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McCulloch Mini and Small CC Chainsaw's

Manic84

Manic84

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I'm back with yet another stupid question, I'm curious about the manual oiler on these mini macs.
I got a problem with one I'm currently working on with it sticking, it had that problem since it showed up, but lately it's gotten worse.

The rod seems to bind somewhere in the pump body itself but I can't figure out where, the return spring looks good and there's no wear/binding marks on the rod or the inside of the pump at all... so what am I overlooking?
 
heimannm

heimannm

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upload_2020-2-16_14-15-21.png

The pump body (item 28 above) is nothing more than a plastic tube with a cylinder of screen, if it is binding you probably need to replace the pump body as it most likely as a kink in it somewhere. They can be tricky to remove and even more challenging to install correctly. The old McCulloch documents suggested using the oiler rod from a large frame saw to push it down into position, the oiler rod has just the right bends in it so as to locate the pump body in the correct position to pop into place.

Mark
 
Manic84

Manic84

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Thanks heimannm.

I'll see if I can't track down a replacement, but before I replace it, I had something come to mind that I want to try.

I'll see if it works and give an update if it does.
 
Manic84

Manic84

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Update: This is going to take longer than I expected...

The manual oiler, isn't binding anymore after the "fix" I did to it, and seems to work as it should. (I'll give a very detailed explanation later)

But... The tension spring for the throttle latch launched itself into... another dimension apparently.
And after a week of looking for it, I've concluded that I've lost it (the spring and my sanity).

In yet another moment of "inspired" workbench zeal, I made one out of a pen spring and it works... not very well, but it works.

I'd like to replace it, but the spring itself has no P/N and doesn't seem individually available, just the whole throttle latch assembly (93437). So, does anyone know where to find just the spring or would I have to get the whole assembly?
 
Manic84

Manic84

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Thank you, but I'm so sorry, I should have been more clear when I said "Throttle latch" meaning the idle speed/throttle latch spring on the carburetor, not the trigger spring. I put the the P/N in the post, but this is what I'm looking for, Number 32.

Mc110spring.png

Mc110carbpn.png

I'm trying to find the spring itself, and avoid ending up with the whole assembly, and was asking if that's even possible.

I don't want to seem rude or ungrateful, so once again I'm sorry.
 
Manic84

Manic84

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Here is what I did to repair the manual oil pump, I didn't take any pics of the process, but can probably explain it well enough.

After pulling the tank and disassembling the rod, the only thing left was the pump body. @heimannm wasn't kidding when he said it was tricky to get out and back in, but it's easy to get the hang of, once done a few times. (which you may have to do)

After inspecting and cleaning the oiler rod, return spring and pump body, I could find no sign of any binding but could still see/feel it when using the manual oiler. Thank you Mark for pointing out to my stupid-ass the possibility of a kink somewhere in the pump itself.

After reading that and thinking on it, I figured the the best thing was to smooth out any anomaly in the pump body, so I used sandpaper and the oiler rod as a kind of cylinder hone to knock-down any binding points and smooth the walls of the pump body.

This is what I used: Penetrating oil as a lube (liquid wrench), the oiler rod as a hone, a toothpick and some very fine sandpaper (2000 Grit). After cutting small strips of the 2000 grit to size, I wrapped a strip on the end of the oiler rod, sprayed some lube on the pump and rod, then started twisting/turning downwards slowly until reaching the bottom of the pump body. However, the paper would ride up and couldn't reach the very bottom of the pump body. (where the most friction was felt) So I rolled a piece of sandpaper and put it inside the pump body using a toothpick, then the rod to push it down to the bottom than repeated the downwards turning/twisting motion.

I would frequently stop to reassemble the oiler assembly on the bench to check the fit of the rod until very little binding was felt in the pump, making sure it isn't loose in the pump body and if there was any minimal binding, the return spring would be able to overcome it now. After a final cleaning of the pump and reassembly, it's oiling properly, the rod is not loose in the body, it actuates smoothly and does not stick or bind any more. The whole thing only took 20-30 minutes, as compared to waiting 4-7 days on a replacement pump. I expect the "repair" to last for a long time, especially with bar oil keeping it lubricated.

While this worked for my problem, it might not work for yours.
But what do you have to lose? You can't break broken after all.

M
 
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