How to fit a replacement chainsaw bar

Published

Replace your chainsaw's bar if it's warped, if the groove is damaged, or if the nose sprocket doesn't turn freely. Watch Matt demonstrate on a McCulloch Mac 335.

Video Transcript:

Hi, I'm Matt from eSpares.

And in this video I'm going to show you how to change the bar on a chainsaw.

Now I've got a McCulloch Mac 335 here - it's quite a popular model, but the process should be pretty similar for all chainsaws of this size.

Now whenever you are replacing the chain on a chainsaw it's a good idea to flip the bar over, and that will just help it to wear just a little more evenly. But every two or three changes of chain, you really should be replacing the bar. Or, of course, if it's warped or bent, or if the groove is damaged, or indeed, if the nose sprocket isn't turning freely. 

Now, obviously, make sure you get the right bar for your make and model. This is a 14 inch or 35cm bar as measured from the base to the nose, and that's what I've got here for my replacement. Now whilst I'm at it I'm also going to put on a new chain as well.

Now just a few words about safety. It is a chainsaw, it is very dangerous. When it's in use we do need to make sure we've got proper protective equipment. That means protection for our ears, for our eyes, some decent gloves, and ideally some proper protective trousers or chaps.

Even when it's not in use, we still need to treat it with respect. Always make sure you keep the blade pointing away from you, that the kill switch is in the off position, and if we're not using it for any period of time, then keep the scabbard or the chain guard on. 

Now when it comes to maintenance or repair we need to be especially careful. Don't do any work on it after it's just been on, because it will be hot and very easy to burn yourself. To be extra careful, I'm actually going to remove the cylinder shield here, and disconnect the spark plug, so there is absolutely no way that this can start accidentally. Okay so that's the cylinder shield out of the way, and then disconnect the spark plug.

Now if you are unsure about anything, don't take any chances, do consult with a qualified repairer. 

Now I've removed the scabbard and I just need to undo these two nuts which are holding on the clutch cover. I'm just using a 13mm socket. So with that last nut off, the clutch cover should just come away. If I push the bar in then I can just lift the chain off, all the way round, slide the bar off, and the chain comes away as well. Okay so whilst we've got the clutch cover off and the bar out of the way, it's a good idea to get in there and give it a good old clean. Get all that rubbish out of there with an old cloth. And also on the chain break make sure that's all nice and clean and clear and there's no damage to the chain break itself. 

Okay so now that's all nice and clean let's get the new bar in place. And make sure we've got our chain the right way round. Yep, that's good. We want to have the blade links, the sharp edge of the blade pointing in the direction of travel, which is that way along the top of the bar. And then hook it over the sprocket, and then just make sure that we feed these drive links into the groove on the bar. There we go, that's all looking good.

So it's time to put the clutch cover back on - just making sure this adjustment pin is in the right place for the hole in the bar. There we go, that's on. And then just loosely put the nuts on so that that holds the cover in place. So with everything in place I just need to adjust the bar to put the chain under the correct tension. You should hopefully see that just tightening the chain up. 

So how tight does the chain need to be? Well if we look at the bottom here, what we're looking for are the cutter links, and these ones in-between, the tie-straps. They should just be nicely touching the bottom of the bar, and if I pull that down, it should just pop back up into place. And when it's like that, I'm just going to give it another quarter turn and then I can tighten up the nuts on the clutch cover really tight.

Now the final thing is lubrication. It's really important when we've replaced the chain and the bar to make sure that everything is properly lubricated. You should have a lubrication oil reservoir - this one is completely empty. And I'm going to fill that up with proper chain oil, and I'm also going to get some oil onto the chain itself and importantly into the sprocket here at the end. You can see there is a tiny hole there - if you've got an oil can it will be easier to get it in there, but I'm just going to pour a drop on. Let that go into the hole and then use a cloth to get that and rub all over our chain. Get plenty of oil on there, get really lubricated well, so that's going to turn nice and easily. 

So spark plug back on, and the cover back in place. So there we go, a new bar fitted. Bars and chains are available for all makes and models of chainsaw on the eSpares website.

Thanks for watching.