Makita 6401 - few questions for the experts

[jra1100]

I have a 6401 and it is my favorite saw. I got to run Grampas with either a 79 or BB not sure which at the Iowa GTG. Wow is that a set up, a wood cutting demon. A good part of that is that he can sharpen a chain till it's sharper than a sushi knife, but is a real handful in the cut as when it hits wood it pulls ya right up close and personal to the log. I have always been going to change up to a bigger top end on mine, but just never do it cause it does what I want at 64cc'c. Gramp's has a real runner though. JR

 

[blsnelling]

My testing found that a MM is worth little to nothing on an otherwise stock 7900. It will sound better though and won't hurt anything

 

[ctkelly]

Well last night I removed the muffler, uncrimped it and proceeded to modify it some. I slotted some of the holes in the baffle to make the openings larger, but made sure there was plenty of metal between adjacent holes so the baffle wouldn't crack or burn apart. I also enlarged the port so it was as wide as the deflector. Hopefully today or tomorrow I can add another port/deflector and call it good. I re-crimped the halves together using the anvil of my vice and a punch/ball peen hammer. Put it back on and fired the saw up to see what if any difference has been made. Sounds a little different, but nothing too major. I may have the welding expert at work tig it also to make sure it doesnt leak, but I think I did a good enough job re-crimping that its not leaking anywhere.

If anyone is interested I can post some pictures of the modifications I've made, but I think theres been enough muffler mods done on here that its probably not necessary. :msp_tongue:

 

[jimdad07]

Well last night I removed the muffler, uncrimped it and proceeded to modify it some. I slotted some of the holes in the baffle to make the openings larger, but made sure there was plenty of metal between adjacent holes so the baffle wouldn't crack or burn apart. I also enlarged the port so it was as wide as the deflector. Hopefully today or tomorrow I can add another port/deflector and call it good. I re-crimped the halves together using the anvil of my vice and a punch/ball peen hammer. Put it back on and fired the saw up to see what if any difference has been made. Sounds a little different, but nothing too major. I may have the welding expert at work tig it also to make sure it doesnt leak, but I think I did a good enough job re-crimping that its not leaking anywhere.

If anyone is interested I can post some pictures of the modifications I've made, but I think theres been enough muffler mods done on here that its probably not necessary. :msp_tongue:

Hope you get a little gain out of it, but I bet you don't get much. That saw does have a lot of grunt in stock form, I love mine.

 

[nmurph]

Also, be aware that this saw has a limited coil which makes tuning by ear tricky. Enlarging the exit hole will probably change the carb settings some, so the saw will need to be retuned to keep from damaging the piston/cylinder. You will need to tune it in the wood to do it correctly.
Oh yeah, as mentioned earlier, muffler mods on these saws don't produce much if any additional power.

 

[mtngun]

The muffler exit is restrictive as is the spark screen. Do the calcs, figure out what size exit you need to hit 85% of exhaust port area.

 

[CharlieG]

I run my 6401 stock, and its runs great

 

[gmax]

I couldn't be happier with my 6401BB :msp_smile:

 

[jimdad07]

That's a good looking saw Gmax. I like the way the HD filter looks on that line.

 

[gmax]

That's a good looking saw Gmax. I like the way the HD filter looks on that line.

Thanks, the HD filter is excellent nothing gets past it.

 

[w8ye]

The Makita really looks nice with the black covers from a Dolmar

 

[FATGUY]

well since we're playing show and tell.....

View attachment 190363

I shamelessly submit my girl : )

 

[ctkelly]

What is the part number for the black dolmar cover and how much does one cost? Mine has a rental number engraved into it and i think the black dolmar cover looks nicer, might be a worthwhile "upgrade" if its not too expensive.

 

[ancy]

Can't remember the part # but i think it was around $11 or so. What part of Iowa are you in, I'm near Carroll? Can't really hear the tune difference in wood and set mine to 13,200 RPMs but I think it has more just need someone with a better ear. Love the saw in stock form but it is the biggest I've run so. When you get your tech let me know what you are running for RPMs. Here is my set up.

View attachment 190376

 

[ctkelly]

11 dollars would be worth the cost to me anyways. Im in Fort Dodge. Did a computer install at a bank once in carroll for dell, nice town. When I get mine up and running with a tach and bury it in some wood I'll let you know what I come up with.

 

[Chopper G]

I couldn't be happier with my 6401BB :msp_smile:

Nice pic. I like the black dogs. Is that paint, powder or anodized?

 

[gmax]

Nice pic. I like the black dogs. Is that paint, powder or anodized?

Anodized

 

[ctkelly]

Haven't picked up a tach yet but did get some good advice from matt aka MCW. First off, yeah that felt filter causes the saw to run rich. Took it off and things cleared up right away. I picked up a 28" bar and chain for it, simply because it was on closeout at baileys otherwise I would have stuck with 24". Unfortunately, this made the saw nose heavy....I'm heading out to my friends acreage to try some bigger timber to see how the saw does, if I like the 28" bar enough I might have to look into a reduced weight bar...but I think husqvarna techlite is the only one available in 058 gauge which is what we run? Or I guess I'll have to grow some bigger muscles.

Edge and engine was helpful in tracking me down the black cover and part number for the dolmar hood, got it installed and digging it so far. Lastly, I did pick up the big bore kit from Matt. Depending on how it does at the acreage I may install it right away for wait till this winter...knowing me though I'll want to do it ASAP just to play with it.

Thank you to everyone who posted and helped with this little project.

 

[mtngun]

that felt filter causes the saw to run rich.

My Kita came with a carb that has adjustable jets.

 

[RiverRat2]

---

For as much fun as I initially made of the HD filter cover, I now actually think it significantly improves the looks of the 7900. In stock form, they're about as cool as an AMC Pacer:msp_ohmy: Are you going to try to tell me these are tasteful next?!!!

Yeah if you're a Buffalo Bills Fan!!!!!!!!!!! LOLOLOL!!!

The Makita really looks nice with the black covers from a Dolmar

Hey,,, yeah it does!!!