Everything I hate about my new MS290

[dallypost]

I have a fairly new MS290 that ran great for about two years. When it quit running I replaced the plug, fuel line , fuel filter and put a carb kit in. I tuned H by starting one turn out. Then I started it and slowly moved toward lean until I got max rpm at full throttle. Then I opened H 1/2 turn. When I put it in wood, it did not have much power and smoked a bit. I turned H about 1/8 toward lean and tried again. It cut great and quickly finished off a chord of wood. Then without warning, it stared to burble badly at full throttle and had no power at all.

The air cleaner looks pretty dirty so I will clean it and try again. I was frustrated that I could not clean the filter in the woods. I really miss the foam filters that were so easy to clean while on the job. Does someone make a foam replacement for this saw.

I am also curious about what else may have caused this saw to go from running great to running so poorly in just a matter of minutes. Any ideas?

 

[stihl_collector]

Why was there no L circuit adjustment?

 

[MNfarmer]

Sorry to hear about all your 290 problems. I have had zero problems with mine. Could there have been any way that your gas got contaminated with something?? Water, dirt, straight gas??? Just some ideas. Hope you figure it out!!

 

[Tzed250]

Never adjust a carb when the filter is dirty...


.

 

[blsnelling]

You need to have someone tune the carb that knows what they're doing. It's not the saws fault that it's not tuned right.

 

[stihl_collector]

Brad is right there.

 

[dallypost]

My answers

I tuned the L and H according to instructions that I got here in another thread.

Started L at one turn open. Then I slowly closed it until it started to fall off lean. Then I opened it 1/2 turn and adjusted the idle. I did not mention this because it did not seem to be a problem.

I did clean the air filter before tuning the carb.

 

[stihl_collector]

Always tune to rich not to lean, lean = hot-rich = cool.

 

[dallypost]

I did tune to rich. It was smoking and had little power. I then went 1/8 turn to lean and it seemed to gain power and cut well. It also had a pretty good burble when run at full throttle while not in wood

 

[stihl_collector]

What 2 stroke ratio are you running?

 

[dallypost]

I use those small stihl two stroke oil bottles and pour one in a two gallon gas can. The oil bottle says it is good to 2 to 2.5 gallons of gas.

 

[dallypost]

In a previous post, someone suggested that I take the saw to someone for a tuneup.

I live on a remote horse ranch in Idaho. If tomorrow morning I decide that I want a Whopper with Cheese, or a new shirt from Wal-mart or a person that knows about saws, it is a two hour road trip. As a result, we tend to do things ourselves. If anyone can help me sort this out, I will appreciate it.

I suppose that I need to do some trouble shooting first. Tomorrow, I will take the following steps and see if any help:

1. Clean the air filter
2. clean the spark plug
3. check the spark arrester
4. after that , I suppose that I could go through the carb again on the off chance that i left a bit of crud in there that may be causing a problem.

I will let you know what I find

Oh, I should mention that the saw has very good compression.

Can any of you think of anything else that I might look at?

Thanks

 

[tmessenger]

Sound like the saw it a few years old when was the last time it had a new plug and new air filter ?

 

[outdoortype]

Not a carb tuning issue

Your carb tuning procedure sounds good to me. The fact that it ran great for any length of time tells me its not a carb tuning issue. If it were tuned incorrectly, it would have been noticeable right off the bat. Maybe the carb is sucking dirt from the inside of the tank? Or maybe something is failing inside the carb such as a diaphram sticking. I would try to find a known functioning carb-you might just bite the bullet and buy a new one. I was also thinking that an air leak that only shows up when the saw is hot. But I would think that the saw would over rev if were an air leak.

 

[Brushwacker]

I have a fairly new MS290 that ran great for about two years. When it quit running I replaced the plug, fuel line , fuel filter and put a carb kit in. I tuned H by starting one turn out. Then I started it and slowly moved toward lean until I got max rpm at full throttle. Then I opened H 1/2 turn. When I put it in wood, it did not have much power and smoked a bit. I turned H about 1/8 toward lean and tried again. It cut great and quickly finished off a chord of wood. Then without warning, it stared to burble badly at full throttle and had no power at all.

The air cleaner looks pretty dirty so I will clean it and try again. I was frustrated that I could not clean the filter in the woods. I really miss the foam filters that were so easy to clean while on the job. Does someone make a foam replacement for this saw.

I am also curious about what else may have caused this saw to go from running great to running so poorly in just a matter of minutes. Any ideas?

Fuel lines crack on them fairly frequent from what I hear and have experianced on occassion.

 

[dallypost]

I replaced the plug, cleaned the spark arrester, replaced the fuel line and fuel filter and put a carb kit in the saw and it has only cut one chord since then. The only thing I noticed when it stopped running was that the air filter looked really cruddy. But I doubt that this is a problem because the filter was carefully cleaned and only cut one chord since that cleaning.

 

[dallypost]

Sound like the saw it a few years old when was the last time it had a new air filter ?

The filter is original equipment. I really miss the old style foam filters. They are so easy to clean in the woods. Is their a replacement "foam" filter for this saw?

 

[dallypost]

This may be a silly question, but here goes. When I put the carb kit in, I removed those silly limit caps and threw them away. I was surprised to see that the needle valves did not have springs on them. They are held in place with friction only. I wonder it the needles could be moving with vibration, which finally untunes the carb.

 

[Fish]

To get a good grip on proper adjustment, you need to remove the red
limiter caps.

But first, to be sure of things, remove the muffler and look at the piston.

If all looks good, go into the carb again, and this time when it is apart, remove the needle/lever/spring and hold the carb up to a light and look through the passage that the needle closes, you should be able to see
light through it.
Blow out that passage with air or carb spray and hold it up to a light again and visually verify that it is clear, then reassmble and try it again.

 

[Fish]

Wow, that was some timing.

No, they won't move, but you should do the other things I suggested though.

With cracks in the fuel line, crud collects in that passage and will let some
fuel through, but will cause trouble when running and trying to adjust.