Small Engines (Lawn Mowers, etc.): Stihl MS390 Chain saw, husqavarna chain saws, chain oiler

Question
QUESTION: I have acquired a Stihl MS390 chain saw and discovered that the chain had been overheated and could not be adjusted up sbug. After replacing the chain I can now adjust the chain for no sag.

The problem seems to be in the oiler system, I had a service center look at the saw and and with the bar and chain off very little bar oil was being discharged from the oiler hole. The service guy looked at the oiler worm screw (Plastic) and it appeared okay. He checked the oil filer and hose (Okay) after reassembly it had aprox 3 times more oil flow.

I ran across a tip that suggested to drill the oiler hole slightly larger which I have done to see if I can improve the oil flow.

Any other suggestions as to how to increase the oil flow to the chain. I failed to mention that I have the oil adjustment on the bottom of the saw full open. Bard guides and oil ports are all clean.

ANSWER: Hello Dale:

>>It the Oil Pump is Pushing at Maximum and you have Enlarged the Chain Oiler Outlet Port to a Point that it Uses Almost 1 Tank of Oil to 1 Tank of Gas, then the Bar should be Getting the Proper Amount of Oil Required.
>>The Oil Pump May be Pushing Oil through the Oil Port, Just Not the Correct Amount.
>>I had 1 that had a Similar Problem and Replacing the Oil Pump Corrected the Problem After the Oiler Port was Drilled. The Old Pump was Pumping, but Not the Amount it was Designed to Pump.
>>I Stopped Purchasing Sthil Chain Saws for this Very Reason. People can Say what they want to About Poulan and Husqavarna Chain Saws, but I have Several and have had Little to No Problems with them Other than on a Couple of them I have had to Drill the Oil Port to Get More Oil to the Bars.
>>Please, Do Not Hesitate, If you Hit a Snag, if I Missed Something or this Does Not Correct the Problem, I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Thanks.

Good Luck

Respectfully

John

>>PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Comments and Ratings are Greatly Appreciated. Thanks.

Respectfully

John


---------- FOLLOW-UP ----------

QUESTION: Hi again John,

Thanks for your timely response to my original question regarding the chain oil.

Just to follow up, I did not mention that I got the saw used and therefore have no history on what problems it may have had in the past or how well it was taken care of.

What prompted me to look at the oil situation in the first place was a chain that needed to be replaced as a result of heat.

After replacing the chain with a new one I paid particular attention to insure that everything I could learn about the oiling scheme was working. I cleaned the oil holes in the bar including the chain guides. I however don't have any knowledge of what kind of oil was used in the past.

I know of some folks who claim they use, used motor oil as bar oil, even as a novice at this chain saw business it would seem that dirty oil would only tend to clog things up and doesn't appear to have the staying power that bar oil has.

I can't comment on any success or lack of it with the oil hole enlargement for the chain lubrication as I haven't been able to run it long enough to tell.

The only thing left to try if all else fails is to have the oiler pump replaced, but I understand it could be expensive and I wanted to exhaust every thing else first before going to that expense on a used saw. The pump is a logical  suspect but at least is at pumping, I can't say if it is at it's full potential but given every thing else I found relating to the chain lube problem I figure it would be wise to at least eliminate those first before a pump replacement.

Soon I will have an opportunity to give the saw a work out and see if the problem still persist after all I have done, if the problem persist then I guess the pump will be the final item to replace in effort to keep the chain lubricated.

I'll let you know what I find in the days to come, thanks very much for sharing your knowledge and expertise.  

Answer
Hello Again Dale:

>>I Suggest you Enlarge the Oil Port if there is Not Enough Oil going to the Bar. Wait Until you can Operat the Saw Enough to See if it is Using Approx 1 Tank of Oil to 1 Tank of Gas.
>>You can Use SAE50 Engine Oil if Required, but Burnt Cylinder Oil is a No No.
>>Thanks for the Update and Look forward to Hearign from you Again.

Good Luck and Best Wishes

Respectfully

John