chain oil limited

[woodworkingboy]

Someone brought me a barely used MS660 with poor oil from the pump, I was told, and was asked to look into it. I figured it was the usual with those, and had already told the owner to expect to pay $80 for a better pump, and was going to ask skwerl for a part number. When I took off the bar to see what was doing, fired it up, I found that there was good oil quantity coming out. It's a long Stihl bar that came with the saw, 34", and the bar oil hole is a tiny little thing, that was off center from the pump opening orifice, so half of the small hole was blocked by the plate that the bar sits against. I don't understand why they put such a small oil hole in the bar?

I drilled it out to twice the original size, put a good chamfer around the inside, and now it's spitting oil like it should be. I've done that with other saws, increased the bar oil hole size for better flow, it really does seem to help.

If anyone has a saw that seems to require more oil, that might be a good place to start. It won't make up for a shatty pump, but oil passage seems considerably less inhibited.

 

[Mr. Sir]

Sounds like a design flaw. Thanks for the heads up.

 

[stehansen]

I'll have to check mine out. It has always been stingy with the oil.

 

[woodworkingboy]

I also noticed that they had these little ridges in the bar groove on both sides of the hole, beneath where the drive links go past. The theory, I assume, being that the oil will pool up around the hole, and reach the drivers as they go by. It seems to me that you also would get crud piling up in there, preventing oil flow. Drilling out the hole would help that too.

If you do drill out the hole, be sure to take a thin file and remove the burrs on the inside of the groove from the drill bit. Make a nice clean passage. The bar steel is hard, but a sharp bit will cut it.

 

[Stumper]

There is a possible exception to the "drill it out and get better flow" theory. Oregon's lubrijet bars have a tapered directional hole that is intended to help pump the oil forward at increased speed to prevent clogging from detritus. They work very well on saws with high output oilers. I don't know how they do with puny pumpers.

 

[SkwerI]

All the bar manufacturers are going to the angled holes now. They work ok most of the time on my Huskys but on the Stihls with wimpy oilers it helps to drill them out.

I picked up a set of DeWalt 'pilot point' drill bits from Home Depot. They have a small tit on the end of the bit to help start the hole. If you use the 3/8" drill bit, the pilot point is the perfect size and depth for drilling out the oil hole. As soon as the pilot point gets through, back it out. I use a 1.5" stiff putty knife to clean out the bar groove and knock off any slag on the inside of the hole.

 

[Al Smith]

I took one of my tuned up souper duper race bars and die grindered a little deep groove right by the hole .It holds a tad bit of oil and seems to help .I don't know if it would work with a stingy oiling Stihl or not . In addition the oil hole is 1/4" .

 

[sotc]

Good idea Jay, thanks

 

[cutitup]

Thanks, Jay I'll check that out. My 270 uses oil like al gore desgined it! I'd really like to up the oil flow on it. Perhaps this is the trick.

 

[woodworkingboy]

uses oil like al gore desgined it!

I had a chance to use the 660 on the pine job the other day. The bar modification made one heck of a difference. The owner was very pleased.

 

[Mesquite]

I have often thought about doing this and in the past two days I have ran across this and a video saying the same thing. I think it's time to open the holes on me bars. I cut alot of dead wood and seems to make my bar oil go awol.

 

[Nutball]

I have found the little angled holes common these days can plug up easier than a large straight hole as a guy I know found out every time he would rip chunks of firewood. I'm not sure how ripping wood would plug the hole on a saw with a pretty strong oil pump, but it seems to.

I've also found that wood type and chain aggressiveness can affect how well the bar is oiled, not that flow is affected, but the oiliness of the bar and chain. Dry abrasive hardwoods like Ash and Hickory can suck the oil up fast. Larger chips from an aggressive chain will more quickly wipe the oil out of the bar groove like jamming a cloth in the groove with a knife and pulling it through. I had an Echo 590 (which oils well) I had ported and was testing in a big Ash log with a very aggressive 20" chain. After each cut, the chain would seize and be very difficult to free without using a saw wrench. Once free it would wet the chain quickly until the next cut. I made sure to run a whole tank of gas through it to see that it did use 1 tank of oil to almost a full tank of gas.

 

[BlackSmith]

99% of what I cut is dead and the only way I can keep the oil hole in the bar open is use the top of the bar or keep the tree/log as far away from the powerhead as possible. Factory hole or bored out, same issue.

 

[Marc-Antoine]

Just an idea to reduce the amount of debris pulled back in the groove by the chain (wiping the oil and clogging the oil hole): The flow of the cooling air should go out inside the clutch carter ,to help pushing down the chips and dust, away from the sprocket. I was tempted to try that with the exhaust at first, stronger flow, but the hight heat is an issue.