7 Pin Rim on Echo CS-310?

[Clarkbug]

Evening everyone.

Have a question for everyone that has just tinkered a little more than me.

A couple years ago I picked up a CS-310 from the dump that had been left for dead. Just needed a little love (carb kit, lines, etc.) and it lived. Someone had run it hard with just waste oil in it and it was filthy. Recoil still doesnt like when its cold...

Anyway, the sprocket is shot on it. I have looked for a replacement, and Echo wants around $40 or so. Oregon doesnt make anything, and I came across some overseas aftermarket setup that comes with a rim sprocket for $13. For the money I am tempted, but its a 7 pin rim that comes on it. Assuming that its not complete garbage, Im a little worried about a 7 pin on a saw this size. It works great as a light limbing saw and is good on fuel for just zipping things off a bigger log or clearing some brush, but its certainly not in the "power to spare" category.

Thoughts? Normally I would just buy OEM, but its 20% of the cost of that saw new, so makes me second guess....

 

[ammoaddict]

So, it has a spur drum now? As long as the outer diameter of the rim is close to the diameter of the spur it should be fine.

 

[Clarkbug]

So, it has a spur drum now? As long as the outer diameter of the rim is close to the diameter of the spur it should be fine.

It is a spur now. I dont know about the diameters as of yet, so would need to buy it and see. Just didnt know if the extra pin was going to be a problem...

 

[heimannm]

In my experience, the 6 tooth spur sprockets are normally 3/9 LP and 7 tooth rim sprockets are full size 3/8 pitch chain. I am not aware of anyone making 6 or 7 tooth 3/8 LP sprockets but I could certainly be wrong about that. Running LP chain on a full size 3/8 sprocket will lead to premature wear of the sprocket and could damage the drive links on the chain.

Mark

 

[ammoaddict]

In my experience, the 6 tooth spur sprockets are normally 3/9 LP and 7 tooth rim sprockets are full size 3/8 pitch chain. I am not aware of anyone making 6 or 7 tooth 3/8 LP sprockets but I could certainly be wrong about that. Running LP chain on a full size 3/8 sprocket will lead to premature wear of the sprocket and could damage the drive links on the chain.

Mark

Good info. I was assuming the aftermarket he was looking at was 3/8LP. Probably need to make sure before he buys it.

 

[Clarkbug]

Excellent points. This is an aftermarket conversion kit, so I am sure that they didnt put much effort into it, and its just a standard 3/8" rim. Dont know if I can even find a 3/8" LP rim that mates up with the drum, since I dont know what spline setup they are using.

Probably just better off getting an OEM replacement spur instead of trying to save a few bucks.

 

[ammoaddict]

Excellent points. This is an aftermarket conversion kit, so I am sure that they didnt put much effort into it, and its just a standard 3/8" rim. Dont know if I can even find a 3/8" LP rim that mates up with the drum, since I dont know what spline setup they are using.

Probably just better off getting an OEM replacement spur instead of trying to save a few bucks.

So nobody makes an aftermarket spur drum like the OEM?

 

[Clarkbug]

So nobody makes an aftermarket spur drum like the OEM?

Not that I have been able to find. I bought a Rotary one off the 'bay, but its for a different Echo 310, so Ill be putting it up here on the swap meet shortly since it wont help me.

 

[Nutball]

I wouldn't use a 7t. The 310 almost shouldn't have gone to market with that little of power, except it could make a good toy for a responsible young man. It needs over 2hp to consider a 7t.