Dolmar/Makita 6400/6401

[Jayson H]

Hey Everyone,

I bought a second-hand Makita 6401 last week, my first foray into pro-level saws. I also run a MS291 and older MS010AV. My teenage son has graduated from the 010, he is going to use the 291, so I need a saw!

I bought it off a farmer for $50, who tells me it has little use, which seems legit because there is still some paint on the bar. I do my own servicing on the two saws, but this 6401 has me stumped.

When I got it home, I dumped the fuel and oil out of it, put in fresh 2 stroke, cleaned the air filter, and it started after 3 pulls.... you beauty, I thought!

So pulled it apart and gave it a clean, just the usual, chain cover, around clutch, starter housing, air filter cover, etc, gave everything a good blow-out with compressed air.

New spark plug, washed air filter with detergent and water, dried in sun and blew compressed air through it. Put back together, and it doesnt want to start!

No problem, I think - did some research, thought it may be the carby, pulled it apart, cleaned with Carby Clean, put back together. Still no start!

Checked spark, appears ok, re-did coil gap with business card, poured some fuel directly into cylinder. Still not starting. Wont even 'pop'.

I emptied the fuel out, left in the sun all day with no spark plug, and then re-fueled with new (today) 98 octane. No pop.

There appears to be fuel flooding in, when I use the decompression valve, I can see it vaporising out, like a fine mist - should this be happening?

I have ordered a carby kit, because it is cheap, before it arrives, is there anything else I can do?

I am keen to get this saw going, and learn along the way.

Cheers

 

[Hulsty]

They are very easy to flood, tried starting without choke?

 

[Jayson H]

They are very easy to flood, tried starting without choke?

Yep, sure did! I let it dry out overnight, then tried to start it with no choke. Still no Pop... Very frustrating!

 

[ErnieG]

Fuel filter or check compression?

Ernie

 

[Jayson H]

Fuel filter or check compression?

Ernie

I removed the filter, and tried to start it, no 'pop', choke or no choke.

Compression seems ok, I don't have anyway to test it, but, compared to my MS291, it is slightly more difficult to pull, without the decompression button on.

Is it normal for fuel to spray/mist out of the decompression switch? It seems dangerous!

 

[2StrokeFondler]

Is it normal for fuel to spray/mist out of the decompression switch? It seems dangerous!

No, that's not normal. Likely still flooded. I'd remove the spark plug, turn it upside down, pull it over 10 times and leave it like that over night. Next day try to start it on fast idle, if that doesn't work alternate between 3 pulls on full choke, 3 pulls on fast idle.

 

[Jayson H]

No, that's not normal. Likely still flooded. I'd remove the spark plug, turn it upside down, pull it over 10 times and leave it like that over night. Next day try to start it on fast idle, if that doesn't work alternate between 3 pulls on full choke, 3 pulls on fast idle.

Ok, done. What do you mean by 'fast idle'?

 

[heimannm]

Put the choke full on, you should be able to feel or hear a "click" as the choke mechanism also sets the throttle position to "fast idle", push choke off without touching the throttle and it remains in the fast idle position.

I prefer to just hold the throttle wide open and pull them over with the choke off if I suspect a saw is flooded. Sometimes it takes 8-12 pulls to clear them enough to get a pop.

Mark

 

[blades]

Yep easy to flood , pia to clear. Make sure the plug is good, been running into a lot of bad new plugs. also make sure it is the correct type for the saw. I have 2 ea of the 64xx ( one is dressed as a smurf and 79xx series every so often i mess up and flood one.

 

[Jayson H]

Put the choke full on, you should be able to feel or hear a "click" as the choke mechanism also sets the throttle position to "fast idle", push choke off without touching the throttle and it remains in the fast idle position.

I prefer to just hold the throttle wide open and pull them over with the choke off if I suspect a saw is flooded. Sometimes it takes 8-12 pulls to clear them enough to get a pop.

Mark

Ok, thanks, a bit different to my Stihls then.., not quite as obvious. Now that you explain it I get it.

 

[Jayson H]

Yep easy to flood , pia to clear. Make sure the plug is good, been running into a lot of bad new plugs. also make sure it is the correct type for the saw. I have 2 ea of the 64xx ( one is dressed as a smurf and 79xx series every so often i mess up and flood one.

Good call! Plugs are cheap. The spark was bright and blue to me, but never know under compression. I matched the plug that was in it, so will check the manual and buy another today.

 

[Wood Doctor]

It is rather rare that the spark plug is the problem. About one chance in ten for me. Regardless, I always check the spark with a jumper connection to be sure it has one. Unfortunately, the new M-tronic saws do not allow that simple spark check. Yours is not one of those, and that is why I still own my 6401, a saw that is one of my favorites:

That's a 32" bar on board and it pulls it without difficulty. Cheers!

 

[Jayson H]

It is rather rare that the spark plug is the problem. About one chance in ten for me. Regardless, I always check the spark with a jumper connection to be sure it has one. Unfortunately, the new M-tronic saws do not allow that simple spark check. Yours is not one of those, and that is why I still own my 6401, a saw that is one of my favorites:
View attachment 1247609
That's a 32" bar on board and it pulls it without difficulty. Cheers!

Yikes! Thats a big bar! I am soooo keen to see how it goes against my 391. Got no plans to upgrade from the 20 inch bar that's on it now, but it would be tempting in the future, as the 391 has an 18 inch. I am in Australia as well, so $50 is pretty much what I spend on lunch for two, so if I can get a pro level saw up and running for a that, I am going to be a very happy man!

 

[huskihl]

Fuel seeps through the inlet needle and floods the crankcase when they sit occasionally. Remove the needle, cut a Q-tip on an angle and polish the needle seat with some toothpaste. Stretch the spring out a little bit and put it back together and it should be good

 

[Jayson H]

Fuel seeps through the inlet needle and floods the crankcase when they sit occasionally. Remove the needle, cut a Q-tip on an angle and polish the needle seat with some toothpaste. Stretch the spring out a little bit and put it back together and it should be good

OK. I have a new Carby Kit on its way, so will do this when I install.

 

[Jayson H]

It's Aaaallllliiive!! The $50 chainsaw is a goer. Started second pull, no choke, high idle. Really happy about this.... Thanks for a help everyone, will report back over the weekend, after I sharpen the chain and get some cutting done!