075 Questions

[Yellowbeard]

Update:

Service department at my local shop called today so I went in to talk to their best mechanic who used to be an aircraft mechanic. He hadn't worked on this model saw, but pretty quickly determined that the crankshaft seals were likely leaking. He said that best case it would be just the seals, worst case: a groove in the crank shaft.

He's going to replace the seals and check to see if he can see any grooving when he does so (and not replace them if he finds any).

Opinions?

 

[Big Beech]

I would suggest looking in to a proper milling chain, like the granberg as they have two differing types of cutters. a scoring and a clearing (I think). worth the xtra cost in my mind. buy the right kit once and all that :msp_wink:
also, on my 36" sprocket tip bar, I cannot mill larger that 29" absolute max due to the sprocket rivets and exhaust / mill leg clamp. that however may be different on the 075. I use an 054 /064

 

[Yellowbeard]

I would suggest looking in to a proper milling chain, like the granberg as they have two differing types of cutters. a scoring and a clearing (I think). worth the xtra cost in my mind. buy the right kit once and all that :msp_wink:
also, on my 36" sprocket tip bar, I cannot mill larger that 29" absolute max due to the sprocket rivets and exhaust / mill leg clamp. that however may be different on the 075. I use an 054 /064

My thought on milling chain was this (and I would love to hear arguments why I am wrong, which I likely am): The 075 has a serious amount of grunt. I figured that it was worth using that grunt on a full tooth chain. My understanding is that the skips, being for clearing, lessen the burden on the saw, but I had understood from this forum that the cutting burden was not what one should be concerned with in this saw, rather that it was hard to put enough load on it to make it use up all it's power. So I thought I would cut with every tooth.

Thoughts?

 

[flashhole]

The difference is chips (regular chain with a steep cutter angle ~30 - 35 degrees) and coarse sawdust (ripping chain with a shallow cutter angle ~10 degrees). Smoothness of cut is also a factor. You get smoother with a shallow cutter angle. The ability of the saw to pull through the wood is only important in that you don't want to have too little power to do the job and risk burning out the saw.

Others will have to weigh in too.

 

[Yellowbeard]

The difference is chips (regular chain with a steep cutter angle ~30 - 35 degrees) and coarse sawdust (ripping chain with a shallow cutter angle ~10 degrees). Smoothness of cut is also a factor. You get smoother with a shallow cutter angle. The ability of the saw to pull through the wood is only important in that you don't want to have too little power to do the job and risk burning out the saw.

Others will have to weigh in too.

The teeth are cut to 10 degrees. I just don't have any skips in them.

 

[samdweezel05]

50:1 Stihl HP ultra
Skip or no skip made no difference on my mill (sharpen to 10 degrees made a world of difference on both)
Replaced crank seals
41" bar

 

[Yellowbeard]

50:1 Stihl HP ultra
Skip or no skip made no difference on my mill (sharpen to 10 degrees made a world of difference on both)
Replaced crank seals
41" bar

That sure looks a lot like my saw. What's an HP ultra?

 

[samdweezel05]

That sure looks a lot like my saw. What's an HP ultra?

Stihl synthetic oil.

 

[DaltonPaull]

I've had many air leaks on my 075 but never the crank seals. It's been either been loose screws on the carb spacer/manifold or loose cylinder bolts. A few turns of the wrench and I was back in business.

Last week the last 3/4 of an inch of the crankshaft snapped off along with the clutch so I finally had to tear it all the way down and put in new seals. I'm hoping to complete reassembly tonight.

 

[Yellowbeard]

I've had many air leaks on my 075 but never the crank seals. It's been either been loose screws on the carb spacer/manifold or loose cylinder bolts. A few turns of the wrench and I was back in business.

Last week the last 3/4 of an inch of the crankshaft snapped off along with the clutch so I finally had to tear it all the way down and put in new seals. I'm hoping to complete reassembly tonight.

That's the next thing I'll try if the oil seals don't work. Needed new oil pump drive gears as it turns out, so I was glad he got in there anyway. I bought aftermarket ones (because they were $20 as opposed to $70). Anyone had any experience with those?

 

[samdweezel05]

That's the next thing I'll try if the oil seals don't work. Needed new oil pump drive gears as it turns out, so I was glad he got in there anyway. I bought aftermarket ones (because they were $20 as opposed to $70). Anyone had any experience with those?

These saws are really pretty simple to work on even when it comes to crank seals and pump gears. I know not everyone has mechanical ability but I bet if you had taken your time and pulled it apart with pictures and notes you could have done what ever work it needed your self. Crank seals come out with nothing more than a sheetrock screw or two. I do this stuff every day for a living and have been inside motors since I was very young. It might be a scary idea to do it yourself but once you got into it I bet you would find it fun. It's not open heart surgery, it's just a chain saw. If your smart enough to own and mill with an 075AV then you already have 95% of the population in the US beat as far as IQ goes. Go out and find a junk crapsman saw and just take it apart. You will see what I mean.

 

[Yellowbeard]

These saws are really pretty simple to work on even when it comes to crank seals and pump gears. I know not everyone has mechanical ability but I bet if you had taken your time and pulled it apart with pictures and notes you could have done what ever work it needed your self. Crank seals come out with nothing more than a sheetrock screw or two. I do this stuff every day for a living and have been inside motors since I was very young. It might be a scary idea to do it yourself but once you got into it I bet you would find it fun. It's not open heart surgery, it's just a chain saw. If your smart enough to own and mill with an 075AV then you already have 95% of the population in the US beat as far as IQ goes. Go out and find a junk crapsman saw and just take it apart. You will see what I mean.

Thanks for the vote of confidence. I actually seriously considered it. I built a car in high school and am generally pretty mechanically inclined. The problem in this case was that I have been busy working on the house all summer. If I had stopped to work on the chainsaw, my wife may have been fairly upset.

Anyway, now that I've seen someone going through it, I am less intimidated (I have never done much work on 2-strokes, but I guess they are probably quite a bit less complicated than 4-strokes, eh?).

Anyway, in the future I will do just that. I just had tried tuning the carb, following the instructions in the book and was getting nowhere so I thought I'd have someone else look at it this first time.

 

[Yellowbeard]

Update:

I ordered an aftermarket oil pump and worm drive gear for the saw as mine was pretty worn. (This part: OIL Pump Worm Drive Gear Fits Stihl 050 051 075 076 | eBay).

The pitch on the new part is different than that on the old, which I suppose doesn't matter too much as long as it meshes with the other new part that came with it. However, the part that goes over the crank shaft seems too tight. My mechanic is worried that it will spin all the time because of friction with the crank instead of only being driven by the clutch as it's supposed to be.

Has anyone had this problem? Should I just try another part? Should I pay 4X as much for the OEM part?

Thanks!