Jump to content

OT chainsaw running badly


Recommended Posts

Hi All,

I've got a McCullough chainsaw here that has started acting up.

Runs okish at full throttle but won't idle, or even run below 1/2 throttle. The exhaust note deepens and the revs don't increase. Eventually it dies. Is this it running rich?

We've messed about with the air and fuel filter on the pickup (Hmm, I wonder is there another fuel filter) and the plug gap. Now it won't clear and run to full revs at all. :angry: Fuel mix is pretty close to 40:1

What do you think?

I don't know much about petrol/carbs but does it sound like a dirty carb, weak spark or what?

Stoopid pertrol engine, if it were mine I'd buy a nice diesel chainsaw :ph34r:

LR content, erm, was fiddling about with it in the back of the 110. :ph34r::ph34r:

Link to comment
Share on other sites

McCulloch chainsaws are made in Italy.

Not a very good make I'm afraid, but you can strip and re-build the carbs, but I wouldn't have a clue where to get carb kits from. I have a couple of Husqvarna 266XP saws, which are an excellent make. There are usually three adjustments to make on chainsaw carbs - tickover adjustment, and two mixture screws. You have to juggle low revs idle and tickover screw, and once the saw idles relatively smoothly (for a 2-stroke engine, that is), you then set high speed mixture screw. To do this, you open the throttle wide and slowly turn the screw inwards to decrease mixture, the saw will eventually 'hit the right note' at hiogh revs - you'll recognise it when you hear it. Once the right note is achieved, back off a small amount to play it safe.

Generally speaking - unscrew the 'L' needle 1 1/4 turns, and the 'H' needle 1-turn.

It might be worth replacing the plug - they don't last very long on chainsaws.

Check the 1/2mm gap between the coil pick-up and Generator rotor on the end of the crank.

Les. :)

Link to comment
Share on other sites

Thanks all.

Was thinking about stripping the carb tomorrow and seeing what that gets us.

Anyone know what the plug gap should be?

Les, thanks for the info. is the coil pickup on the pullstart end of the crank? I guess it'll be obvious once I get into it.

Woo Hooo, a weekend of fixing the Da's broken toy instead of my LR. No doubt it'll get jealous!

A diesel saw would work underwater, now THAT would be handy :ph34r: ahem.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy