McCulloch Pro Mac 700 ("the Professional") Guide Bar Bolt

[Gil Wirt]

My saw's forward guide bar bolt is turning with a stuck nut now (ugh) ....

I guess I need to grind off the nut first (or vice-grip[if possible] bolt and try to twist nut off)...

HOW IS THE GUIDE BAR BOLT UNDERSIDE RE-ATTACHED?

I'm guessing that will need to be welded?
That's magnesium(crankcase)...mig-welder needed?

Gil Wirt

 

[emf123]

It's a squared head bolt captured inside the oil tank. Take off the front cover and you should be able to get a good look at it.

 

[Gil Wirt]

It's a squared head bolt captured inside the oil tank. Take off the front cover and you should be able to get a good look at it.

Squared head top bolt that broke through...a holder/casing...a weld? How is that square top held in place? [I'll do as you say; I wonder how to fix/have-fixed]
What is the best path to re-fix that, and how best to get that nut off(metal grinder for my Dremel Multi Max is all I can figure; my carbide blade/skilsaw is too heavy to be precise[I'd damage the bolt])? -Gil Wirt

 

[heimannm]

May be easier to replace the oil tank with one that has good studs. Make sure to get one from a similar saw so you have all the right mounts and fittings.

Mark

 

[Gil Wirt]

Thanks emf123 and Mark(know you as a mac guy from some of your posts) for help; my two strongest saws (biggest and heaviest, too, but I don't mind) are this 700 and an E.B.3.7; I like them a lot; I harvest wood(Juniper around where I stay for now, 'plan to get a Nat'l Forest permit to harvest later) for heat/cooking in winter; I have done only minor work on saws, with uneven results; I can see some tanks on ebay now: PM600 series(E.B. inc'd.) and one pm 850 one;
ANY IDEA WHICH ONES WORK(could fit the pm700)??['does not look like too tough a fix{famous last words haha ugh}]

Thanks in advance, Gil Wirt

 

[heimannm]

Any of the 10 Series PM saws from the PM60 on up, PM700, PM850, 800, 805 would be a drop in match as they all have the bearing insert (sleeve) on the PTO side. I think (98% positive) that any of the 10 Series SP model tanks would also work. Avoid any thing from a saw smaller than 60cc since they wont have the bearing insert and the crankcase bore on the PTO side won't agree. I looked through my photos and don't find any that show the bearing insert but basically is it an aluminum sleeve that fits over the bearing; the bore in the crank case is also oversize to accommodate the bearing insert.

I have swapped several oil tanks on the 10 Series both with and without the inserts and only had one case (DE80) where I could not get the case to seal up properly. I don't run my saws 8 hours a day so I will never know it there was a little misalignment of the bearings due to the bores not being machined in the same set up.

Mark

 

[Gil Wirt]

Any of the 10 Series PM saws from the PM60 on up, PM700, PM850, 800, 805 would be a drop in match as they all have the bearing insert (sleeve) on the PTO side. I think (98% positive) that any of the 10 Series SP model tanks would also work. Avoid any thing from a saw smaller than 60cc since they wont have the bearing insert and the crankcase bore on the PTO side won't agree. I looked through my photos and don't find any that show the bearing insert but basically is it an aluminum sleeve that fits over the bearing; the bore in the crank case is also oversize to accommodate the bearing insert.

I have swapped several oil tanks on the 10 Series both with and without the inserts and only had one case (DE80) where I could not get the case to seal up properly. I don't run my saws 8 hours a day so I will never know it there was a little misalignment of the bearings due to the bores not being machined in the same set up.

Mark

Thanks Mark for the tips...wow to the technical expertise to re-fit the tank around the bearings; I had seen the shape of those tanks(cited), which I figured worked(PM 6 series oil loads on side, looked wrong)...and will likely try to have the piece that broke off(I opened tank and looked last pm) welded in place or jb-weld that if a welder does not want to tackle that. -G.W.

 

[heimannm]

It's not really that difficult. Clean both surfaces, apply a light coat of your favorite fuel and oil resistant sealer (I use Threebond 1184), and put it back together. The seal on the flywheel side is in the bearing race so no challenge there. Lately I have been installing the PTO side seal but leaving it slightly out from its final position, then finish pressing it home once the case halves are back together. I have a few 6112 seals on hand that don't have a nice taper on the back edge so they don't want to slip into the bore if you put the case halves together first. OEM seals and most of the 6119 double lip seals have a better tapered edge and a heavier steel body.



There are four 12-24 x 1-3/4 bolts (technically cap screws) in the bottom of the oil tank, and four 8-32 screws on the flange with two above and two below the crankcase. This happens to be a 1-10 with manual oiler only so there is no automatic pump, just the check valve you see below.




Mark