McCulloch Power Mac 310 Leaking crank seal symptoms.

[Stihlcutting]

Hi, I have a Power Mac 310 that I am trying to revive. squirted some two-stroke fuel into the carburetor and the saw ran for a brief moment. So, I figured it was worth a look. Pulled the carburetor and found the diaphragms were a little stiff. Put new ones in and a new impulse hose. the fuel line was good. It started and was very responsive. However, it began to run high and was slow to return to Idle which seemed a little high. I also noticed if I turn the saw so the drive side is facing down the idle would come down and I would have to keep it running with the throttle. If I turned it so the starter side is down the saw would start to race. I have tried to richen both low and high adjustment with no luck as well as adjusting the idle speed. It is acting like this consistently. Does this seem like a bad seal one the drive side of the crank? Or is there some other issue that I should be looking into. Have not done a vac\press test on it but probably will.

 

[hacskaroly]

Does this seem like a bad seal one the drive side of the crank?

I would say yes, it does sound like an oil seal leak. I have a couple of saws that have done that, turn it onto its side and it starts running up.

 

[Stihlcutting]

It looks like they are easy enough to replace. I will probably go ahead and order them. Thank you for confirming my suspicion.

 

[heimannm]

I have the seals available if you cannot find any locally.

Also check the fuel line and filter, if the fuel pick up is out of the fuel when you turn it on its side it can behave the same way.

Check in intake boot as well, it could be that changing positions is causing a crack in the intake boot to open up.

The ergonomics on the 310/320 saws are not very good, but the engines do run very well when everything is in good shape. The 334/340 are much better ergonomically, but are too ugly to actually use in public...



There are two at least two dedicated McCulloch threads in the "Chainsaw Stickies" area that are suitable for your questions and follow up if you want to get additional inputs.

Mark

 

[Al Smith]

As a comment most mini's come in two types those that run and those that used to .In good running condition for their small size they do very well .However if you have to work on the early ones like the 110 they will tax your patience .Later they were not too bad .

 

[Stihlcutting]

I have the seals available if you cannot find any locally.

Also check the fuel line and filter, if the fuel pick up is out of the fuel when you turn it on its side it can behave the same way.

Check in intake boot as well, it could be that changing positions is causing a crack in the intake boot to open up.

The ergonomics on the 310/320 saws are not very good, but the engines do run very well when everything is in good shape. The 334/340 are much better ergonomically, but are too ugly to actually use in public...

View attachment 447336

There are two at least two dedicated McCulloch threads in the "Chainsaw Stickies" area that are suitable for your questions and follow up if you want to get additional inputs.

Mark

I have found a set of seals, and they are on their way. I didn't think about the fuel in the tank causing any problems, I just put enough in to start it and run for a few minutes, but I think that isn't what is causing the issue because of how quickly it reacts to the position of the saw. I will pull the filter and inspect it then run the test again with a full tank just to cover all my bases though. Before I started working on the saw, I had cleaned everything up and gave it a visual inspection. The intake boot looked to be good and flexible. Since I will be getting the seals, I will give the intake a closer look while it is apart. Thank you for your information it is very much appreciated.

 

[Stihlcutting]

As a comment most mini's come in two types those that run and those that used to .In good running condition for their small size they do very well .However if you have to work on the early ones like the 110 they will tax your patience .Later they were not too bad .

I have an (probably unhealthy) obsession to get things that are broken working again. Sometimes I save money and sometimes it costs more than it's worth but there's the experience. Right? This saw was given to me by a friend. It was well taken care of, so I thought it was worth fixing. I pride myself in the level of patience that I have while working on things. I have mastered the "walk away and regroup" method of repair work. It has saved me many parts and tools. I find it interesting to see the engineering put into these machines.

 

[hacskaroly]

I have an (probably unhealthy) obsession to get things that are broken working again. Sometimes I save money and sometimes it costs more than it's worth but there's the experience.

This describes probably all of us on this forum...

 

[Al Smith]

For that matter I do it for the challenge and I always win but some times I just have to walk away and come back later .I might add all my mini's were gifted ,I don't have one thin dime in them .Several had the original 14" bar and chain that had never been filed .At some time or another they decided not to start and got relagated to some portion of a barn,shed for 25-30 years .BTW I have a tuned pipe 120 with a trombone slide style pipe. For a mini it's fast but not practical and noisey enough to wake the dead .

 

[Stihlcutting]

For that matter I do it for the challenge and I always win but some times I just have to walk away and come back later .I might add all my mini's were gifted ,I don't have one thin dime in them .Several had the original 14" bar and chain that had never been filed .At some time or another they decided not to start and got relagated to some portion of a barn,shed for 25-30 years .BTW I have a tuned pipe 120 with a trombone slide style pipe. For a mini it's fast but not practical and noisey enough to wake the dead .

Yes, the challenge and the feeling you get when you win! is a powerful driving force. Also to be able to pinpoint the cause of the issue without throwing a bunch of parts at it is satisfying. The mini sounds interesting. Would like to see a pic of that.