028 oil pump/chain lube testing....

[krellboy]

Hi guys....

Wondering if I could get some input on how to test out the chain oil pump on my 028 woodboss. I'm not sure it's working as it should.

If I recall, previously when using this saw I could see oil being "thrown" off the end of the chain. Recently not really seeing this so much....but instead quite a bit of oil under the muffler and dripping down below the chain sprocket when I put it away....seems like it not making it on the chain bar...or if it is, it not very much. Doesn't seem right.

Is there any way to either observe or test out the adequacy of the oil pump function? I can see some oil coming out of the delivery hole but wonder how much I should be seeing and what kind of pressure. I've checked out the supply line and it seems open and the strainer isn't clogged. I've tried to poke a wire into the vent valve as well...not sure it's open.

Before I dig in further to look at the oil pump drive sprocket and maybe remove the pump for inspection a tip would be handy. My repair manual doesn't describe the technique. Furthermore the manual mentions the the "new" P/N for the oil pump requires some trimming of the crankcase if replacing the pump.

Anyway, if someone has come across this issue let me know before I stumble forward with the manual.

Thanks

 

[Mastermind]

Remove the bar and chain......fire it up and check oil delivery at WOT. It should ooze out in a fairly steady stream down the bar pad.

 

[krellboy]

Thanks for the prompt response.

The oil does flow out of the oil hole (by bar pad, you mean the plate that covers the oil hole)...just wonder why I don't see it flying off the chain tip. Also why I have a small puddle of oil that drips below the chain cover and muffler area....maybe just didn't notice it before when last used.

I'll check again.

 

[Bilge Rat]

Clean the bar groove and the oil hole.

 

[trooney]

This^^^^^

 

[krellboy]

Thanks for the responses.

Nothing obvious....bar groove and oil hole both OK.

I own the Stihl repair manual but it's not contributory.....I followed the flow chart and now I'm mainly down to testing the vent hole, which I reemed and the sufficiency of the oil pump, which I don't know how to check.

If I had to guess I'd suppose the pump does not produce enough pressure to put the oil thru the hole and it just seeps behind the cover plate and not enough on the bar.

Hoping avoid taking the oil pump out and inspecting it.....b/c if I go that far I'll probably just replace it. It's not very expensive.

 

[Bilge Rat]

Take the cap off the oil tank and put a puff of about 10lbs of air pressure into the tank vent. You will hear the air coming out of the fill hole of the tank.
Makes sure the oil hole in the bar lines up to the oil slot in the saw.
Use good bar oil.

It is not much pressure just flow.

 

[drf256]

I spent half a day on my 028S oiling problem. In the end, I found out that one actually needs oil in the oil tank for oiling to occur.

True story.

 

[krellboy]

Take the cap off the oil tank and put a puff of about 10lbs of air pressure into the tank vent. You will hear the air coming out of the fill hole of the tank.
Makes sure the oil hole in the bar lines up to the oil slot in the saw.
Use good bar oil.

It is not much pressure just flow.

Thanks for the tip about the vent. I'll give that a try....I actually wondered if I may have boogered it up by trying to reem it out. The repair manual explains how to remove the vent plug but I'm nervous that it may be stuck....given that it's been on there for 20 years. I may try to remove it when i inspect the worm gear if testing the vent valve doesn't work out.

Then again I may just cut some wood and see what happens.....I don't think the chain is dry just not wet enough.