Repairs MAC 3216 Pumps Too Much Bar Oil


Forum Newbie
Jun 5, 2015
Hello MAC Chainsaw Gurus -

I hope there are still some out there anyway.

Two years ago I was given a MAC 3216 16" chainsaw that hadn't been used in some years; it appeared almost new.
Checked it out & found bar oil in the gas tank. Mighta been the reason it wouldn't start. Cleaned it up, replaced the bad fuel filter and lines (except for the black line from carb to primer (Primer Retain). Replaced the bad oil line to the pump & cleaned the oil filter. Bought two new chains for it.

It cranked almost immediately, and used it for about 5 min, then it quit running. The Primer bulb had split and the Primer Retain line broke. Couldn't find the MAC part for that line, so put it on the shelf. Fast forward 2 years.

Had a big shrub job come up, so thought I'd see if I could get it going again. Still couldn't find the MAC part for the Primer Retain but a tech said just use Tygon. Why not? Bought an Oregon bulb kit w/a section of fuel line; hooked it up. Primed well & started up. Had the bar off to look for oil moving; took 5-6 revs but then saw oil coming out of the oil port. Great (I suppose).

Mounted the bar & chain, cranked it up and oil soon began to appear on the chain. So far so good. Revved it a few more times, and saw more oil on the chain. A few more revs and the chain was soaked with oil. Mmmmm. Then it started dripping oil from below the sprocket about one drop every 6-8 seconds when revved, and the chain was slinging oil. Aaaaargh.

Decided to use it anyway. Cuts great but found out it goes thru two tanks of bar oil per tank of gas - a bit much, I think.

In looking at an IPL for this 3200 series, I noted a duckbill valve and a piece of foam that go into the oil tank. So ...
1. What is the purpose of the duckbill valve?

2. Is it possible that the valve is bad and/or the foam deteriorated (very possible) such that the assembly is allowing too much oil output than it should?

3. What else could be causing this excessive oil flow?

Any help will be appreciated.



Lawn Pro
May 6, 2010
The 32,35,38 series all have the oil pump behind the flywheel which makes it a continuous pump system, meaning it pumps oil even when the chain isn't turning. There is no adjustment available. the duck bill valve is for tank venting and nothing else. As far as fuel line, any repair ship that works on trimmers should have the tygon fuel line in bulk, I buy it in 50 foot rolls. After Husqvarna purchased Mcculloch back around 2005 they have killed off the entire line, and there are no parts available that I can find at least through Mcculloch distribution.

ILengine, Mcculloch service center since 2000


Lawn Royalty
Nov 29, 2014
Some parts are available from aftermarket suppliers but I get most of my bits from Randys.
Reasonable price & huge inventory.