Stihl MS361 too much oil on chain and clutch drum

[SteveSr]

Clutch came right off with rope in spark plug hole, and I have one more question please:
Took the oil pump off this weekend and checked the discharge O ring. No cracks etc. I can't see where the suction hose could create the over oiling problem as it appears to have a snug fit, so I'm going to change the pump and replace the discharge O ring. I have a new Stihl pump, p/n 11356470460, whereas the original one to the saw is p/n 11280461. I have a Stihl parts catalog, listing 11356403200. Do the numbers change often?
Local dealer minimal help. Anyone have any ideas?
Thanks again guys, I appreciate any help!

About the only way to get too much oil through one of these pumps is that if the tank gets pressurized by heat and the pump is full of sawdust/chips that hold the piston open. The pump can be cleaned by removing the roll pin that retains the control bolt. Rotate and pull the control bolt out slightly to allow the piston to retract. Now shoot some brake cleaner or WD-40 through the pump.

You may or may not see what was in the pump come out. The only real way to check this is to measure the pump stroke before and after cleaning. If the pump was clogged there should be considerably more stroke after cleaning.

 

[StihlsawuserMS361]

Thanks SteveSr
What started this all was me leaving a piece of tape over the oil exit channel while cleaning and forgetting to remove it when done. I've maintained this saw well, pretty careful when filling oil and gas. I looked at the screen inside the oil tank, clear. Replaced breather check valve. Ran saw lightly for about 1 tank of fuel, cleaned again and oil everywhere. Ran it with plastic guards off, you can watch the oil spray off the chain and saturate the drum and brake. I hope the piston is stuck due to over pressurizations.
Otherwise, saw is great and I hope to have the seal tomorrow.

 

[SteveSr]

Thanks SteveSr
What started this all was me leaving a piece of tape over the oil exit channel while cleaning and forgetting to remove it when done. I've maintained this saw well, pretty careful when filling oil and gas. I looked at the screen inside the oil tank, clear. Replaced breather check valve. Ran saw lightly for about 1 tank of fuel, cleaned again and oil everywhere. Ran it with plastic guards off, you can watch the oil spray off the chain and saturate the drum and brake. I hope the piston is stuck due to over pressurizations.
Otherwise, saw is great and I hope to have the seal tomorrow.

The vent is one way... IN. The tank can/will still pressurize due to temperature differences. The screen in the tank isn't really much of a "filter". Debris will usually get flushed through the pump but sometimes can get lodged in the pump where it will collect more and more debris until you have an issue. Usually this results in low oil flow and leakage while sitting due to tank pressurization with temperature changes.

While the pump is out you can rotate the piston and measure the horizontal travel and compare it to the specs for the pump (assuming the control bolt is set for max output). There is nothing to break in these pumps. I don't see how a piece of tape could have done anything other than possibly force oil out the pump shaft. However, this should have gone away once the tape was removed. After you put the pump and clutch back on run the saw without the B&C and check for oil flow out of the oil port. If no oil you have a blockage in the output somewhere.

 

[StihlsawuserMS361]

I've been scratching my head on this too. While port blocked, it still oiled the chain, although much less. I doubt the tank is heat pressurized as our ambient temp has been low, and I never hear a pressure release when refilling.
What got me going was after I used it that one tank, I set it down in the garage. Came back the next day and there was quite a bit of oil on the floor. (usually a drop or two is normal, and a tank of oil lasts about two fillings of gas with the oil adjuster at full open) So I cleaned it that next day, ran it with both chain guard and inner plastic clutch cover off. Oil sprayed around the bar and chain, and soaked the clutch drum / area.So something changed after the port was blocked

 

[stihltech]

A lot of times the number printed on the part is a casting number that is used for the company’s reference. If you are replacing it you can use the original or a pump from a MS460 to get a touch more oil or from a MS460R for a lot more oil.


Sent from my iPhone using Tapatalk Pro

Clutch came right off with rope in spark plug hole, and I have one more question please:
Took the oil pump off this weekend and checked the discharge O ring. No cracks etc. I can't see where the suction hose could create the over oiling problem as it appears to have a snug fit, so I'm going to change the pump and replace the discharge O ring. I have a new Stihl pump, p/n 11356470460, whereas the original one to the saw is p/n 11280461. I have a Stihl parts catalog, listing 11356403200. Do the numbers change often?
Local dealer minimal help. Anyone have any ideas?
Thanks again guys, I appreciate any help!

Time to get a cup of coffee and sit back.
Top much oil. When the bar is off or lightly used. So the pump IS operating. Leakage possibilities: pickup hose. Output oring. Oil tank vent. Oil pump body. Running saw without bar or with bar and not cutting wood..
Is the excess oil inside the clutch drum? I would the consider a new pump. Other spots are out far enough they usually do not will the clutch drum area.
Oil is meant to be used up on the bar with wood chips to absorb it, not just to run off.
Other than the pump body being cracked, I would adjust the pump to the minimum. Also remember, a lot of oil will stay trapped under the inner guide plate. I have spent many hours chasing oil leaks for just this reason. Saws are not necessarily oil tight. The aforementioned heat and expansion will cause oil to move through the pump.

 

[StihlsawuserMS361]

Maybe something stronger than coffee at this point?
Quick recap. I've had this saw for 16 years now, so I have a pretty good take when something is off.
After I removed the tape, cleaned (removed clutch drum and brake etc. in cleaning) , ran saw / cut wood lightly for one tank, sat it down and returned the next day. Quite the puddle on the floor. Usually has some oil, this was excessive. Took it apart again, cleaned everything, removed plastic clutch cover etc...Ran saw, oil coming out the chain slot. Put bar and chain on, (left off clutch and side cover off) After maybe 3 minutes light throttle, visible oil spray everywhere which I expected some with covers off. Inside and outside clutch drum / shoes and surrounding area soaked. Tried it with saw flow adjuster at minimum , same. ( BTW, usually before I cut any wood, I run the saw until I see a bit of oil sling off the bar tip)
I did replace the oil breather vent valve, even though the old one checked OK. The inlet hose fits decent, no visible damage on suction side. Outlet seal looks great. No visible cracks on seal or pump etc..
So I have a new Stihl pump, p/n 11356470460A,whereas the original pump p/n is 11286470461 . (I can't seem to trace this p/n anywhere, told it was a new take off a 362 and is the same for 361).Tomorrow I'm replacing the outlet seal and pump. I get this is a pretty basic setup, not rocket science by any means. Oil in, oil out. I'm hoping the tape back up did something to this pump. My labor is free, I'm probably $ 100 into this saw at this point, no big deal there.
Any thoughts?
Thanks, again.

 

[Woodslasher]

The 1128 prefix probably means you have an HD oil pump on the saw (which just means it can be turned up higher). If I’m right, your new pump won’t oil as well/much. As for the pumps themselves, short of the housing breaking there’s not much that can fail except an o-ring or two. I’d have knocked apart your pump and checked those before you bought a new one, personally. I would have also re-istalled the bar and chain and run it with those, if it didn’t puke excessive amounts of oil while you ran it in the wood I wouldn’t have messed with it. All saws will puke oil if you run them with no b/c, I’d only worry if your chain isn’t getting enough oil.

 

[Stihl-Pioneer]

The 1128 number on the pump body is probably a factory part number for the housing itself or a casting part number which the 361 and 460 both use the same housing with different pistons.


Sent from my iPhone using Tapatalk Pro

 

[stihltech]

Maybe something stronger than coffee at this point?
Quick recap. I've had this saw for 16 years now, so I have a pretty good take when something is off.
After I removed the tape, cleaned (removed clutch drum and brake etc. in cleaning) , ran saw / cut wood lightly for one tank, sat it down and returned the next day. Quite the puddle on the floor. Usually has some oil, this was excessive. Took it apart again, cleaned everything, removed plastic clutch cover etc...Ran saw, oil coming out the chain slot. Put bar and chain on, (left off clutch and side cover off) After maybe 3 minutes light throttle, visible oil spray everywhere which I expected some with covers off. Inside and outside clutch drum / shoes and surrounding area soaked. Tried it with saw flow adjuster at minimum , same. ( BTW, usually before I cut any wood, I run the saw until I see a bit of oil sling off the bar tip)
I did replace the oil breather vent valve, even though the old one checked OK. The inlet hose fits decent, no visible damage on suction side. Outlet seal looks great. No visible cracks on seal or pump etc..
So I have a new Stihl pump, p/n 11356470460A,whereas the original pump p/n is 11286470461 . (I can't seem to trace this p/n anywhere, told it was a new take off a 362 and is the same for 361).Tomorrow I'm replacing the outlet seal and pump. I get this is a pretty basic setup, not rocket science by any means. Oil in, oil out. I'm hoping the tape back up did something to this pump. My labor is free, I'm probably $ 100 into this saw at this point, no big deal there.
Any thoughts?
Thanks, again.

I didn't specify what was in the coffee.

 

[StihlsawuserMS361]

I didn't specify what was in the coffee.

Sorry for the delay in responding, snow storm took out power and internet for a few days. Catching up to the last few replies.
It was mentioned previously the 11286470461 pump that came with the saw (MS361) has a higher output than the 11356470460 that I purchased was listed as fitting MS360 thru MS361,MS362C, and MS400C . Both pumps have adjustable oilers from the bottom base, about 1/4 turn limitations.
I apologize if I'm beating this to death, and I don't want to keep taking this apart, would the 11356470460 oiling supply, in everyone's opinion, be sufficient?
I may drive out the roll pin out later and see if anything looks out of place. I'm not anti-Stihl dealer, but dealer has a sign out front parts help wanted constantly...

 

[StihlsawuserMS361]

Sorry for the delay in responding, snow storm took out power and internet for a few days. Catching up to the last few replies.
It was mentioned previously the 11286470461 pump that came with the saw (MS361) has a higher output than the 11356470460 that I purchased was listed as fitting MS360 thru MS361,MS362C, and MS400C . Both pumps have adjustable oilers from the bottom base, about 1/4 turn limitations.
I apologize if I'm beating this to death, and I don't want to keep taking this apart, would the 11356470460 oiling supply, in everyone's opinion, be sufficient?
I may drive out the roll pin out later and see if anything looks out of place. I'm not anti-Stihl dealer, but dealer has a sign out front parts help wanted constantly...

 

[StihlsawuserMS361]

Forgot to add...running 18" RS 66 chains

 

[StihlsawuserMS361]

For what it's worth, I'll pass this along, it may just help someone down the line.
Replaced the oil pump and discharge O ring, then ran a tank of fuel through the saw today. Clutch no longer saturated, same with the frame, handle and chain brake mechanism. Bar is no longer soaked, no puddle under the saw after running. Consumed about 1/2 tank oil to the tank of fuel, which has been the norm since new. Something / somehow happened to the original pump due to the restriction.
Thanks to everyone who chimed in and helped!

 

[Lightning Performance]

For what it's worth, I'll pass this along, it may just help someone down the line.
Replaced the oil pump and discharge O ring, then ran a tank of fuel through the saw today. Clutch no longer saturated, same with the frame, handle and chain brake mechanism. Bar is no longer soaked, no puddle under the saw after running. Consumed about 1/2 tank oil to the tank of fuel, which has been the norm since new. Something / somehow happened to the original pump due to the restriction.
Thanks to everyone who chimed in and helped!

I ran into your issue only one time on a last year of production 361
It had a clogged bar hole feed and dumped oil everywhere even over night. The pump piston was jammed wide open and it did have that 1128 housing number but was using the lesser gear set and a standard control bolt. Just consider the fact that Stihl used what they had available on many saw models that interchange parts.

I found black gum inside the bore end and one tiny wood chip inside the pump. It was also missing the rubber pump cap I do believe.

Pop out that roll pin and have good look in the bore for goo or scratch marks from debris moving through it. That spring is very light and just enough to make it float with thick cold oil. The pump warms up faster that way.

 

[StihlsawuserMS361]

I ran into your issue only one time on a last year of production 361
It had a clogged bar hole feed and dumped oil everywhere even over night. The pump piston was jammed wide open and it did have that 1128 housing number but was using the lesser gear set and a standard control bolt. Just consider the fact that Stihl used what they had available on many saw models that interchange parts.

I found black gum inside the bore end and one tiny wood chip inside the pump. It was also missing the rubber pump cap I do believe.

Pop out that roll pin and have good look in the bore for goo or scratch marks from debris moving through it. That spring is very light and just enough to make it float with thick cold oil. The pump warms up faster that way.

 

[StihlsawuserMS361]

LP,
Thanks for the info. I did start taking the roll pin out of the original pump as others previously suggested, but in seeing I already had a new oil pump decided to go that route. I'd rather not R&R the clutch assembly too many times.
Saw's oiling, as I stated, returned to normal with a new pump.
One of these days I'll dig into the original pump as you suggest, just to learn something.
Thanks again.