Makita 6421/7900 Runs Out Of Chain Adjustment

[David _4]

The above saw with a 28" Oregon Power Match 93 DL bar (280RNDD009) and Oregon 72APX 93 DL skip chain, but I have run out of adjustment with life left in the chain. I'm running a 7 tooth rim sprocket and I did verify the chain DL count. I usually run a 20" or 24" bar for firewood, but this summer I have been exclusively running a 28" due to bigger logs. This chain was new and the only chain I have run since the bar was new, any ideas?

 

[dgb84]

It’s almost gotta be a worn sprocket or stretched chain. What does the sprocket look like ?

 

[jacob j.]

You probably just need to take a link out of the chain. A 93-driver chain is standard for a 28" bar on modern Husqvarnas, but I believe the 6401/7901 chassis
is just a bit shorter than the equivalent Husqvarna chassis' (365/372/385/390). When I was cutting with a 7900, I ran a 92 driver chain on a 28" bar and a
104 driver chain on a 32" bar (both Sugi-Hara bars).

 

[David _4]

The sprocket has plenty of life left in it. I would think that would be a lot of chain stretch
.

 

[166]

Just shorten the chain by one driver like Jacob said.

I set them up new with 92 driver chains.

 

[dgb84]

I’d surely trust ole Jacob J. He’s a pretty fart smeller. What I was thinking is that if your chain was a little sloppy and your sprocket was badly worn, it might not snug up enough.

I usually don’t know what the hell im talking about, so we will just add this to my file.

 

[Lightning Performance]

My Makita saws will barely tighten a 93 dl with seven pin on a Total 28" D009 mount. Eight or nine pin is perfect as these fine gentleman stated above.

 

[David _4]

Thanks for the replies. I'll shorten the 93DL chains I have and buy 92DL's in the future.

 

[Wood Doctor]

I like running a 92 DL chain loop on my 28" Stihl bar that I outfitted for my Makita. Same number of cutters on both sides (23) and no skips. My Echo CS-670 can also use the same loop with the same bar.

 

[OldJack]

A new bar will wear in and give you some extra slack too.

 

[dahmer]

I’m running a d009 Mount Husky bar with 93 dL on my 7900 and no problems. May be in the bar design.

 

[Hulsty]

As others above, I run 92DL on mine with 8pin, works well plenty of adjustment.