Chainsaw Repair

Husqvarna - Stihl - Poulan - Jonsered - Dolmar chainsaws and more => Stihl => Topic started by: Brian on March 16, 2018, 10:30:57 am

Title: Stihl 066 wonít start
Post by: Brian on March 16, 2018, 10:30:57 am
First I will say I am not a chainsaw repair person, but my local Stihl dealer is backed up about 3 weeks and I need to get this thing up and going again.

So here is what is going on.  The chainsaw just had the trigger/choke buttons replaced with a newer setup from the dealer due to my choke hanging and causing the saw to be difficult to cut off.  They checked it out before that and said it had great compression and the saw when running sounds great.  However, I started cutting with it after I got it back and it started getting hot.  I turned it off when I noticed and started cutting again and the saw started to Bog down and then cut off.  I took it to a small engine repair that said it wasnít getting spark and he replaced the spark plug, air filter and then the coil.  Now when he tests it shows it has spark but we canít get the chainsaw to crank still.  He said he even tried starting fluid and still wouldnít start.  He says it still has good compression.  What would I need to check next?  I am not confident with this guy and canít wait 3 weeks to get it going again.

What are your ideas?
Title: Re: Stihl 066 wonít start
Post by: Cut4fun . on March 16, 2018, 11:27:59 am
For one he should have not been trying starting fluid on a 2 stroke. Use mix in a squirt bottle.

Start checking things.

Pull muffler and look the piston rings over.
Check impulse line, check fuel line and filter.

Check the on/off switch area to make sure not off and grounding out.

Some for starters.
Title: Re: Stihl 066 wonít start
Post by: Brian on March 16, 2018, 11:57:39 am
Thanks, I will start checking those out today.  Air Filter is new, and pulled muffler, there is no screen on this one that I seen and piston looks clean and moves when pulled.  But I will take a pic to show the area when I get home.  I havenít pulled the carb to see if it is clogged, but not sure if I have to replace seals even though I seen videos that make it look moderately doable.
Title: Re: Stihl 066 wonít start
Post by: 3000 FPS on March 16, 2018, 12:38:45 pm
Also I would pull the plug to see if it is wet or dry.

Pull the plug and set it on top of the cylinder sideways put the plug wire on it and then give the rope a good pull.   Look and see if you have a spark on the plug.   

Let us know what you find.   
Title: Re: Stihl 066 wonít start
Post by: Brian on March 17, 2018, 01:39:50 pm
Ok, I have verified spark.  Checked fuel filter, looked at piston head and it moves freely but does have some scratching.  The scratched donít seem to cause restriction. Air filter is brand new and so is spark plug.

I wonder about the repair person I took it to.  He said he adjust the carb before the replacement of the coil.  He only replaced the coil because I asked if it had spark and told him my suspicions when it just cut off after getting a little hot.  So I also wonder about the coil install as well.  I have attached several pics with what I have seen.

Let me know what yíall think.
Title: Re: Stihl 066 wonít start
Post by: Brian on March 17, 2018, 01:40:23 pm
More pics

Title: Re: Stihl 066 wonít start
Post by: Brian on March 17, 2018, 01:41:04 pm
More pics

Title: Re: Stihl 066 wonít start
Post by: Brian on March 17, 2018, 01:41:37 pm
More pics

Title: Re: Stihl 066 wonít start
Post by: Brian on March 17, 2018, 01:42:07 pm
More pics
Title: Re: Stihl 066 wonít start
Post by: HolmenTree on March 17, 2018, 02:52:11 pm
Major lean seizure from looking through the exhaust part.
Title: Re: Stihl 066 wonít start
Post by: Brian on March 17, 2018, 04:35:55 pm
What does that mean to me?  Is the saw dead?  Or does it mean I need to replace a part or two?
Title: Re: Stihl 066 wonít start
Post by: Cut4fun . on March 17, 2018, 05:07:24 pm
Time to find out why and rebuild.

https://chainsawrepair.createaforum.com/stickys-of-how-to-basics/piston-failure-analysis/
Title: Re: Stihl 066 wonít start
Post by: Brian on March 17, 2018, 07:00:58 pm
So it sounds like the carb probably wasnít adjusted correctly.  When the dealer replaced the choke and trigger (new trigger has two coke settings where I swear the old one only had one).  Wouldnít they adjust the carb to make sure it was running correctly before giving it back to me?

And the instructions for lean failure is to change my fuel for the most part or switch to higher octane.  But it sounded like that isnít the only fix.  Sounds like I need to rebuild the motor...
Title: Re: Stihl 066 wonít start
Post by: Cut4fun . on March 18, 2018, 08:09:00 am
Just so you know too. You can put 8 pics per post.  Just click (more attachments) right under where you added last one.
Title: Re: Stihl 066 wonít start
Post by: Brian on March 18, 2018, 12:52:14 pm
Yes I did know that, but the pics from my phone were too large to send at once.  They would exceed the 5mb limit.  Sorry for the the multi replies but that was the only way without editing the quality of the pic.

But outside of that, with a lean side failure (looking at the docs and the piston I agree that is what it sounds like.  The repair guy (who I am not confident in) said it had good compression.  However, I am beginning to wonder how he checked that when looking at the piston there should definitely be at least a loss of compression.

The documents in the link say to clean out the fuel system and adjust the carb.  But with the scoring on the piston I would assume the same is on the cylinder wall and it would lose compression with more use and require at the very least some process of cleaning that up.

And what really makes me mad is I feel that this was caused by the dealer as they replaced the choke assembly and housing.  I used the chainsaw for only an hour before this happened.  Certainly if they adjusted the carb after the put in the new choke then this would not have happened.

So can someone either confirm or give me more information before I go talk to my local Stihl dealer?  I donít want to accuse someone wrongly of not doing a job especially if it should be something I did wrong.

The other information I have read that could also have added to it is I was told by the dealer to use leaded fuel (octane 86 or 87) for my fuel/oil mix.  I even use Stihlís 2 cycle engine oil for the mix.  So if this is what could have cause the issue let me know.

Right now I need to know what I have to replace or fix to get this up and going again, but it doesnít sound like a couple of day fix anymore.
Title: Re: Stihl 066 wonít start
Post by: Cut4fun . on March 18, 2018, 05:54:49 pm
Dont matter to me. Some folks just didnt know it. All good.

Going to be hard to prove it was them. Just saying.   Have fun but it wont be.
Title: Re: Stihl 066 wonít start
Post by: Brian on March 18, 2018, 08:47:37 pm
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.  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.  Not to mention as stated if it is running lean I would need to have someone adjust the carb or find out if there is another problem.

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.

From what I have seen online a replacement head and piston are $119-149 for aftermarket replacements to $450 for an OEM Replacement.

What are your thoughts and advice?
Title: Re: Stihl 066 wonít start
Post by: Cut4fun . on March 18, 2018, 10:15:17 pm
066 660 are worth rebuilds.  I just sold another one for $600 ready to cut.

IMO see if your oem cylinder can be cleaned up and then use a meteor piston kit or oem piston kit.   
Title: Re: Stihl 066 wonít start
Post by: Brian on March 19, 2018, 11:47:56 am
Well with all that I have heard on here I think I will rebuild it then.  If any good mentors out there has time to help me walk through the process I can try to document it and maybe post it somewhere to help someone else if it hasn't been done.  I am wondering what equipment I will need to get to be able to do this outside of regular tools such as a compression/vacuum test kit and such?