MS290 Oiler Issues

[FlyingDutchman]

Put a new, hotter top end in an old and tired MS290 saw. Saw has a new 20" Tsumura bar, new Stihl chain. .325 .063 gauge. Old was .050 3/8. Maybe 5 tanks on the new B&C.

It flows JUST enough oil to continue to cut, the bar gets hot in dry wood. Instead of a 3" round spatter at the end of the bar, its a cloud of "mist" around the outside about 10" around that hits the cardboard.

I had it apart before switching the B&C to confirm I had the pump drive installed properly. Gear drive looked okay.

I dumped the tank and rinsed with premix and ran premix through the oil pump for about 10 seconds, no alarming amounts of debris came out of the tank (filtered with a cloth). Cleaned the bar passages, etc. Oiler is adjusted to max. After 1 tank, I barely use 1/4 tank of oil. The filter on the oil tank does not have a long enough hose to get it out to inspect it, unless I'm missing something.

What should I look for before I replace the oil pump on this saw? Is there an upgraded pump to flow more? a hidden place debris piles up inside the pump?

 

[user 122190]

You can try drilling out the oil hole on the Tsumura bar. My 7yo ms290 oiler lays it out thick. I have it set at 1/2 and that is about perfect for my 18" bar&chain.

I have never removed the oil filter. The hose does seem a bit short, but that would be a nice place to start, if you can figure out how to get at it easily.

 

[HarleyT]

Have you tried the adjustment? It may be turned too low.

 

[cuinrearview]

Confirm the paths for oil on the new bar match up and are clear.

 

[FlyingDutchman]

Have not checked how the oiler passages line up. The bar was originally destined for an 026 Super Stihl due to the pitch and gauge. Good point, will check. The hole for the oil to flow through is small, will compare to the original bar.

Oiler is turned all the way up. I could try turning it the other way?

I cleared the passages this weekend and still had issues, and debris that I would have thought would have been cleared away by oil.

 

[user 122190]

I drilled out my Forester Platinum bar on my ms461. Seems to have made a difference, but I went ahead and made the mods to convert the standard oiler into a high output oiler. Big difference. It is at 1/2 for the 24" bar, and I will turn it to full for the 32" bar.

Drilling might keep the passage from getting clogged up, but in a clean passage, increasing the diameter probably won't make enough of a difference. At least that was not my experience.

 

[SteveSr]

a hidden place debris piles up inside the pump?

Yes, I have seen this on an 026/MS260. The pickup in the tanks is just a screen so it will pickup debris from the tank. Hopefully it will flush through but not always, especially if the saw sits a lot and the oil/debris starts to gel.

Put up a pic of the front and back of the pump to see if there is a way that it can be disassembled and cleaned. Some of the 026/MS260 pumps had drift pins that could be driven out to disassemble.

Flushing these while assembled is difficult as there is no straight shot through the pump. You need to somehow simultaneously run the pump while forcing oil through it.

 

[FlyingDutchman]

Tore it apart, cleaned it up blew a bubble with the compressor into the tank and got a nice fountain of oil back out. Blew through the passage to the bar. Clear. I added an o ring to the plastic arm on the oiler port for extra sealing, it was a little loose. Turned the pump by hand for a long time, I do get flow eventually but it took maybe 10 minutes of hand turning to fill the plastic groove next to the passage.

I could see inside the inlet and outlet of the pump and no debris, but didn't see a way to tear apart the pump, looked pressed together. Have a feeling will still have low flow when tried.

 

[SteveSr]

I could see inside the inlet and outlet of the pump and no debris, but didn't see a way to tear apart the pump, looked pressed together. Have a feeling will still have low flow when tried.

I am assuming that this is an OEM pump. Take a look at the screw adjustment shaft and you should see a small 1/16" roll pin visible from both sides. Press this pin out and then work the adjustment screw out of the housing about a 1/4". This should free the pump plunger shaft to move towards the adjustment shaft enough to provide a direct path through the pump. Be careful with the adjustment shaft as it has an o-ring on it that keeps it tight in the bore.

Now hit the input and/or output with pressurized carb/brake cleaner followed by compressed air. This should clear out any crud that is collected in the plunger end of the pump. You may want to put a catch rag over whatever end is the output so you can see what debris comes out. The key here is solvent / pressure / velocity which you can't get with the pump fully assembled.

 

[FlyingDutchman]

SteveSr, yes it has this roll pin, will clean as you advised and report back!

 

[FlyingDutchman]

Looked really really hard for the smoking gun debris but didn't see it when I blew it out. Sure enough, upon reassembly I got more stroke out of the oiler shaft. The way it's driven is definitely goofy.

The worm gear on the crank drives straight gears on the shaft. As the shaft turns, a spring pushes the shaft against the eccentric dowel pin that is the stroke adjustment for the oiler. There are chunks cut out from the end of the shaft. As it turns then, it creates and in and out pumping motion while the eccentric pin in and out motion on the ground away places on the shaft.

The debris prevents this motion from having full stroke. Thanks SteveSr!!!

 

[FlyingDutchman]

When sweeping last night, I found a tiny little washer like on the pump shaft behind the spring. Is there a possibility that there are two washers on the pump shaft or did it fall out while cleaning?

 

[SteveSr]

When sweeping last night, I found a tiny little washer like on the pump shaft behind the spring. Is there a possibility that there are two washers on the pump shaft or did it fall out while cleaning?

Don't know... You'll have to compare it with another good pump or find photos if it is visible with the pump assembled. If it is the correct I.D. and O.D. then I would suspect that it goes in there somewhere. What do the wear marks look like on each side of the washer? does it look like something was rotating against it?

 

[FlyingDutchman]

There is a washer on each side of the spring. The spring would wear into the soft pump housing while it spun if you left the washer out, already noticed some wear in the pump body with the washer out with less than a tank through it! Hopefully it still means the pump will work, now though. Its time for this money/time pit saw to do some work for once.

 

[user 122190]

There is a washer on each side of the spring. The spring would wear into the soft pump housing while it spun if you left the washer out, already noticed some wear in the pump body with the washer out with less than a tank through it! Hopefully it still means the pump will work, now though. Its time for this money/time pit saw to do some work for once.

In doing such work I usually print out an exploded parts diagram. I do remember looking at the diagram and noticing the two washers and kept an eye out for them when I upgraded the oiler in my 461. You were lucky to have found such a small part in the swept up floor debris. I regularly have to look for small parts in such mess. You found it and you weren't even looking for it. Well Done!

 

[FlyingDutchman]

Thanks MontanaResident! It was clear on the other side of the garage almost, air compressor send it for a ride, even though I tried to capture all the debris in a rag to see what was in there. I could not find an exploded view of the part, or a tutorial video, it is simply replaced.

 

[user 122190]

Thanks MontanaResident! It was clear on the other side of the garage almost, air compressor send it for a ride, even though I tried to capture all the debris in a rag to see what was in there. I could not find an exploded view of the part, or a tutorial video, it is simply replaced.

Years ago I spent hours on the floor looking for a tiny spring to a Beretta pistol. Those little parts are evil and can and do bounce for a long ways in a zig zagging path. Back then the dog was a puppy and it was fun for her to attack me as I did the search. I was happy to find it, as it probably cost 50c, but likely $7.95 to have it shipped.

 

[FlyingDutchman]

Yikes, plus puppy attacks! Yeah, happy I found it. A spring wouldn't glint off the lights like this little washer did.

Really eager to use this saw. Its been either low on power because it has bad oiling or bad carb adjustment. Eager to see if I can get some power from her and see if my work paid off.

Hows your ported saw running?

 

[user 122190]

Yikes, plus puppy attacks! Yeah, happy I found it. A spring wouldn't glint off the lights like this little washer did.

Really eager to use this saw. Its been either low on power because it has bad oiling or bad carb adjustment. Eager to see if I can get some power from her and see if my work paid off.

Hows your ported saw running?

All my saws are stock. If the saw(s) is not cutting to my satisfaction I sharpen the chain.

 

[FlyingDutchman]

I thought you did a bigbore on your 290, sorry