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Makita 6401 oiling very very well, mostly the clutch!

Started by shootingarts, January 16, 2014, 09:59:49 PM

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shootingarts

Pretty much all said in the title, my Makita 6401 seems to get a lot of oil in the clutch cover. Lines seem OK, didn't see any signs of oil around the crankshaft, but regardless of bar oil setting I get lots and lots of oil in the clutch cover.

The slot and hole in the bar do seem to match up fine, I might confirm that with the saw running and chain only off. The good news is with this wet clutch set-up I am holding great RPM in the cut according to my new TTO tach. Can't picture it being a good thing long term though.

Any common causes, thoughts, troubleshooting ideas beyond just taking it apart eyeballing as I go like today?

Thanks for any Assistance!

Hu

deerslayer

How about the bar and chain? Does it seem to be getting the normal amount of oil? And what about oil consumption? Has it changed?
Too many chainsaws, not enough wood.
Stihl, Husky, Craftsman, Mac, Homelite, Poulan. Some live here, some just passing through.

deerslayer

Did you change anything on the saw? ie, different bar, chain, drive sprocket? And the oil is getting in the clutch drum as opposed to on the clutch drum?
Too many chainsaws, not enough wood.
Stihl, Husky, Craftsman, Mac, Homelite, Poulan. Some live here, some just passing through.

shootingarts

The bar is the original Makita bar. I have cleaned it a handful of times and verified the holes and rails are clean.

At the moment I have chain oil turned all the way down and have to say the chain is only getting lightly oiled on a twenty inch bar, will open it back up some. When I bought the saw used with very low hours the oil adjustment was set to max. I lowered it a little, then a little more. I finally turned it all the way to minimum to try to see the effect on the oil in the clutch cover. Seems like it helped, can't swear to it since I only made a couple of test cuts tuning the carburetor. A side note, the carb was set very rich on the high side with the limiter cap in place, apparently the break-in tune.

There has been significant amounts of oil getting in the clutch cover since I had the saw. I have used the saw maybe six to ten hours max so honest run time may be two hours or less. Hard to have any firm opinions about changes in that short of a time, I don't know.

I cut the rakers down on the factory chain just counting strokes and it is my rough work chain. I run a Stihl RSC as my good chain and have a spare for it. The issue seems unchanged with factory or Stihl chain.

No history with the saw when I got it. The gas in the tank was fresh enough it popped off and ran a minute before I dumped it and put in fresh gas. The bar oil seemed dry and I suspect that it may have never had bar oil in it. There was a small spot missing paint on the bar, maybe two inch by three inch without being able to measure at the moment, and the original chain had never been sharpened.

The oil is getting all inside the clutch housing and both outside and inside the clutch drum. Looking at the amount of oil on the inside it appears that the oil is coming from the edges in rather than leaking around the crankshaft. Obvious burning between the clutch shoes and drum, very little oil further in than that. I had expected a loose or damaged hose or a leak around the crank. Doesn't seem to be the source, now I'm lost.

Hu

Andyshine77

Are you running the saw out of the wood alot? Oil will sling all over the clutch cover when you do that. If you had an oiling issue the chain would also bind. It really sounds like you have no issues at all. Turn the oiler all the way up and leave it, the more oil you have on the chain the better.

Your saw also has a revlimiter which can make the saw sound rich when it's actually lean. Unless you know what you're doing turn the high speed screw back out until it stops.

Andre.

shootingarts

Quote from: Andyshine77 on January 17, 2014, 04:32:37 AM
Are you running the saw out of the wood alot? Oil will sling all over the clutch cover when you do that. If you had an oiling issue the chain would also bind. It really sounds like you have no issues at all. Turn the oiler all the way up and leave it, the more oil you have on the chain the better.

Your saw also has a revlimiter which can make the saw sound rich when it's actually lean. Unless you know what you're doing turn the high speed screw back out until it stops.



Andre,

While I haven't been running the saw out the wood a lot, the saw has been limbing and cutting four to six inch diameter fence row stuff a lot just to run it regularly. Perhaps that is the story. The chain was getting lightly oiled when I cut a couple of cookies and did some noodling playing with my TTO tach that just arrived a couple days ago after restricting oil pretty heavily with the pump adjustment. Just seems like I am getting more oil in the clutch area than ever goes around the bar.

I just neutered the limiter cap on the high side, none on the low side from the factory, or not when I got the saw. It was running very fat with the limiter cap in place, had to be break-in setting and even then it seemed ridiculous, around four full turns out. Minimum open with the limiter cap in place would have been three turns or close to it. Max RPM under 11K by the tach before dehorning the limiter cap, factory rated at 13.5K max.

The Dolmar 6400 repair manual I was able to download indicates one turn out on the low speed screw, one and an eighth out on the high speed screw. That was before I advanced the timing and upped the compression a little by removing the gasket and cleaning up the mating surface of the cylinder a little. Added 4-6 degrees to the advance, maybe a little more. No idea what I did to the compression but there did seem to be a noticeable change pulling the starter. Can't safely crank the saw until this afternoon to let the sealer set up, I'll check for air leaks then.

No idea where the mix screws will need to be adjusted to but I assume both out a quarter to three-quarter turn from factory, maybe more. Right now the saw will turn about 12500 max according to the tach when it is four cycling when I lift a little in the cut. Doesn't seem to four cycle if I try to lean it more than that. I am opening the high speed screw until the free rpm falls off several thousand and then closing it about an eighth turn at a time until I get four stroking when I lift the saw a little in about twenty inch seasoned oak, ripping, running clean when cutting.

I should have better access to some test wood this evening, not much on hand after the rains a few days ago. I planned to lower and flatten a tall piece of almost 20" diameter log I use for a noodling block to give it to my brother for a splitting block. That along with a few pieces of month old gum only about 10" diameter almost twenty inches long that I needed to noodle anyway was my only test wood. Ripping and a couple cookies from the oak block and noodling the gum was my only test wood I had available. Dryer now after some rains and there is a big oak log in the pasture I can completely bury the bar in or shape a little to make a cut in about eighteen inch wood cutting cookies with the twenty inch bar. I have went to premium nonethanol gas and BelRay H1-R mixed square on 40-1 so fuel and oil should be nonissues tuning the carb.

It is a possibility that this is normal oiling and I just needed to turn it down in the small stuff. That was what I thought at first but it just seems like I am getting more oil in the clutch cover than the bar ever sees. Very little spatter with the pump adjustment turned all the way low but the chain is lightly oily. Still seems to be lots of fresh oil in the clutch cover. I did thoroughly clean the clutch area with brushes and carburetor cleaner while I was working yesterday so I should be able to see what is going on better for a little while. The clutch is obviously slipping sometimes now though. It will cut slowly for awhile then hook up and glide through the wood. Nice saw when it is working right pulling the Stihl full comp chisel chain, round ground, on a twenty inch bar.

Sorry to write a book but I'm trying to put all information on the table, tough troubleshooting long distance!

Hu

sweetjetskier

This a common problem with this saw.

The oil lines have been updated a few years ago from black to green lines.

I had a 6401 and did the swap out and had no more Exxon Valdes type oil problems.

Parts are cheap, pretty easy fix.
Arborist, Horticulturist, Nursery and Turfgrass Professional with 27 years experience.

shootingarts

Quote from: sweetjetskier on January 17, 2014, 03:15:24 PM
This a common problem with this saw.

The oil lines have been updated a few years ago from black to green lines.

I had a 6401 and did the swap out and had no more Exxon Valdes type oil problems.

Parts are cheap, pretty easy fix.

Cool Beans! Having just been playing with them I know the lines are black. Time to go in search of green lines although I'm always suspicious of anything supposed to be green.

Thanks a bunch, gonna give this a shot.

Hu

Andyshine77

Correct the green lines are the updated lines and don't seem to leak. The main issue is the pressure fit between the pump output hole on the pump and the oil feed line that goes to the bar. Part number 038 245 061. I normally replace the lines that come from the oil tank while I'm at it. Part number 038 245 020.

HU the saw shouldn't even run with the high speed screw turned out that far, should be 1 to 2 turns out max, from lightly seated. The 6400's have tight squish from the factory, the last one I checked had .018" of clearance with a gasket, so you have to check clearance before you fire it up. 
Andre.

shootingarts

Andre,

First many thanks for the part numbers, gonna get on that just shortly. No dealer around here, any thoughts where to order online? I can dig for myself but haven't yet.

The carb was weird when I started messing with it, I could close the low speed screw and the engine still run, almost as fast as with it open except it was rougher idling. I wouldn't have thought the saw would run with the high speed jet that far open either and certainly wouldn't expect anyone to set it there even for a rich setting. Limiter cap firmly in place though so somebody somewhere did set it like that. Comparatively big hole in the throttle plate by my eyeball, didn't measure it. I don't know if that is part of the deal or not. Anyway, doesn't matter, the engine side is good now.

I just tuned the saw carb and tested. Saw is idling fair, a little lope at 2600 warmed up. The free RPM is peaking right around 13,000 to 13,200 now, going either way on the high speed screw from a sweet spot slows down the saw. I approached that sweet spot from both sides then set the high speed screw an eighth turn richer. RPM and power both good in the cut, four cycles when I lift. Not much difference in sound but definitely a little duller lower pitch. Wearing earmuffs today so that made it a little tougher to tell, usually don't tuning, trying to start though. A gate I'm closing after the cows are long gone, my hearing has been somewhat impaired for decades and someone who is with me a lot commented they have noticed my hearing getting much worse in the last few years. One good thing about the internet, I hear better in writing! Easier to pass the driver's license eye test on the net too come to think about it.

With the clutch drum and clutches clean the saw flung noodles mighty fine in a handful of test cuts in gum, didn't make it out back to the log in the pasture. I'm happy with the tune now. I'll run it awhile and check the plug, probably buy one or two new plugs just for back-up and it will be easier to read tune on a newer plug. The plug was black before I cut the limiter cap tabs off, starting to turn brown now.

The chain is adequately oiled but just barely at the lowest setting. Not getting hot, a little glisten and running a hand on it, it feels oily. That does reduce oil in the clutch cover some I believe but I'm going to open up the oil pump a little, rather clean a mess and the clutch drum than burn a bar and chain when I get in tougher wood.

Pending further review after I change oil lines I think the saw is good to go. As long as I can keep the oil out the clutch drum it runs fine now.

Thanks to everyone! I do read every post and think about what everyone has to say. I'm having so much fun with the saws that I'm not in the mood to turn wood on my lathe and that is the primary thing the chainsaws are supposed to support. I cut turning wood with them aside from problem trees and routine maintenance on the farm.

Hu

Holmes

You could try Chainsawr a sponsor  They seem to have good pricing.
Think like a farmer.

shootingarts

Quote from: Holmes on January 18, 2014, 12:07:01 PM
You could try Chainsawr a sponsor  They seem to have good pricing.

Thanks, I'll take a look. I do like to try to use sponsors and tell them why I came to them. When sponsors get little or no feedback they start thinking the sponsorships are worthless as advertising dollars spent.

Hu

NCFarmboy

Here is a repair manual for 6400-7900 for you.
Shep
Lots & Lots of Saws

shootingarts

Quote from: NCFarmboy on January 20, 2014, 11:34:57 AM
Here is a repair manual for 6400-7900 for you.
Shep



Thank You!

Might be the same one I have but I added a letter and downloaded this manual. Might be a newer version.

Hu

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