Mcculloch 1-51 - Head Gasket?

[The Burning Rom]

Here's the deal. I found an old 1-51 in a pile of junk at a relative's house. It's obvious that it was sitting out there in the elements for quite a few years, as the chain was one solid mass of rust. Anyway, I brought it home and tore it down. The saw is completely intact (the hard nose bar cleaned up nicely after I got the chain off), though it does need a few things. I found that the recoil is seized (I have since worked it loose), which is probably why it was sitting in the junk pile in the first place. It needs a new chain (obviously), new air filter (haven't found one yet), and a new clutch, which I've already located. I'm sure it could also use a carb kit. But before I stick any money into parts, I want to make sure the piston and cylinder look good. I know it has compression, and I took a peek through the spark plug hole, but I want a better look. Problem is, how do I replace the head gasket once I remove the head? I know McCulloch made a boat load of these 80cc monsters (all the way up through the 250 model), but I haven't been able to locate many parts...most notably gaskets. I split the gas tank, to clean out all the crud that was left after all the fuel evaporated, and it's easy to make a gasket for that. A head gasket is trickier though. I was wondering what you guys do as far as replacing head gaskets for a saw that doesn't have readily available parts??? I'm not going to use the saw for much if I can get it running again. It's just fun to restore something like this...and give it a better existance than it rusting away in a pile of steel. That, and it would come in handy for the times when I'm cutting something that's a bit much for my 011 :greenchainsaw:

Anyway, any info or tips on this matter are much appreciated!

 

[McC]

This guy should have everything you need. I've had good luck with them, and they are willing to help you through it.
http://stores.ebay.com/RANDYS-ENGINE-REPAIR_W0QQ

Scott

 

[cbfarmall]

The older Mac engines I've seen use aluminum head gaskets. I've toyed with the idea of making my own, thinner head gaskets out of aluminum or copper but it never got off the ground. Are you sure your 1-51 has a removable head? I don't recall the 1-41 with one.

Anyhoo, if I were you, I'd pull the muffler and inspect the piston from that side. It'll tell you more than looking at the top of the piston. It's a reed valve motor, so looking through the intake is no help.

Chris B.

 

[The Burning Rom]

This guy should have everything you need. I've had good luck with them, and they are willing to help you through it.
http://stores.ebay.com/RANDYS-ENGINE-REPAIR_W0QQ

Scott

Thanks for the suggestion. I'll check it out.

The older Mac engines I've seen use aluminum head gaskets. I've toyed with the idea of making my own, thinner head gaskets out of aluminum or copper but it never got off the ground. Are you sure your 1-51 has a removable head? I don't recall the 1-41 with one.

Anyhoo, if I were you, I'd pull the muffler and inspect the piston from that side. It'll tell you more than looking at the top of the piston. It's a reed valve motor, so looking through the intake is no help.

Chris B.

I'm pretty sure it has a removable head. There are 4 allen/hex head bolts in the head...spread out around the spark plug.

Pulling the muffler is fine for inspecting the side of the the piston, but it won't help me inspect much of the cylinder. That's why I want to remove the head. Thanks for the suggestions though!

 

[Gearhead1]

For parts, I'd recommend Bob's Lawnmower sevice in Maryland, New York. He specializes in parts for older McCulloch saws, and has been a big help to me many times. If you do a search, you should be able to find his phone number listed in another post in this forum. Maybe one of the other members has it handy too....
McCulloch made those engines both with and without headgaskets, but I'm sure your saw has one if it has the four bolts you mention. The later saws were of the "headless" design, so a 1-51 was probably one of the last models with separate head. What I'd recommend you do though, is to repair the starter, and then give the saw a compression test. The comp test will show the picture at a glance of sealing condtion for the cylinder (rings, piston, cylinder wall).

 

[The Burning Rom]

For parts, I'd recommend Bob's Lawnmower sevice in Maryland, New York. He specializes in parts for older McCulloch saws, and has been a big help to me many times. If you do a search, you should be able to find his phone number listed in another post in this forum. Maybe one of the other members has it handy too....
McCulloch made those engines both with and without headgaskets, but I'm sure your saw has one if it has the four bolts you mention. The later saws were of the "headless" design, so a 1-51 was probably one of the last models with separate head. What I'd recommend you do though, is to repair the starter, and then give the saw a compression test. The comp test will show the picture at a glance of sealing condtion for the cylinder (rings, piston, cylinder wall).

Thanks for the suggestions. I took the saw over and had my dad look at it, since he fixes pretty much anything with a motor. He took a quick look and pointed out to me that it indeed does have an aluminum head gasket...in the form of a large plate sandwiched between the head and cylinder/saw case. Upon further close inpsection, it is not part of the cylinder casting and is indeed a gasket. So that answers the headgasket question...the aluminum one should be good. And if it isn't, I can always make a new one

I have another question though...that I'll ask in this thread before starting a new one. When I split the gas tank, it had a lot of crud (which I assume is the residue the oil left after the gas evaporated. I bead blasted the front part of the gas tank, which revealed that the gas had eaten a hole in the bottom of the housing. I have to rig the saw up to bead blast the other part of the tank...rather than removing it. When I bead blasted the cover though, the black stuff that was coating the tank (and I assume protecting the aluminum from being eaten) went with it. In my defense, it was already peeling off before I blasted it. My question is, does anyone have a suggestion for a replacement coating? I know they have gas tank sealer that you dump in and swish around, but that wouldn't work in this case since the tank has a seam in it (and I'd have to take it apart after the 'swishing' to put the fuel pickup back in. I need something that can be sprayed/applied before the tank goes back together. Once again, any suggestions are much appreciated!

 

[PES+]

I use POR silver paint but you need to be REAL careful not to get it on the mating surfaces cause it is a PITA to remove it after it dries if you do...I brush it on and then quickly wipe off any on the edges of the mating surfaces then let it dry so that the wells are down so no chance of runs making it to the mating surface it seems to hold up really well to even alky nitro mix as long as it is flushed after and there is no raw aluminum or magnesium showing.

A side note.....we used to use the aluminum ashtrays from Burger King for head gaskets for the old Macs.....just the right diameter and were easy to roll out flat and punch. See what we are missing now with the new smoke free society?

 

[Gearhead1]

I've used something called "Seal-All" before on pits in a fuel tank like you describe. You ned to apply it in thin coats, but it is possible to even seal small holes through the casting. I think you'd be able to find it in most hardware stores--it comes in a yellow and red tube (maybe 4 oz).

 

[The Burning Rom]

I use POR silver paint but you need to be REAL careful not to get it on the mating surfaces cause it is a PITA to remove it after it dries if you do...I brush it on and then quickly wipe off any on the edges of the mating surfaces then let it dry so that the wells are down so no chance of runs making it to the mating surface it seems to hold up really well to even alky nitro mix as long as it is flushed after and there is no raw aluminum or magnesium showing.

I have a Black POR kit and a Grey POR kit here that I've never used. Does the color really matter? Thanks for the suggestion by the way. I might finally use this stuff that I bought to use on one of my cars (which I no longer have) a few years ago.

I've used something called "Seal-All" before on pits in a fuel tank like you describe. You ned to apply it in thin coats, but it is possible to even seal small holes through the casting. I think you'd be able to find it in most hardware stores--it comes in a yellow and red tube (maybe 4 oz).

Is that something you can get from most hardware stores or automotive stores (like Bumper To Bumper)?

As for the holes in the lower corner of the casting, I'll probably plug those with some JB weld.

Thanks for the suggestions!

 

[McC]

JB weld works great to repair holes like that. I've used it a lot.
Scott

 

[The Burning Rom]

JB Weld it is! I have to get all of this gas tank sealant off first. The bead blasting took most of it off...but they're still a bit holding on that I have to loosen up with a screwdriver. I'll get that cleaned up early next week and coat the tank. Then I can put it somewhat back together and see if I've got some spark. I can't wait to test fire this beast

Here's some pics of the progress. The bar cleaned up real nice. It's only worn on one side. Whoever owned it must not have known to flip it.

The front cover for the gas tank is interesting. If you look at the picture, it almost appears as if Mcculloch originally intended for the oil tank to be below the gas tank...at least that's as much as I can figure. Either that, or there was supposed to be a primer button on the left side (looking at the picture) of the cover. Anyone know for sure what the story about it is?