Finally picked up a used Makita

[DiscoInferno]

I've been trying to snag one of the rental Makita 6401's at Home Depot for a while, much thanks to member fire_N_ice who checked all the local HD lists for me several times. I had several slip through my fingers, as it were, and some others I found were a little pricey at $300. Finally found one beat up enough, I guess, at $225. It came with the standard 20" bar (used, but decent shape) and a new-looking chain, plus the other guy in the tool rental tossed in a scrench and a second chain, plus a quart of bar oil. The guy started it up fine, sounded about right at WOT (?). Only warning sign is that it made a pretty loud screech when the chain brake was on, both when starting it and when he put it back on to stop the chain after gunning it. I'll have to do some testing but it sure sounded like either the chain brake or clutch was slipping. Anyone want to hazard a guess?

Anyway, Bailey's has a 30" bar on clearance for $35, so it looks like I'll be upgrading my milling setup. Probably get the $99 big bore kit too, as I already have enough midsize saws.

 

[zzr7ky]

That's great! I paid the $300 as I only found the 1 saw and it was like new. I'm really wanting to add the big cyl& pison but haven't yet....

 

[Battenkiller]

Outstanding choice! $400 total investment for an 80cc saw with a 30" bar is a great deal. I wish I had that setup. I have about a dozen huge pine logs about 12' long that are way too big for me to move to my new place. I'd love to take them there as 12/4 planks, though, that I can manage.

 

[smokinj]

I would go ahead and throw a new clutch in why your there! Around 30.00 bucks.

 

[Bigg_Redd]

Opps

 

[TreePointer]

As SmokinJay wrote, it sounds like a clutch problem.

I put the OEM 79cc kit on mine two weeks ago and it went pretty smoothly. There's a decent amount of room to work in there.

One complaint is that the limiter cap on the carb's high jet screw makes it a little difficult to find the slot when tuning. The other is that I like to use a tachometer to start my tuning, but the limited coil made it difficult to find the recommended 13,500 rpm. Regardless, I got it to where I want it and it's running great.

 

[DiscoInferno]

Yeah, I need to run it in some wood and see if it slips and squawks under load. I couldn't tell in the quick in-store demo if the chain was still turning when the brake was applied, which would indicate a different slip point. Assuming it is the clutch: is it going to be the clutch itself, or the clutch drum, or both that might need replacing?

I had the same problem with the limiter coil trying to tach one of my saws, the 359 I think. Gave erratic readings. Plus the idiot limiter caps were set so that I could not reduce the high jet below the max RPMs. How easy is it to remove or trim the caps on the makita?

 

[smokinj]

Yeah, I need to run it in some wood and see if it slips and squawks under load. I couldn't tell in the quick in-store demo if the chain was still turning when the brake was applied, which would indicate a different slip point. Assuming it is the clutch: is it going to be the clutch itself, or the clutch drum, or both that might need replacing?

I had the same problem with the limiter coil trying to tach one of my saws, the 359 I think. Gave erratic readings. Plus the idiot limiter caps were set so that I could not reduce the high jet below the max RPMs. How easy is it to remove or trim the caps on the makita?

Look for blueing on the clutch....Its all one deal on a pro saw should be the 30.00 range.

 

[DiscoInferno]

It's two parts sold separately according to the parts breakout - I can find the clutch assembly online for about $24, and the clutch drum (that the clutch spins inside) for about $13. I'm assuming it's the friction interface between the two that's slipping.

Completely aside - what a racket it is selling chainsaw screws and clips! $2-$4 for a single screw or little retaining clip? I need to go through and loctite my 359, screws I've never touched before were falling out left and right this summer, and I lost at least 1.

 

[smokinj]

It's two parts sold separately according to the parts breakout - I can find the clutch assembly online for about $24, and the clutch drum (that the clutch spins inside) for about $13. I'm assuming it's the friction interface between the two that's slipping.

Completely aside - what a racket it is selling chainsaw screws and clips! $2-$4 for a single screw or little retaining clip? I need to go through and loctite my 359, screws I've never touched before were falling out left and right this summer, and I lost at least 1.

Yep yep..That saw must be different. Stihl is clutch and Assembly all come together. Your clutch drum should be fine, just a new rim sprocket, but your right if the rim come with it replace it all.

(Was confuesed there for a moment) I have not ever needed to replace the drum its self.

 

[TreePointer]

Yeah, I need to run it in some wood and see if it slips and squawks under load. I couldn't tell in the quick in-store demo if the chain was still turning when the brake was applied, which would indicate a different slip point. Assuming it is the clutch: is it going to be the clutch itself, or the clutch drum, or both that might need replacing?

I had the same problem with the limiter coil trying to tach one of my saws, the 359 I think. Gave erratic readings. Plus the idiot limiter caps were set so that I could not reduce the high jet below the max RPMs. How easy is it to remove or trim the caps on the makita?

It's pretty easy if you have a T27 torx driver and exacto knife. I pulled the carb completely out and trimmed the wings off the limiter cap with the exacto knife.

Download Dolmar 6400 repair manual here: (1.63MB PDF) http://www.baileysonline.com/PDF/6400to79001_repairmanual.pdf

 

[smokinj]

Yeah, I need to run it in some wood and see if it slips and squawks under load. I couldn't tell in the quick in-store demo if the chain was still turning when the brake was applied, which would indicate a different slip point. Assuming it is the clutch: is it going to be the clutch itself, or the clutch drum, or both that might need replacing?

I had the same problem with the limiter coil trying to tach one of my saws, the 359 I think. Gave erratic readings. Plus the idiot limiter caps were set so that I could not reduce the high jet below the max RPMs. How easy is it to remove or trim the caps on the makita?

It's pretty easy if you have a T27 torx driver and exacto knife. I pulled the carb completely out and trimmed the wings off the limiter cap with the exacto knife.

Download Dolmar 6400 repair manual here: (1.63MB PDF) http://www.baileysonline.com/PDF/6400to79001_repairmanual.pdf

If you dont want to pull the carb, use a drywall screw takes a couple seconds.

 

[DiscoInferno]

Gave it a quick test run today. Clutch does not seem to slip at full throttle under load, the squealing happens because the idle is very high and is partially engaging the clutch. The idle is erratic - first start it was high enough to keep the chain spinning, then after a couple of minutes the chain stopped. I cut a cookie fine, after which the saw "idled" at about 3/4 throttle. I then hit the off switch to absolutely no effect - the saw was dieseling (rather smoothly, too). Had to choke it off. Tried to start with and without the switch on to confirm that the switch itself does work. So what causes dieseling in a 2-stroke? My dad had a weed whacker that did that but only after running for 1/2 hour or more. I guess the high idle got it pretty hot pretty quick.

 

[TreePointer]

If by "dieseling" you mean "four stroking" or "blubbering," then the saw is running rich. If the saw runs rich out of the cut, but smoothes out while cutting, then that's what is desirable.

See carb adjustment here:
http://www.madsens1.com/saw_carb_tune.htm

Also look at carb adjustment in the 6400/601 manual.

 

[DiscoInferno]

No, I mean it continues to run even when I cut the spark. It's self-firing.

 

[smokinj]

No, I mean it continues to run even when I cut the spark. It's self-firing.

Clean your switch contacts and inspect them to see if its seated correctly.

 

[DiscoInferno]

The switch seems to work fine - I can't start the saw with it off. The interwebs seem to suggest that dieseling like this can be a result of bad/low octane fuel (it's still got HD's gas in it), running super lean, or carbon buildup. Basically it can happen when you have glowing particles or just an overheated cylinder. Guess I've got some things to check and fiddle with. Can't believe HD has been renting out a saw that would run like that, I hate to think what some folks might do when a chainsaw won't shut off. The other customer in the rental shop with me had clearly thrown the chain on his rental saw and brought it back because "the bar was too long for his tree". Yikes.

 

[DiscoInferno]

Solved pretty much all the problems. The idle was set insanely high, simply turn of the idle screw fixed that. But most of the other issues were due to the fact that the spark plug was about halfway screwed out. Glad I didn't run it long that way, but I wonder about the last renter. Once those two things were remedied, no more dieseling or erratic idling. Put it on the tach, was actually running somewhat rich (seems about the only thing HD did right, but it was probably to offset the air leak around the plug), WOT of 12500 RPM. Goosed the H screw up a bit, and we're golden. It does need a new sprocket, it's missing a screw, and the safety chain it came with sucks; but not bad for $225.

 

[TreePointer]

Not bad at all!

I'm glad it was a fairly simple fix.

 

[Danno77]

I need me one of these.