Finally started this McCulloch BP-1 project, need some parts and advice....

[Scotty Overkill]

I'm not sure how many if yinz ever built one of these unique saws, but the way they did the intake ports is quite different from any other saw that I've seen in my day ....

The ports were drilled from the outside of the cylinder.......there are little plugs epoxied into the outer jug to fill those open holes. Well, the BP-1 I currently have on the bench has an excellent jug and piston, but one of those little port plugs is gone. Wondering if I should make a new aluminum plug and "mushroom" it with epoxy into that port hole, or should I just TIG weld the facking thing shut?

What say yinz fellas?

Sorry, no pic's at the moment as my phone died while I was working in the shop last evening, I'll try to get some tonight or tomorrow.

And while I'm at it, does anyone have any spare parts they'll get rid of for these BP-1's? I have almost enough stuff to build two of them. the one on the bench now will be my experimental saw, as I'm fabbing a carb box and linkage to accommodate a more modern carburetor. The original flat carbs for these saws are obsolete and parts to rebuild them just don't exist....

 

[Dub11]

 

[p61 western]

Subbed this is going to be good.

 

[p61 western]

I think @jacob j. Has experience with these.

 

[Scotty Overkill]

Make a big bowl, and some extra salt and butter....lol

 

[Scotty Overkill]

Subbed this is going to be good.

Trust me, it'll run one way or another. If I have to use my other jug, I will. It's not quite as nice but it'll work....

 

[p61 western]

Cool project, and thank you for sharing Scotty.

 

[David Young]

pics of the missing plug

I think you are talking about the transfers?

you could do as you said and epoxy an aluminum plug in or possibly just jb weld it self.

you may want to fill the back area with wax to keep the epoxy where you want then melt the wax after you are done.

 

[Scotty Overkill]

pics of the missing plug

I think you are talking about the transfers?

you could do as you said and epoxy an aluminum plug in or possibly just jb weld it self.

you may want to fill the back area with wax to keep the epoxy where you want then melt the wax after you are done.

Yes, I meant the transfers.
I'm at work now, so the pics will have to wait.
I'm leaning towards getting an aluminum plug made on a lathe with a small shoulder on one side, putting it in from the inside with a bit of epoxy, and using a center punch to dimple it from the outside, hence "mushrooming" it in place.

 

[jacob j.]

I think @jacob j. Has experience with these.

It's been around 15 years since I've worked on one, but yeah those plugs in the cylinder are common on most McCulloch engines of that era, due to their manufacturing processes. They're an SAE sized plug similar to freeze plugs on American made automobile engines. Measure the hole and you should be able to find a suitable replacement. JB Weld is fine for setting them. Two of my 125s got all the plugs replaced and set with JB Weld.

 

[Scotty Overkill]

Here's the "as purchased" pics. Mostly complete saw, great compression, hot spark, but someone put a Tilly HL carb on it years ago. It's seen better days, but at least it exists...







And here's some "before teardown" pics of the saw.....it's completely disassembled at the moment.....

 

[Scotty Overkill]

It's been around 15 years since I've worked on one, but yeah those plugs in the cylinder are common on most McCulloch engines of that era, due to their manufacturing processes. They're an SAE sized plug similar to freeze plugs on American made automobile engines. Measure the hole and you should be able to find a suitable replacement. JB Weld is fine for setting them. Two of my 125s got all the plugs replaced and set with JB Weld.

So a "pressed-in" style freeze plug?

 

[Steve]

@heimannm

 

[Lee H]

Mcculloch used those plugs in most all there older saws and kart motors. You should be
able to find them at your auto parts store. They are not a cup style plug but a dished type
expanding plug. You install with dish up and tap the center down to expand it. Similar to
whats in a chainsaw carb.

 

[Scotty Overkill]

Mcculloch used those plugs in most all there older saws and kart motors. You should be
able to find them at your auto parts store. They are not a cup style plug but a dished type
expanding plug. You install with dish up and tap the center down to expand it. Similar to
whats in a chainsaw carb.

Thanks, Lee. I'll check into it.

I've never tore down an old Mac before, this is my first. So I wasn't aware they made their transfers in this manner..

 

[Hinerman]

@heimannm

@awol also

 

[heimannm]

I sent a metering and a fuel pump diaphragm to Joe Salva some time ago hoping to get some part reproduced for the BP-1 carburetor but I haven't heard back. McCulloch used that same carburetor on the 170 Welder.

Mark

 

[Chainsaw Jim]

I sent a metering and a fuel pump diaphragm to Joe Salva some time ago hoping to get some part reproduced for the BP-1 carburetor but I haven't heard back. McCulloch used that same carburetor on the 170 Welder.

Mark

Which carb is supposed to be in the bp-1? All acres says is McCulloch brand. Is that the same flatback primer model as the other saws?

 

[Mastermind]

 

[Sleeper]

Thanks, Lee. I'll check into it.

I've never tore down an old Mac before, this is my first. So I wasn't aware they made their transfers in this manner..

I've got some of those plugs. Well, a box of them. I'll see if I can find them. Meanwhile, you measure the hole. If it's the same as a Super 44A or 790 transfer port hole, these will work. Made several trips to Fastenal to finally get all of these spare plugs. Hoarding them, you see.