Saw problems

So I bought a 441 cm and to take advantage of the additional warranty I got a pack of Stihl synthetic ultra mix silver bottle The saw in question isn't the 441 I haven't even put fuel in it yet

So yesterday I mixed up a gallon and emptied the saw ms 290 of the gas that was in it which was five days old

I prob should have emptied it the day I was done using it but knew I was going to be using it again shortly and didn't.

Filled the saw up with the new mix and fired it up and let it warm up some. While warming up I notice the chain turning which has not been the case up to yesterday. The last use it ran perfect

Anyways it sounded like it idled high which with the chain moving seemed obvious. I thought ok it's pretty cold out here could that be affecting it some.

So I lightly give it some throttle to warm it up more and to no avail the chain kept right on spinning after I let off the throttle. So I made a couple cuts and it ran like crap.

Shut it off and thought maybe it's the new oil throwing it out of whack. I emptied it and had a partial gal of the orange bottle mix that was only a week old and added it to it. Seemed to help it some not idling as high and the chain did move some.

Ran it a couple cuts same thing ran bad chain running with no throttle.

So I guess my question is it ran fine five days ago. I did switch to the synthetic oil and I did use the winter mix bar oil since it was so cold and as stated before it was cold out.

That was the only changes that I could think would make it run like that. I am not a mech and will be taking it to get checked out adjusted but can anyone give me a idea if switching to synthetic could have messed something up

My other 290 with the reg orange bottle mix ran fine in yesterday's temp so im inclined to think it was the synthetic oil

Could a saw that ran fine five days ago just all of a sudden need a carb adjustment any ideas

 

Nothing is messed up, changing oils will cause you to have to re-adjust the carb for the different mix.
Tune the carb to the new oil and go cut without any worry

 

Cool. I will also admit I can't tune a saw carb. I work on all kinds of things old tractors cars trucks yada yada but I dont mess with two stroke engines. Im going to have the dealer do it

I guess I should just bite the bullet and get a tach and learn to do it myself

 

I don't want to open a can of worms, but I suggest you save your cabbage and tune it in the wood.
I can easily guide you through the adjustments, as can most everyone who frequent this forum, and help you get the most from your equipment free of charge !

 

Dats what I'm talkin' bout! I love it here! Help for everything on just about every level! When the time comes, I'll be in contact about carb adjustments on my 461!

 

Crap I just got back from dropping it off at the dealer grrrrr

Yeah if you don't mind im all ears I have another 290 when the one at the shop gets back I'll adjust it just in case I screw it up I'll have a back up

 

Half the time they dont even check what they do I bet. Adjust with a tac and thats it. Dont check it in wood etc. Probably dont I bet half just tune by ear anyway.

I honestly dont think its the oil..just me personally not saying it can't happen. More likely the temp or the carb is running lean for some reason.

I never dump my saws and 5 day old gas is not old. I have saws that have set for 6 months or a year and start and run fine. I am not saying to do this just pointing out that 3-5 day gas in your carb is not your problem.

And also you needs to learn to tune the saw as tune can be effected by oil and deffinitly by temperature.

I have uses 3-4 different type oils and not had to regime any of my saws between them...maybe I am lucky???

Hope they dont rape you on a $20 deal.

Oops thats another banned word or term at university of michigan. I need to start using "inclusive language"!

 

Woodrat,
The way I do it on a saw that just needs to have the carb trimmed, like your example in the original post (assuming no other problems; like air leak, clogged filter(s), bad gas, low compression, etc..);

1. Start saw and let it warm up (absolutely necessary as a cold saw wont adjust properly)
2. I adjust the low speed screw so when you pork it from an idle there is no stumble (too rich) or hesitation (too lean)
3. Adjust idle screw so chain does not move
4. Open the high speed screw so when you pork it the saw will not get to full speed, but will 4 stroke and be pig rich
5. Go to the wood pile and find a stick that will allow between 1/3 to 1/2 of the bar to be cutting
6. Start the cut so you get into the meat of the stick . She should still be 4 stroking.
7. Release the throttle and turn the high speed screw in just a little. Nail it and cut.
8. If she is still 4 stroking, repeat step 7 until she cleans up
9. Allow the saw to idle and pork it, adjust if necessary (step 2 and 3)
10. Double check the high speed adjustment - you should only need a hair of an adjustment here; if anything

DISCLAIMER: I like my work saws to be on the rich side. I aint cutting cookies or racing anyone, so I prefer to have my saws running on the rich side and stay as cool as possible. If you desire a leaner tune on the high side, your saw will turn a higher RPM unloaded @ WOT, and probably run hotter. Many people tune leaner that I just advised above and have no problems. I have stuff that's going on 40 years old that gets used frequently and the only internal things I have done is to replace some worn out rings. Probably due to running cheap 2 cycle oil, and as of lately I have been running oil that keeps the internals super clean (no carbon deposits on the tops of the pistons) and probably wont be replacing any more rings. Don't want to turn this into an oil thread, so choose your oil and fuel ratio carefully.

IMHO, a properly tuned saw with good mix and sharp chains will last a lifetime

 

Clem, I have personally seen different oils make a tune change at the same ratio.
In the OP, he put the old gas/oil mix back in the saw and the chain stopped moving

 

I missed where he put the mix back in and it stopped again .

Like I said I am not saying it won't happen I just havent seen it. Even when I went from husky XP or woodland pro syn oil to belray I did not see any tune issues. You have way more experience than I..

But I agree I think its a 100% tune issue.

side note , Mopar check out my earthquake tune thread here. Curious about your thoughts.

 

If you're still stuck even after reading Mopars excellent how to; Check the link in my sig for a great explanation of carb tuning (with sound clips) from Madsens. It's what helped me most when I was learning. There's a few good vids on youtube as well that you can hear the "4 stroking" sound on.

 

MasterMech has a good video on youtube about tuneing a saw.

Muffler modds also help you to hear better what's going on. Big saws do as well

 

Yes and yes and yes!

 

Up until 8 seconds you can hear her 4 stroking, including the start of the cut until enough of the bar and chain is cutting, then she runs clean.

@ 17 seconds when I transition off of dogs you can hear it 4 stroke, then again @ 26-27 seconds you hear that 4 stroking sound. That is how all of my saws run, slightly rich, but nice and cool

Woodrat,
In my opinion the tach does not account for the load on a saw, and should only be used to satisfy curiosity. The load should determine the adjustment of the saws high speed needle

 

Here's MasterMech's vid too.

 

Exactly. That earthquake that I am trying to figure out...It will four stroke and make full rpm's but there is NO power in cut.

 

Wow! You went out in this mess!?! And they were open?!?There's a thin line between bravery and insanity.. One can never really be sure on which side of the line he is standing at any given time!

 

WOT unloaded is no test.
Eithor not enough fuel is being delivered under load, or too much air is being delivered

The adjustment screws hint towards an air leak

Vacuum test first, if it fails vac, pressure test to find the leak

If it passes the vac test, the carb has already been rebuilt, more attention must then be turned to fuel delivery.
If fuel delivery is good (which you MUST look into, like a spongy or collapsing fuel line/clogged fuel filter / screen inside carb) then its time for a new carb

 

I was just pointing out if all one did was tune with a tac my saw would be "good" . I am sure most would know that 4 turns out is NOT right!! Haha

 

"I see" said the blind man ..................I thought you were questioning some of the earthquakes troubles