middleagemutant
ArboristSite Operative
I had a 310MS Stihl that was doing same thing it was the tank vent damn ethanol and before that had to replace a fuel line that almost disintegrated.
Frustrated: Stihl ms290 dies after heating up
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Scott Kelly
Silverpsd_06
Do yourself a favor and remove the tank vent then try.. Your air filter was wet with fuel meaning tank pressure is overcoming the needle and seat allowing the carb to flow fuel all the time irregardless of the intake opening. It's impossible to restart because it's flooded and runs great for five minutes til it literally starts choking itself on fuel. Best part is that vent is only a dollar or two
Conquistador3
Le Comte de Frou Frou
It's really curious you mentioned that.
My MS290 came with a Champion CJ-8 and given I had no idea to know how it had worked I swapped it out for one of the NGK BMPR7A's I always keep around.
The saw started from cold with surprisingly little effort and ran very well. I turned it off and could not get it restarted.
I put the old Champion back in it and problems disappeared right away.
Exactly the same NGK spark plug works flawlessly in an Echo brush cutter. I am a little stumped: the difference in temperature should not to be so great as to affect restarting.
I have an MS290 completely disassembled on my bench right now waiting on a new piston/cylinder to arrive. Turns out it was running too lean. The owner was bucking up a large log and after a couple of back-to-back cuts the engine seized. Now, what you described sound very similar to what I had happen several weeks ago. Saw would die after cutting for a while. Pull the rope and it would immediately fire up again. Turned out to be nothing more than a bad spark plug. As a result of this occurrence I always replace the plug if I am chasing down a problem with an engine not running, or dying during operation.
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No, they are not okay..... They are the first signs of a lean seizure, and if you keep running the saw without fixing the problem, your next thread will be about rebuilding the saw!!!!!
What he said!!!! The saw I am rebuilding right now was definitely running lean and now the owner is paying the price. Glad I read this thread as I was about to let myself forget to inspect that fuel line. Carb comes apart tonight for a cleaning. Long block to arrive tomorrow! Thanks Harley for the memory bump!!! You might have saved me a warranty repair!!!
livemusic
ArboristSite Operative
Is the tank vent inside the tank? Is it a rubber line or is it a rubber part or just what? I perused my downloaded manual and I do not see page that shows all the parts of the saw. I figured it would show each part. Sorry, I don't know much but I'm trying.
Somebody else mentioned yesterday about taking off the fuel cap after it stops and then put it back on try to start it. I made another attempt yesterday and yes, it ran for 5 minutes and died, just like the day before. I did this three times. Ran 5 minutes, died, wait 10 minutes, go again. I took the fuel cap off and I couldn't tell anything was different. I didn't hear anything if I was supposed to hear hissing air or something like that. Also, I took the spark plug out and looked at it and wow, that sucker was some kinda hot. Is that normal? I could only handle it a bit with gloves.
I got a recommendation for a different mechanic and I am going to take it to him if this does not get solved but I am stubborn and trying to fix it on my own, lol. Upon my next trip going to town which passes the first Stihl dealer, I could buy a spark plug. If that tank vent is cheap and easy to get to, I could buy that.
I just read in my manual that Stihl stated I should replace the fuel pickup doohickey each year. That is a rubber part inside the tank.
If I end up having to just leave with the new mechanic and just have him fix whatever ails it, I am tempted to have him replace all rubber parts, lol!
EDIT: Now, I see someone said that the two faint lines I see in the piston are not good. If that's the case, I will just have to take it to a mechanic. FWIW, these lines are so faint, I don't even think they would photograph.
BTW, when the (first) mechanic installed the new carb, he said the settings would probably be good from the factory. He ran the saw and I don't recall him tweaking the carb settings hardly at all, if at all. It should be set such that it would not run lean now, right? I am going to take th muffler off now and look again at the piston.
Did you try opening up the high adjuster 1/4 turn or so yet( trying that can't hurt), to me it sound like your original dealer has no clue. Steve
livemusic
ArboristSite Operative
I did some carb tweaks a couple days ago but nothing changed. Of course, I know enough to be dangerous. Now, before the mechanic put the new carb on, he DID do a carb adjustment on the old carb when he put the air cleaner on. When he made an adjustment, listening to the sound, it sounded like he made it kinda run a shade rough when revved up high. I asked him about that. I assume that is what I have read about "four stroking" or whatever they call it. So, he does know about that. But I don't recall him doing that after installing the new carb. I assumed it was set perfect. He did cut several cookies of wood. (He ran it maybe 3 minutes, but he did NOT run it 5 minutes.)
livemusic
ArboristSite Operative
I took a pic just now of the piston. These lines are barely visible. I peered over at the far side cylinder wall. I didn't see anything but smooth surface. Did that accomplish anything, lol?
Will try to upload pic now.
Will try to upload pic now.
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If you see slight traces of up/down streaks, that is aluminum transfer, when your saw overheats. Keep running it, and the molten aluminum will start to pin your rings down and you will lose compression.
Just remove your air filter cover, and snap a pic of the air filter, and moreover the fuel line below it. If the line is new, and the carb is new, then your mechanic would be wise to do a leakdown test.
Just remove your air filter cover, and snap a pic of the air filter, and moreover the fuel line below it. If the line is new, and the carb is new, then your mechanic would be wise to do a leakdown test.
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If the fuel line has cracks in it, it needs replaced. And the new carb should be dis-assembled and cleaned.
livemusic
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Do you say that as if all new carbs should get that, or are you saying that because I am still having trouble?
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No, if you have run the saw with a fuel line full of cracks, then there is dirt/crud in your new carb.
livemusic
ArboristSite Operative
Ok.
livemusic
ArboristSite Operative
Is this the "fuel vent?" (See black arrow.) If so, can I remove that with needle nose pliers and then install a new one by just sticking it on there with my fingers or the pliers?
I think this is called "spark arrestor?" This screen... I scraped this red looking stuff offer best I could. I think somebody has been into this engine before and the red stuff is the gasked sealant or whatever you call it. I can see a red bead of stuff and it looks uneven enough to NOT be factory. My question is, do you think this is open enough? To totally remove it, could I soak it in diesel? I don't want to buy any solvent. I could probably buy a new one of these instead of spending money on solvent. I don't think I have any solvent.
I think this is called "spark arrestor?" This screen... I scraped this red looking stuff offer best I could. I think somebody has been into this engine before and the red stuff is the gasked sealant or whatever you call it. I can see a red bead of stuff and it looks uneven enough to NOT be factory. My question is, do you think this is open enough? To totally remove it, could I soak it in diesel? I don't want to buy any solvent. I could probably buy a new one of these instead of spending money on solvent. I don't think I have any solvent.
Sometimes I take the fuel cap off and run the saw on it's side to check the venting. If you put the cap back on and it shortly quits it could be the vent.
Yes, that is the vent and yes, the stuff on the screen looks like Dirko, a sealant Stihl uses to seal the bottom pan to the cylinder. Messy stuff, that Dirko gets on everything. The screen looks clean enough to use. Dirko is kinda fuel resistant but it will wire brush off..
Yes, that is the vent and yes, the stuff on the screen looks like Dirko, a sealant Stihl uses to seal the bottom pan to the cylinder. Messy stuff, that Dirko gets on everything. The screen looks clean enough to use. Dirko is kinda fuel resistant but it will wire brush off..
Try running it without the screen, to me it looks half clogged which would cause too much heat. Steve
Does it idles high or run high RPM's before it dies? If yes, then it's fuel starvation (blocked tank vent) . If it just dies when it warms up, I bet on the spark plug.
Does it have power when cold? Forget the spark screen.
With a cracked fuel line it will also not run properly before it's warmed up.
If you can share your findings we would be able to help better
Does it have power when cold? Forget the spark screen.
With a cracked fuel line it will also not run properly before it's warmed up.
If you can share your findings we would be able to help better
Rookie1
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Im curious. Ive never seen a screen with glue stuck in it like that. I would totally disassemble the engine and check and rebuild properly.
