Stihl MS290 and MS360 Need Advice

[kjalaska]

Ok this is my first post as I just joined forum but have lurked around and read for several years now. Appreciate all the good info on this forum! Lengthy post but I’ll try to shorten it.

1. Have a Stihl MS290 that is about 6 or so years old bought new and not worked too hard. Did a little muffler mod, nothing crazy and adjusted high screw to where it just sputters at full throttle but cuts smooth in cut. Saw runs great, get some cutting done and shut it down. Go to re-start it and dozens and dozens of pulling? Cannot figure it out, have good spark, good fuel? It is not an easy starting saw cold but will usually pop on 4-6 pulled with choke on then first or second pull after disengaging choke. Once warm, I do not choke but have tried both ways and she just does not want to start. Any ideas? At my age I need saws that will start after a few pulls.

2. I just bought a used MS360 power head only, was a used government saw a guy bought in a case lot auction. I gave $250 for it as it started up after just a couple of pulls, seemed to have good compression and ran decent. I killed it and re-started several times. Anyways, bought the right Stihl 20” bar and chain, bring it home and cannot get it started after couple dozen pulls! Supposedly saw was gone thru by a Stihl dealer? I pulled plug and it is new, new air filter, getting spark (white not blue if that matters). I am by no means a chainsaw mechanic but can do some basic work. What is the number one cause of chainsaws being fickle and hard to start? I also noticed the carb has the limiters on it which surprised me me on a saw of this age, think I read they were only made from 2000-2003? I was thinking of trimming the tabs but thought I should ask on here first. My MS290 did not have limiters and it is a newer saw?

This is my 4th Stihl saw, have a 025 and a 026 both bought used and both needed replacement carbs. I am at the point where I have to take out 3 saws to get one truck load of wood cut as the 026 gave me problems last time out. Other than the MS290 the other saws were well used so maybe that is part of my problem, but still getting very frustrated with saws that an old guy has to pull the cord dozens of times to start. Ideas are welcome and thank you! I use premium non ethanol fuel with Stihl synthetic oil but mix it 40:1 as a chainsaw mechanic said was good idea for extra protection. Wondering if the 40:1 mix could be a problem as I think all my saws call for 50:1?

 

[sb47]

Welcome to the site.
One thing I have learned about stihl saws is they flood very easy.
All my saws start best when I put them on full choke and pull once maybe twice till it tries to fire. Once it tries to fire on full choke DO NOT PULL IT AGAIN, UNTIL YOU MOVE IT TO RUN or it will flood every time. Once flooded they take a long time to clear out. I stress this very strongly. Once it try's to fire on full choke DO NOT PULL IT AGAIN ON FULL CHOKE. Move the throttle to run before you pull it again. You also need to pull it with some gusto. Don't be a wimp, give it a good hard pull.
As for fuel mix I always use stihl oil in the one gallon pre mix bottle and mix only one gallon at a time. I think it 50:1 but a tad more or less shouldn't make much difference on starting performance. Very rarely do I mess with any of the fuel screws. The only one I have ever had to adjust is the idler screw, and that has been very rarely do I have to do that. My newest 261-c starts so easy it's almost comical. One pull on full choke, and one pull on run.
If you have been turning fuel screws it just may need to be reset to the stock setting. But they are used saws and who knows whats been done to them.
I'm old school and hate a hard starting saw, If thats the case I sell it and get another saw. I'm all for easy starting saws, and I don't care to try to squeeze out the best performance. If it starts east and runs decent, leave it alone.

This apples only to cold starting, if the saw is wormed up bypass the choke setting and just put it on run.

 

[HarleyT]

I would suggest that you start with a new batch of fresh fuel.
Older fuel is bad news, and can by itself make for hard starts.

Also the formulation changes with the seasons.

 

[SuperDuty04]

Sell them all and buy a CM model. Mine starts on the 1st or 2nd pull every time.

Since the issue spans so many saws, my first thought would be that it’s fuel related. Try buying a can of a quality pre-mix and see if things change. That’s all I run in my saws. I wish I could offer better advice to your specific issue but I don’t have the knowledge as these other guys do. Hopefully they’ll help you figure things out.

 

[kjalaska]

Thanks for replies. Think the fresh gas might be a good start as I am finishing up a can mixed several months back when weed wackers and chainsaws were being used daily. The more I think on it I might try and go back to 50:1 with the good Stihl synthetic oil. I have learned that my Stihl saws flood very easy and only pull on choke until it fires once. Would anyone know about the limiters on the MS360? They only have about 3/4 turn adjustment.

 

[HarleyT]

Look in here.

 

[BangBang77]

I would throw the Stihl oil in the nearest dumpster, buy some Echo Powerblend, Echo Red Armor, or Yamaha 2R, grab some fresh gas, mix it 40:1, and refill your saws.

If you jump from 40:1 to 50:1 and vice versa, you will need to re-tune your carbs for various ratios. I run the 3 oils above, mostly Powerblend, at 40:1 in everything from my 261c to my 066 to my string trimmers- I prefer the higher oil:fuel ratio as I think it protects the engine components better. Gasoline formulations also change from summer to winter and back again so using fuel that was mixed a few months ago may be part of your problem as well.

I would also pull the limiter tabs from the 360 and retune saw.

 

[HarleyT]

Echo oil is for wussies!!

 

[BangBang77]

It is what it is...

 

[sb47]

I would throw the Stihl oil in the nearest dumpster, buy some Echo Powerblend, Echo Red Armor, or Yamaha 2R, grab some fresh gas, mix it 40:1, and refill your saws.

If you jump from 40:1 to 50:1 and vice versa, you will need to re-tune your carbs for various ratios. I run the 3 oils above, mostly Powerblend, at 40:1 in everything from my 261c to my 066 to my string trimmers- I prefer the higher oil:fuel ratio as I think it protects the engine components better. Gasoline formulations also change from summer to winter and back again so using fuel that was mixed a few months ago may be part of your problem as well.

I would also pull the limiter tabs from the 360 and retune saw.

Whats wrong with stihl oil?

 

[BangBang77]

If you run it at 40:1 or lower so it lubricates the bottom end sufficiently, I've had it gum up my mufflers. It will then leave excessive carbon inside the muffler, which if it makes it into the p&c, you end up with carbon scoring.

I just don't think it burns clean enough at 40:1 for me. And if you run it at 50:1 to minimize carbon buildup in the exhaust, I don't think it lubricates the bottom end enough.

Just my two cents. Wasn't trying to start an oil war...

 

[Mad Professor]

If you run it at 40:1 or lower so it lubricates the bottom end sufficiently, I've had it gum up my mufflers. It will then leave excessive carbon inside the muffler, which if it makes it into the p&c, you end up with carbon scoring.

I just don't think it burns clean enough at 40:1 for me. And if you run it at 50:1 to minimize carbon buildup in the exhaust, I don't think it lubricates the bottom end enough.

Just my two cents. Wasn't trying to start an oil war...

Just use this at 20:1

 

[sb47]

If you run it at 40:1 or lower so it lubricates the bottom end sufficiently, I've had it gum up my mufflers. It will then leave excessive carbon inside the muffler, which if it makes it into the p&c, you end up with carbon scoring.

I just don't think it burns clean enough at 40:1 for me. And if you run it at 50:1 to minimize carbon buildup in the exhaust, I don't think it lubricates the bottom end enough.

Just my two cents. Wasn't trying to start an oil war...

I have a ms290 for over 15 years, still running the same stihl oil I did when new. It even has the same original spark plug from when new. I could only guess how many hours it has on it. Hundreds possibly thousands of hours.
Still starts and runs like new.

 

[kjalaska]

Thanks for the replies. I made up a fresh batch of gas using Stihl Ultra (already have a 6 pack on shelf) and split the difference at 45:1 since there seems to be a split between the 50:1 and 40:1 crowd. I was thinking too that in case the gas pump was off a bit would be insurance on not going over 50:1. Also used premium 90 octane pure gas as we do not get ethanol here in Alaska. Bad gas might have been big part of my problem. 026 and MS360 running strong now and cannot wait to get out to cut again to fine tune the carbs. I also removed the limiters on the 360 as I did not have enough adjustment to get it running smooth. Pretty happy now with the $250 I gave for the MS360. Guy has 2 more but not sure I need more 60cc saws, but....??

 

[Agent smith]

I run Stihl hp ultra in everything with non ethanol fuel. Thats the ticket in keeping power equipment running. Ethanol fuel dies within 30 days and will make small engines run like complete poop dooky if its not used right away and will cause hard start problems if the ethanol fuel is old not to mention it will destroy carb diaphragms. Long ago i couldn't figure out why i was having so many carb problems on my equipment and an old timer told me it was the junk ethanol fuel. By golly that old fart was right! No problems since i switched everything over. Also you can never have too many saws! If he has two more scoop them up

 

[sb47]

I run Stihl hp ultra in everything with non ethanol fuel. Thats the ticket in keeping power equipment running. Ethanol fuel dies within 30 days and will make small engines run like complete poop dooky if its not used right away and will cause hard start problems if the ethanol fuel is old not to mention it will destroy carb diaphragms. Long ago i couldn't figure out why i was having so many carb problems on my equipment and an old timer told me it was the junk ethanol fuel. By golly that old fart was right! No problems since i switched everything over. Being you cant get non ethanol fuel by you I'd buy and mix only what you will use in a short amount of time

I will have to disagree with part of what you said. I have had ethanol fuel for much longer then 30 days, sometimes up 5/6 months with no issues at all. In fact I just used some ethanol fuel today that has been sitting for 4 months and it ran just fine.
Here is the real skinny on ethanol fuels. Gas itself will not mix with water. The alcohol acts as a emulsifier, allowing water to blend with the gas/alcohol mix. It's an old truckers trick . If a trucker gets some water in there diesel tank they will add alcohol to allow the two, to mix and the diesel alcohol mix will run through the system and still burn without having to drain the tank. It's more of a problem in cold weather when the water that sits at the bottom of the tank freezes, and blocking the fuel line.
An emulsifier is something that will allow two fluids that would not normally mix, to mix and blend together.
Because alcohol is in the fuel, it will allow the moisture from the air to mix with the fuel, increasing the water content in the fuel. Because fluids expand and contract with temperature, if you have a tank that is half full it will pull air in and out of the tank as the temps change. Over time that allows the humidity in the air to mix with the fuel, making the water ratio increase over time. What you end up with is a fuel with a high water content and that is where the problems begin, causing corrosion in carburetors.
Always keep your fuel tanks topped off so expansion and contraction can't pull air in and out of the tank. That will reduce the opportunity for humid air to transfer moisture to the fuel.
Non ethanol fuels still pull in moisture fron the air, but instead of blending with the fuel, it will condensate on the sides of the tank and sink to the bottom but not mixing with the fuel.

You can try this experiment yourself in a glass jar. Put some non ethanol fuel in and then add a little water. The water will sink to the bottom rite away. Then shake the mix up and let it set still for a min and the water will quickly sink to the bottom again, because the two won't mix. Now add a little alcohol to it and shake it up again, and presto the water mixes with the fuel and disappears.

 

[Agent smith]

I will have to disagree with part of what you said. I have had ethanol fuel for much longer then 30 days, sometimes up 5/6 months with no issues at all. In fact I just used some ethanol fuel today that has been sitting for 4 months and it ran just fine.
Here is the real skinny on ethanol fuels. Gas itself will not mix with water. The alcohol acts as a emulsifier, allowing water to blend with the gas/alcohol mix. It's an old truckers trick . If a trucker gets some water in there diesel tank they will add alcohol to allow the two, to mix and the diesel alcohol mix will run through the system and still burn without having to drain the tank. It's more of a problem in cold weather when the water that sits at the bottom of the tank freezes, and blocking the fuel line.
An emulsifier is something that will allow two fluids that would not normally mix, to mix and blend together.
Because ethanol is in the fuel, it will allow the moisture from the air to mix with the fuel, increasing the water content in the fuel. Because fluids expand and contract with temperature, if you have a tank that is half full it will pull air in and out of the tank as the temps change. Over time that allows the humidity in the air to mix with the fuel, making the water ratio increase over time. What you end up with is a fuel with a high water content and that is where the problems begin, causing corrosion in carburetors.
Always keep your fuel tanks topped off so expansion and contraction can't pull air in and out of the tank. That will reduce the opportunity for humid air to transfer moisture to the fuel.
Non ethanol fuels still pull in moisture fron the air, but instead of blending with the fuel, it will condensate on the sides of the tank and sink to the bottom but not mixing with the fuel.

You can try this experiment yourself in a glass jar. Put some non ethanol fuel in and then add a little water. The water will sink to the bottom rite away. Then shake the mix up and let it set still for a min and the water will quickly sink to the bottom again, because the two won't mix. No add a little alcohol to it and shake it up again, and presto the water mixes with the fuel and disappears.

I see what you're saying and i don't need to do Bill Nye the science guy experiments over here. I was just simply stating what i found out for myself. Started using non ethanol fuel and my problems were gone. Everyone's experiences will be different im sure. Here in ohio the ethanol fuel is garbage. Somewhere else it might be better and last longer. Idk

 

[sb47]

I see what you're saying and i don't need to do Bill Nye the science guy experiments over here. I was just simply stating what i found out for myself. Started using non ethanol fuel and my problems were gone. Everyone's experiences will be different im sure. Here in ohio the ethanol fuel is garbage. Somewhere else it might be better and last longer. Idk

I'm sure location and how long the fuel sits at the gas station has a lot to do with it. Gas station tanks tend to be very large and in some locations it may sit in those tanks a long time before it gets bought by the locals. In other words, a low turnover before a new shipment is received.

 

[sb47]

I just had that issue a few weeks ago. Bought some new fuel and my splitter started running like crap and cutting out. I thought maybe the carb was going bad. I drained the tank and bought some new fuel from another place and the problem went away. I just got a bad batch of fuel.

 

[Bob Gregory]

I work on a lot of different saws, and at some point they get where they do not want to restart after running a tank of gas out of them. On newer saws that have this problem, I will open that plug up an extra three or four thousands. On saws that have mild to slightly heavy use on them, I will open up that plug 5 thousands. And on very heavily used saws, I will open up that plugs 7 thousands. This makes for a stronger spark as it takes more energy to bridge the gap. Some of you will say this Robs from the very high RPM, and I cannot disagree that it does slightly,and on some brands of saws it's more noticeable than others. But I can assure you that little bit you sacrifice on the top end will be justified on you not pulling your brains out to get your Saw running again when you need it! And besides, your saw shouldn't be running at 11 or 12000 RPMs when it's in the cut anyways, it should be around 8,000 with a load and 4 stroking...the beautiful thing about it is , it doesn't cost you a dime to open or close the gap on the spark plug...