Help with a McCulloch PM610 Oil Tank

[LilRobert1367]

I need help with a cracked oil tank on a McCulloch PM610 right at the chain adjuster. I was wonder if anyone can suggest anything I can do to repair it without out replacing the oil tank. I want to keep the chainsaw all original if I can since it was my grandfathers.

 

[heimannm]

You might want to figure out why it cracked in the first place. If I had to repair one like that, I would clean the inside of the tank thoroughly, roughen the surface, and apply a layer of J.B. Weld. If it is a structural issue, press a piece of window screen or hardware cloth into the J.B.

I have repaired rare oil tanks and even a crankcase with J.B. Weld and all are still working.

Mark

 

[Cliff R]

They made ZILLIONS of PM-610's and they are still readily available and dirt cheap as non-runners.

An epoxy type repair there would be temporary. I would imagine the studs were pulling on the case and cracked it from years of loosening/tightening the bar nuts when changing and tightening chains.

Unless a structural repair is made it will just get worse........IMHO. I'd grab another saw and replace the entire tank/case.........Cliff

 

[LilRobert1367]

Mark, I really can't ask my grandfather how the crack got there in the first place since he is no longer with us, all I can do is guess at why its there in the first place. Also I want to stay away from JB just because of the location of the crack. I feel like its just going to be a temporary fix and its going to crack again.

You might want to figure out why it cracked in the first place. If I had to repair one like that, I would clean the inside of the tank thoroughly, roughen the surface, and apply a layer of J.B. Weld. If it is a structural issue, press a piece of window screen or hardware cloth into the J.B.

I have repaired rare oil tanks and even a crankcase with J.B. Weld and all are still working.

Mark

 

[Ronie]

You could try and find a welding shop that can tig weld it.

 

[LilRobert1367]

Cliff, I want to keep the part close to original to this chainsaw as I can so I can keep the scuffs and dings he originally put on it. Call it sentimental if you want but I really don't want to have to buy another one just for the oil tank.

I do agree with you on any epoxy repair is going to be a temporary repair, that why I joined this forum to see the advise I would get since every where else suggest JB weld. Would brazing be a better structural repair or is having someone that knows how to weld aluminum a better opinion in your opinion?

They made ZILLIONS of PM-610's and they are still readily available and dirt cheap as non-runners.

An epoxy type repair there would be temporary. I would imagine the studs were pulling on the case and cracked it from years of loosening/tightening the bar nuts when changing and tightening chains.

Unless a structural repair is made it will just get worse........IMHO. I'd grab another saw and replace the entire tank/case.........Cliff

 

[Ronie]

You would need someone that can braze or tig magnesium.

 

[Cliff R]

Using JB Weld on a repair of that type is similar to cutting your arm off and putting a bandaide on it.

I see it used widely as we work on all sorts of mechanical things for a living, and for anything that flexes, and heats/cools, etc, welding or brazing will be a much better long term fix.

I'd also add that when we choose an epoxy repair here, we use Marine Tex, especially if fuel or oils are involved......Cliff

 

[heimannm]

If you haven't used J.B. Weld correctly you have no idea what you are missing.

BP-1 oil tank





Solo Twin crankcase - corrosion went all the way through the crankcase.





Dolmar 166 AKA McCulloch SP118







Ask someone who's run any of theses three saws whether these were temporary repairs.

You cannot braze magnesium, and you will find it nearly impossible to make a decent tig weld since the magnesium is somewhat porous and will have oil absorbed into the metal itself.

Since you won't heed my recommendations, I'll move on to other threads where someone might actually consider the advice they have asked for.

Mark

 

[LilRobert1367]

Ronie Thanks for that advice. I didn't realize it was magnesium I thought it was aluminum but that is good to know. Thanks again.

You would need someone that can braze or tig magnesium.

 

[Ronie]

Your welcome, good luck

 

[Ronie]

Your welcome, good luck

 

[LilRobert1367]

Cliff I agree with you. The fact that its where the bar connects with the motor is the issue I have with using JB weld or an epoxy in general since all the force on the bar is focused right there and I don't think epoxy is the right answer. I don't want to put my faith on epoxy since I do want to use the chainsaw when its fixed.

Using JB Weld on a repair of that type is similar to cutting your arm off and putting a bandaide on it.

I see it used widely as we work on all sorts of mechanical things for a living, and for anything that flexes, and heats/cools, etc, welding or brazing will be a much better long term fix.

I'd also add that when we choose an epoxy repair here, we use Marine Tex, especially if fuel or oils are involved......Cliff

 

[NeSurfcaster]

Lots of people forget that a long lasting jb weld/epoxy fix involves a lot of prep. Like in Marks pics you can see how clean the surface is. Sanding/grinding/brake clean are all necessary as well as sometimes drilling holes in the ends of the cracks so it can't spread.
Marine tex is pricey but works very well, many stories about crazy repairs marinetex has made.

 

[Cliff R]

Epoxy's such as JB Weld or Marine Tex are OK for some metal repairs, but not when things can move around or flex.

JB Weld is not good for holding back fuel, might be OK for bar or lube oil. Marine Tex holds up better in constant contact with gasoline.

I've worked on over 13,000 carburetors in my shop to date and every single one repaired with JB Weld to seal up bottom plugs leaks right thru it. This actually amazes me because some of the repairs look perfect and the epoxy still appears to be well attached to the base material. In reality the JB Weld simply doesn't stay attached to the base material after many hundreds of heating/cooling cycles.

The best repair here is to get another tank.....IMHO......Cliff

 

[SmellyPirateHooker]

These things can be had so cheap I'd just buy another one for parts. Most are sold as needing repairs due to oiling issues or bad cylinder also because of bar oiling issues. Cases are usually good.

 

[LilRobert1367]

I thought I would do a update on this and say that I actually found another 610 in my grandfathers garage in a cabinet buried under a bunch of stuff that my grandmother thinks was my great grandfather saw but wasn't sure. So I took the oil tank off of that one and put it on the one that my grandfather used that I am rebuilding. Its not mcculloch yellow, it painted black but it was still in my grandfathers stuff so I am considering still part of my grandfather saw.

It was actually nice to have this other 610 since I found some other problems with the one that I am rebuilding. The piston and cylinder was scored pretty good at the exhaust port and the piston rings was locked in the grooves so the compression was **** on it. I took the cylinder and piston from the other 610 since that was in great shape and put it in the one that I am rebuilding. I didn't expect to find another 610 in his garage but I am glad I did. I would like to thanks to everyone that responded to my question. Thanks again.