Stihl 066 32" Bar Lean Seize Failure - Advice

[BR Wood]

I just found out that it sounds like my Stihl 066 had a Lean Seizure. I had the coil replaced by a guy that didn't know that it was out but was a "Small Engine Repair" person. After he couldn't get the saw to start I started taking pics and on another Stihl forum I was told that this pic explained the issue, but maybe not the cause. So I guess the next step is to find out if it is worth repairing. I certainly don't have the money to buy a new one at this time, but I don't want to pay more than the saw is worth to have it repaired or try to do it myself. I am pretty decent on most things mechanical and can follow instructions I am tempted to try to save some money and do it myself. Adjusting the carb or finding out the cause of the failure is the problem I am not sure how to start on. If I had someone that could help me through the process that I trusted local I would rather do it myself and learn from it. However, if I take it to anyone because of my last experience with a "small engine repair" place I will more than likely take it back to the dealer for repair.

I bought the saw used and spent $400 on it about a year ago. Since then I have replaced the choke housing and assembly due to it sticking ($130), replaced the spark plug and air filter($60) and now the coil ($120). All said I have maybe cut with the saw a total of 10 hours. I am a wood worker and use the saw primarily for slabbing trees with an Alaskan Chainsaw Mill and not really much else.

From what I have seen online (Bailey's) a replacement head and piston are $119-149 for aftermarket replacements to $450 for an OEM Replacement. Also seen big bore kits as well and not sure if I am going to replace these parts if that is a better way to go.

What are your thoughts and advice?

 

[hseII]

I just found out that it sounds like my Stihl 066 had a Lean Seizure. I had the coil replaced by a guy that didn't know that it was out but was a "Small Engine Repair" person. After he couldn't get the saw to start I started taking pics and on another Stihl forum I was told that this pic explained the issue, but maybe not the cause. So I guess the next step is to find out if it is worth repairing. I certainly don't have the money to buy a new one at this time, but I don't want to pay more than the saw is worth to have it repaired or try to do it myself. I am pretty decent on most things mechanical and can follow instructions I am tempted to try to save some money and do it myself. Adjusting the carb or finding out the cause of the failure is the problem I am not sure how to start on. If I had someone that could help me through the process that I trusted local I would rather do it myself and learn from it. However, if I take it to anyone because of my last experience with a "small engine repair" place I will more than likely take it back to the dealer for repair.

I bought the saw used and spent $400 on it about a year ago. Since then I have replaced the choke housing and assembly due to it sticking ($130), replaced the spark plug and air filter($60) and now the coil ($120). All said I have maybe cut with the saw a total of 10 hours. I am a wood worker and use the saw primarily for slabbing trees with an Alaskan Chainsaw Mill and not really much else.

From what I have seen online (Bailey's) a replacement head and piston are $119-149 for aftermarket replacements to $450 for an OEM Replacement. Also seen big bore kits as well and not sure if I am going to replace these parts if that is a better way to go.

What are your thoughts and advice?

I would find someone who knows what they are doing & have them to a pressure & vacuum test to rule out air leaks before I put another dime in it.

Just to rule out another possible issue, tell us about you mix & mix practices.

 

[BR Wood]

I use the Stihl mix with Leaded Gas mixed per specs. I am kinda anal about making sure that is right. I only ran the saw for about an hour when it got hot and quit, with only a tank and a half of fuel. I had just got the saw back from the dealer replacing my choke casing, switch and choke assembly. I suspect that after that was replaced they did not adjust the carb. The old choke was original and I don't remember it having two choke positions as the one they replaced it with now does have two.

 

[hseII]

I use the Stihl mix with Leaded Gas mixed per specs. I am kinda anal about making sure that is right. I only ran the saw for about an hour when it got hot and quit, with only a tank and a half of fuel. I had just got the saw back from the dealer replacing my choke casing, switch and choke assembly. I suspect that after that was replaced they did not adjust the carb. The old choke was original and I don't remember it having two choke positions as the one they replaced it with now does have two.

Leaded?

What specs?

50:1?

In a Milling Saw?

It had both choke positions? Just maybe not the paint on the plastic.

 

[Cease232]

They replaced your carb housing but what about the boot and impulse?


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[Ryan'smilling]

I use the Stihl mix with Leaded Gas mixed per specs. I am kinda anal about making sure that is right. I only ran the saw for about an hour when it got hot and quit, with only a tank and a half of fuel. I had just got the saw back from the dealer replacing my choke casing, switch and choke assembly. I suspect that after that was replaced they did not adjust the carb. The old choke was original and I don't remember it having two choke positions as the one they replaced it with now does have two.

Regardless of whether they tuned the saw or not, if you're milling with it, it's pretty important that you verify that the tune is rich enough every time you make a cut. Even if they had tuned it, they would have set it at a more regular H jet setting, something like 13-13,500. For milling I think you would want to be considerably richer than that.

 

[Evan]

You will have to learn to maintain your owns saws or you wont be able to afford to cut wood
It is a must same as learning the alaska mill.

These things are very simple machines thousands of youtube videos to run you through service and repairs.

If you were close id be glad to help and most likely we could revive that saw for very little money spent

 

[rupedoggy]

Check your personal message. Mike

 

[BR Wood]

You will have to learn to maintain your owns saws or you wont be able to afford to cut wood
It is a must same as learning the alaska mill.

These things are very simple machines thousands of youtube videos to run you through service and repairs.

If you were close id be glad to help and most likely we could revive that saw for very little money spent

I have to say Evan that I am learning that the hard way. I am a wood worker and the idea of cutting my own lumber seemed much easier than it has been. I will say that I do enjoy it because I get to decide the cuts of wood that I want from a tree especially if I already have a purpose in mind. So yes Evan I do need to understand how to work on and maintain my own equipment and that is one reason I have joined this forum. I know a majority of the members here can give me the advice needed to do this myself and help me learn what I am doing along the way.

So I have been asked a couple of times about my mix, I threw away the bottle but Stihl only sold one type of 2 cycle oil in my shop.

https://www.stihlusa.com/products/oils--lubricants-and-fuels/oils-and-lubricants/oilhpultra/

Outside of that I followed the instructions of one bottle to 5 gal of fuel (which I was instructed to use non ethanol fuel).

I will look through the topics to see if I can find a thread to help me rebuild my saw but if there is anyone that has the time to help me through PM as I do it for questions and pointers I would certainly appreciate the help. I have actually thought about buying the pressure/vacuum test equipment myself to do the check before starting as if I am to learn I have a feeling this equipment might come in use again later down the line.

I appreciate all of the advice and comments as they all have really helped me to decide to rebuild this saw and do it right. Any opinions on the advantages of just going with the big bore kit from Bailey's?

http://www.baileysonline.com/Chains...6mm-for-Stihl-066-MS-650-MS-660-Chainsaws.axd

Would I have to just get my cylinder bored out to do this and would there be any advantage to that? Or do I need to do more research into how damage my cylinder is first? The kit looks like it comes with the cylinder and all...

 

[Deleted member 149229]

You can’t bore the cylinder, they’re plated.

 

[Cease232]

As Ryan said the most important thing you need to learn is what the saw should sound like and how to tune the carb. I'm constantly checking the tune while I'm milling. You can either tune it so rich that it's a dog and milling is slow and painful or learn to adjust the tune so you get the most outta your saw without burning it up every time. Also most people do not use 50:1 mix when milling. Use a heavier mix for extra lubrication.


Sent from my iPhone using Tapatalk Pro

 

[Mad Professor]

I just found out that it sounds like my Stihl 066 had a Lean Seizure. I had the coil replaced by a guy that didn't know that it was out but was a "Small Engine Repair" person. After he couldn't get the saw to start I started taking pics and on another Stihl forum I was told that this pic explained the issue, but maybe not the cause. So I guess the next step is to find out if it is worth repairing. I certainly don't have the money to buy a new one at this time, but I don't want to pay more than the saw is worth to have it repaired or try to do it myself. I am pretty decent on most things mechanical and can follow instructions I am tempted to try to save some money and do it myself. Adjusting the carb or finding out the cause of the failure is the problem I am not sure how to start on. If I had someone that could help me through the process that I trusted local I would rather do it myself and learn from it. However, if I take it to anyone because of my last experience with a "small engine repair" place I will more than likely take it back to the dealer for repair.

I bought the saw used and spent $400 on it about a year ago. Since then I have replaced the choke housing and assembly due to it sticking ($130), replaced the spark plug and air filter($60) and now the coil ($120). All said I have maybe cut with the saw a total of 10 hours. I am a wood worker and use the saw primarily for slabbing trees with an Alaskan Chainsaw Mill and not really much else.

From what I have seen online (Bailey's) a replacement head and piston are $119-149 for aftermarket replacements to $450 for an OEM Replacement. Also seen big bore kits as well and not sure if I am going to replace these parts if that is a better way to go.

What are your thoughts and advice?

Who is raping you $450 for OEM P/C? Do they use KY or is that extra too?

2017 OEM price was $236 or $313 (1209 vs 1211 suffix)

See if you can clean up the OEM cylinder first off, then get an OEM piston/rings ~$70.

E.g. you're better off cleaning up the german silk purse than fussing with a chinese sow's ear.

Before you spend a thing on parts find out what toasted the saw. Pressure test would be a good start if cylinder is still on. If that checks out see if the bottom end is O.K.

 

[Riles32807]

I'm just curious, why replace the piston & rings, but not the cylinder? Seems to me that if your not going to replace the cylinder, then replacing the piston isn't going to do much for you. Wouldn't new rings close off the scoring on the piston? Not trying to start an argument, just want your thoughts.

@BR Wood, this probably sounds daunting, but there are few better ways to learn about your equipment then to dismantle it and reassemble it. There's a lot of very knowledgeable, helpful, & friendly people here at AS. I'm here learning too.

 

[Mad Professor]

I'm just curious, why replace the piston & rings, but not the cylinder? Seems to me that if your not going to replace the cylinder, then replacing the piston isn't going to do much for you. Wouldn't new rings close off the scoring on the piston? Not trying to start an argument, just want your thoughts.

@BR Wood, this probably sounds daunting, but there are few better ways to learn about your equipment then to dismantle it and reassemble it. There's a lot of very knowledgeable, helpful, & friendly people here at AS. I'm here learning too.

The nikasil coating on cylinders although thin are VERY hard and durable. Unless the coating is damaged through to underlying aluminum most cylinders can be saved. The pistons are soft aluminum that wear and/or melt.

This is different from the days of SB and BB chevys/fords, USA made tractors, and small USA engines that were either cast iron or iron lined cylinders. Those you honed or bored out and used oversized pistons

 

[hseII]

I'm just curious, why replace the piston & rings, but not the cylinder? Seems to me that if your not going to replace the cylinder, then replacing the piston isn't going to do much for you. Wouldn't new rings close off the scoring on the piston? Not trying to start an argument, just want your thoughts.

@BR Wood, this probably sounds daunting, but there are few better ways to learn about your equipment then to dismantle it and reassemble it. There's a lot of very knowledgeable, helpful, & friendly people here at AS. I'm here learning too.

Lots of the time, a cylinder will clean up: unless it’s on my saw.

As for OEM or aftermarket, stick with OEM or Caber rings & a Meteor Piston.

That Big Bore Junk is Junk.

 

[Riles32807]

The nikasil coating on cylinders although thin are VERY hard and durable. Unless the coating is damaged through to underlying aluminum most cylinders can be saved. The pistons are soft aluminum that wear and/or melt.

This is different from the days of SB and BB chevys/fords, USA made tractors, and small USA engines that were either cast iron or iron lined cylinders. Those you honed or bored out and used oversized pistons

Thanks. Good to know. Most of what I've been working on have been cheep Chinese junk. The few with scoring, the cylinder has been just as bad or worse than the piston.

 

[John Lyngdal]

This piston looks pretty gnarly, but I've torn down saws that had pistons that looked just as bad, only to find a cylinder that could be salvaged.
I'm a firm believer of running 40:1 with a good synthetic oil and ethanol free gas, and setting the carb to run the saw slightly rich.

 

[Mad Professor]

Thanks. Good to know. Most of what I've been working on have been cheep Chinese junk. The few with scoring, the cylinder has been just as bad or worse than the piston.

Usually mostly Al transfer from the piston, the cyl will clean up in many cases.

Here is a 036 I got for free, the piston was trash but the cyl cleaned up fine, turned out to be a good find

 

[Evan]

I to run 40/1 in everything that burns mixed gas.
I might consider 32/1 on milling saw

 

[BR Wood]

So I called my Stihl dealer and they said they would charge $37.50 to pressure/vacuum test and diagnose my saw. I don’t think that means they will take the piston out and look at the cylinder or not.

Should I go with them to look at it or spend a little more to purchase the equipment to do the test myself ? The biggest advantage is their guy has more than likely looked at this before and will probably tell me if the cylinder is ok if they take it apart.