Echo 18" CS420 - Chain keeps popping off and getting burred up...

[davesl708]

I found the paper...

It says it fits Echo 18" CS400, but the two chains from the box are bigger looking than the original Oregon chain.

In the 4 chain pic, top is still brand new, 2nd is Oregon, 3rd is the other one from the 2-pck, the bottom is off my Stihl 18" MS261 18"and it is longer/bigger...

Hmmm... I'm still confused.

David

The package shows a .50 gauge. Is that the size your bar calls for or does the bar need .58? The chain has to match the pitch and gauge of the sprocket and bar.

 

[Barry 1]

That chain is 3/8 low profile (91) (in your first picture)The Echo site shows it should be .325 chain.
Look on the side of your bar and see if it is stamped with the size. The sprocket on the clutch,and the sprocket nose on the bar have to match the chain.
They both have to be either 3/8(.375) or .325 and then you need the right gauge for the bar groove.

 

[MossflowerWoods]

That chain is 3/8 low profile (91) (in your first picture)The Echo site shows it should be .325 chain.
Look on the side of your bar and see if it is stamped with the size. The sprocket on the clutch,and the sprocket nose on the bar have to match the chain.
They both have to be either 3/8(.375) or .325 and then you need the right gauge for the bar groove.

The Oregon was on the saw when I bought it. New in the box, so I hope to heck it is right.

The other two, look bigger but are the correct size according to the bar, and Yes, the bar says 62 links, 0.050", 3/8 Low Profile...

A buddy suggested I'm popping the chain off the tip... This is a much smaller and lighter saw than I am used to and I might be doing something squirrely with it...

This is really frustrating...

David

 

[Egon]

[video]http://www.oregonproducts.com/homeowner/appguidemoreinfo_consumer.htm[/video]

Site should explain the chain/bar nomenclature. Note the different gauges.

Make sure you file the top and bottom of the bar flat and smooth and reverse it every so often when using.

 

[s219]

The CS-400 has always used 3/8" low profile chain, with 0.050" gauge. That is what the drive sprocket is setup for; if you happen to run a different pitch chain, even if matched to a bar and its tip sprocket, it will mess up the drive sprocket and then the saw will throw or mangle chains. So make absolutely sure that any bar/chain you are running is 3/8" pitch low profile 0.050" to ensure it's compatible with the drive sprocket that came with the saw.

If you are running the right bar and chain and the chain keeps popping off, possible causes are:

1) the chain is too loose or too tight
2) the bar has been worn in poorly
3) the tip sprocket is jammed or lacking lubrication
4) the drive sprocket has worn or been damaged and has deep grooves in one or more teeth

Re #1, to start, tension the chain on a *cold* bar/chain combination. Don't snug the chain further when it warms up and slackens a little, as it will then be too tight when things cool down (in excessive cases, this can bend the crankshaft).

Definitely check to see that the tip sprocket turns freely. Clear it out and lube it (there will be little ports that can take oil or grease).

The CS-400 is one of my favorite saws, and has been dead reliable for me. I normally run it with a 16" bar and chain from Bailey's -- they have had a few different brands of bar/chain under off-brand names (ArborMax, Tiger) that are great bargains and hold up well. Oregon stuff is usually OK too, but overpriced for what you get.

Good luck!

 

[CobyRupert]

Could be all the above. A 3/8" will take a big bite, and if your running very low rpms on little brush it will bite, grab and throw instead of cutting.
Is the chain getting oiled?

 

[MossflowerWoods]

Could be all the above. A 3/8" will take a big bite, and if your running very low rpms on little brush it will bite, grab and throw instead of cutting.
Is the chain getting oiled?

Oiler works well. In fact it was a sunny lovely day for cutting and I could see the fine spray of oil every time I rev'd the saw...

Oiling is not the issue.

David

 

[MossflowerWoods]

...If you are running the right bar and chain and the chain keeps popping off, possible causes are:

1) the chain is too loose or too tight
Nope - 2) the bar has been worn in poorly
Nope - 3) the tip sprocket is jammed or lacking lubrication
Nope - 4) the drive sprocket has worn or been damaged and has deep grooves in one or more teeth

Re #1, to start, tension the chain on a *cold* bar/chain combination. Don't snug the chain further when it warms up and slackens a little, as it will then be too tight when things cool down (in excessive cases, this can bend the crankshaft).

Definitely check to see that the tip sprocket turns freely. Clear it out and lube it (there will be little ports that can take oil or grease)...

Craig,

I sent the 2 chains of to get sharpened and de-burred and ran the third for the rest of the day, but less cutting, mostly loading and moving wood. next day I switched to the 261 with no issues...

The bar, drive and tip sprocket are all new so I do not think those are the issues.

I had never considered too tight, and that HAS to be considered. I was guessing too loose and decided to run it tighter than I typically run my Stihl's...

The CS400 is so light with good power it is a dream to run on the small stuff and I love it, but was really getting frustrated with the chain popping off...

I will pay more attention to the tightening next time I run it and see if my results change. My process is pretty close to what you described, but I will pay more attention next time.

Thanks,
David

 

[CobyRupert]

I bought 2 Oregon 18" chains along with the saw when I bought it, and so far they've both popped off more than once, typically when cutting something small even, and they get awful burred up in the process.

The reason I asked about the oiler, is because it seems to me that a tight chain gets loose as it heats up. Yours works, so cross that off the list.

The only time I've ever had chains come off was when cutting something small, like really small (pinkie size or smaller), especially if it's live (flexible) vs brittle, and it's always been a case of too little rpms with a chain that takes a big bite (3/8") (i.e. the chain grabs instead of cutting). Is this when it happens?
Of course this could be in addition to other issues mentioned above (bar wear, sprocket, chain becoming loose, etc. )

 

[MossflowerWoods]

The reason I asked about the oiler, is because it seems to me that a tight chain gets loose as it heats up. Yours works, so cross that off the list.

The only time I've ever had chains come off was when cutting something small, like really small (pinkie size or smaller), especially if it's live (flexible) vs brittle, and it's always been a case of too little rpms with a chain that takes a big bite (3/8") (i.e. the chain grabs instead of cutting). Is this when it happens?
Of course this could be in addition to other issues mentioned above (bar wear, sprocket, chain becoming loose, etc. )

Yes small branches, one smaller than a finger, but revving good, and not green, cut down by loggers in June...

Thanks,
David