difference in 3/8 and .404????

[stewie]

can someone spell out the difference please as i cant get any clear answers on the net

 

first off i found this saw in a scrapyard, i think its an 075??? can anyone say for sure???

 

 

and ive been given a 36in rollamatic bar that i was told will fit, but on reading about it ive found that the saw is .404 and the bar is 3/8s, so will it be no good for the saw??? sorry if its a daft question but im only used to little saws and they all come with a bar attached

[agg221]

OK, several questions there.

 

Firstly, can you post a picture of the saw from the top, and another from the fuel tank side - that will help identify which model it is (may need more but I suspect not). Oh, and also one pointing inside the back handle to show where the spark plug and decompression valve are placed.

 

Secondly, the numbers 3/8" and .404" refer to the pitch (distance) between the drive links - these are the bits on the chain that stick down and engage with the drive sprocket on the saw, and the sprocket on the roller-nose end of the bar.

 

They have to match, so you need to change either the one on the bar or the one on the clutch (or get a different bar). Worth having a look at how worn they both are before deciding which to change.

 

If it's not an 075 then you may want a shorter bar anyway.

 

Alec

 

Alec

[stewie]

thanks for that alec, it all makes sense now unfortunatly thats the only photo i have at present, but ill try to get soom more ASAP

[agg221]

I'll have a go at describing the differences between the possible models:

 

075/076 normally have a manual oiler button, near the front under the chain brake (can't see one in your picture).

076 has a square shaped case around the starter handle - 075 is more lozenge shaped.

051 can have either shape of case and doesn't normally have the oiler.

051 has a different placement of the plug and decomp valve to the 075/076 (and the pot is held down with socket head cap screws whereas the 075/076 both use long studs.

041 has only one 'switch' on the top (orange) case bit.

It's not an 050 if the top case is original, as the model number was cast in. The surround also looks too 'orange' rather than the old 'red' Stihl colour.

 

Alec

[stewie]

well there is defo no oiler button and there is no chain brake if that helps mate???

[stewie]

looking up the 051 im thinking it might be that one!!

[Al Smith]

It's a simple matter of either changing the rim sprocket or spur drum that be the case to make it run 3/8" .Drives are cheaper than bars and 3/8 is cheaper than .404 .

[agg221]

To be definite it needs the check on how the pot is held on and the layout of the plug and decomp valve (if fitted).

 

If it turns out to be an 051 they're good with 3/8". It's a slogger not a racer but will cut all day and they're pretty good for milling on stuff up to 2ft. The 051/36" Alaskan/36" x3/8" bar and chain works quite well.

 

Alec

[ben lightfoot]

Useful info, my 051 is running .404 so best check the sprocket (not had it long)

[18 stoner]

I'd say if it has the 404 sprocket on now, it must be a beefy model, so as Al says swap the drive sprocket to 3/8 and it should be dandy.