So it is stihls listing price.

In Denmark its 66 euros. (Highest taxed country in the world)

And I didn't even pay double that for the saw itself.

Sadly seller was not trustworthy, a rare case for me.

Shi... happens. Ill report back in once its been fixed. I will change a few other things while at it. The av mounts etc seem kinda bad as well.

 

[cookies]

Stihl oil pump bodies are aluminum, the pump piston is steel. The pump body wears out but still pumps oil. They end up leaking when worn out casting oil mist all over the case side, clutch, drum etc. I stopped repairing them, I only replace with new unless it is NLA because they end up dripping or dusting the case half with oil.

 

[MartDalb]

Stihl oil pump bodies are aluminum, the pump piston is steel. The pump body wears out but still pumps oil. They end up leaking when worn out casting oil mist all over the case side, clutch, drum etc. I stopped repairing them, I only replace with new unless it is NLA because they end up dripping or dusting the case half with oil.

yeah, I have just seen very few defective ones, especially like this one of mine.

I never, ever had luck with non oem oilers. They are pure trash.