660 problems

[bushinspector]

Just got back from working a ice storm and lost compression on my new 660 saw. This is the second jug and piston on this saw. Just cutting along and the saw ran out of fuel and would not start. Took it up to the dealer and ran a compression check on it and found it to be only 75 psi and he informed me it was not enough to start it. This saw has only had about 10 tanks that has been run through it. Oil /gas ratio is correct. The first jug and piston was my fault (straight gas was placed in equipment trailer without the oil in it.)The second failure and the second dealer said that the air to fuel mixture was incorrect and caused the failure this time. So I have two questions. Should the dealer that done the replacement jug and piston warranty his repair? And how do you know if the air to fuel mixture is to lean?

 

[2000ssm6]

He should have set the carb before it left and advised you to bring it back after 10 or so tanks of fuel to adjust/check it again. I assume by an incorrect a/f mixture, he meant it was running too lean and scored the p&c? I would buy a tach this time and just learn to check it(the carbs settings) myself, doesn't sound like he explained how you should have taken care of your new p&c.

 

[bushinspector]

Never said a word about anything. Just said it was repaired and ready to go. I am tempted next time to start it up and idle five tanks through it before getting it out to the woods.

 

[jsd176]

It is not good to run a saw out of gas at WOT. The fuel/oil mixture is how the engine is lubricated and if you run it dry at high rpm's there is a good chance you can do some damage.

 

[mtngun]

So I have two questions. Should the dealer that done the replacement jug and piston warranty his repair? And how do you know if the air to fuel mixture is to lean?

The dealer SHOULD have tuned the saw but some dealers don't know how.

Also, it is possible there is an air leak. Shouldn't be, on a low-mileage saw like yours, but it happens. A leak down test should be performed to rule it out.

If you can afford an expensive saw like a 660 then I say you can afford to buy a tach and learn to tune it yourself. I don't trust dealers any further than I can throw them, a lot of dealers sell saws as a sideline without knowing a whole lot about them.

Sorry about your loss. If this jinxed 660 is more trouble than it is worth to you, then ship it to me and I'll pay you a little something for your trouble.

 

[bushinspector]

Just not quite sure that I want to give it up just yet or that easy. So the general way to set up the 660 is to set it up at XXX rpm? I know that somewhere there is a sweet spot between air and fuel mixture but not higher than a certain rpm? Teach me, Teach me, I'm all ears! Thanks for the replys.

 

[mtngun]

Set the H screw to 12,500 rpm with a tach.

A good tutorial at Madsen's.

I should have mentioned earlier, the saw will run leaner in cold weather. So if the dealer tuned it in the summer, then you used the saw recently during an ice storm, it could be expected to run slightly leaner. Only slightly, though, and it shouldn't cause the saw to sieze unless the tuning was on the ragged edge to begin with.

 

[Oldsawnut]

There was a guy on here a while back that kept burning up his 660 due to having the fuel filter in it for the next size smaller saw.. Went threw a few top ends before they figured it out.

 

[bushinspector]

There was a guy on here a while back that kept burning up his 660 due to having the fuel filter in it for the next size smaller saw.. Went threw a few top ends before they figured it out.

Excellent thing to check and never would have ever thought of it. Do you know if it was factory installed or did he place the wrong one in it during maintenance.

 

[056kid]

It is not good to run a saw out of gas at WOT. The fuel/oil mixture is how the engine is lubricated and if you run it dry at high rpm's there is a good chance you can do some damage.

naa, you can do it 100 times & be ok, its just not a good idea.

 

[roncoinc]

What I want to know is this going to turn into a 24 page thread on Stihl saws burning up like what happens when a Dolmar does ??
seems to have been a few lately
probly the STIHL dealer didnt set the saw up right..

" The dealer SHOULD have tuned the saw but some dealers don't know how "
i thought that only applied to Dolmar dealers ??

After only ten tanks of fuel i would be on that dealer like a duck on a junebug with a pevey under one wing and an attorney's bizz card under the other..