ms290 has me puzzled

[no tree to big]

I never thought I would not be able to fix my own saws stihl has found a way

I used it friday to cut up a medium size tree nothing special maybe three 10 foot logs 16-18" diamiter ran great. then I go to use it sunday (this is the part that really pisses me off) I sharpen it first go to fire it up nothing, say screw it throw it back in the truck grab a different saw for the job.

today I try and get er figured out I come to the conclusion its a pos...
has a good spark, tried a couple different known good plugs
is getting fuel
wont pop on starting fluid either
has a near new piston and cylinder which still looks good
tried resetting the carb adjustments(limiters removed)
yes I was using a proper mix
only thing I havn't done is check compression with a gauge (because I don't have one for small engines)



so what ya'll got?

 

[jus2fat]

First off..you shouldn't be using starting fluid..!!

Remove plug and spritz inside cylinder with a little gas/oil mix.

Replace spark plug with a NEW one..a "good looking spark" can be misleading..!!

If you haven't screwed-up the carb settings with your 'adjustments'.....

It should pop..!!..(with the choke OFF..!!)..(then hopefully start and run)
If it won't even pop..well..I dunno..without seeing it..and no compression reading..??
Hope this helps..!!

J2F

 

[bluestripes]

Could be flooded they wont pop even if you use either then. Are the plugs coming out wet?

 

[no tree to big]

Could be flooded they wont pop even if you use either then. Are the plugs coming out wet?

yes they come out wet after I pull and pull. but when they first go in they are dry as a bone



two of the three plugs I tried only have a few hours on them since I had just gone through all my stuff and replaced the plugs and to test them I fired the saw before I pulled it and they worked good enough to fire that saw... the saws even fired up after I put the plug back in it after my testing in the 290. original plug from the 290 even worked in another saw.

and the time I tried the starting fluid was starting with a dry plug

and concerning compression it still feels good (ya I know) piston and cylinder still look perfect so I dont think thats the issue but I will try and get my hands on a compression tester

is there a way for the spark to be "out of time" on a ignition system like this?
flywheel is nice and clean so is the pickup

and concerning screwing up the carb adjustments its not like I'm some nub I have 8?? maybe 10, I lost count, saws all of which I have had to tune because most all of them I picked up in non working condition and they all work just fine well except for one that just wont seem to hold a tune for more then a couple uses

 

[jus2fat]

and the time I tried the starting fluid was starting with a dry plug

I will try and get my hands on a compression tester

is there a way for the spark to be "out of time" on a ignition system like this?
flywheel is nice and clean so is the pickup

You shouldn't use starting fluid AT ALL in a 2-stroke - "this isn't you father's Oldsmobile"..LOL
It strips OFF any oil that is on the cylinder/piston..!!

Take the saw (if you want) to an Advance Auto / Auto Zone...they will check it for free..??

YES..the timing can be off if the the flywheel has slipped. Meaning..NEW flywheel..!!

J2F

 

[no tree to big]

You shouldn't use starting fluid AT ALL in a 2-stroke - "this isn't you father's Oldsmobile"..LOL
It strips OFF any oil that is on the cylinder/piston..!!

Take the saw (if you want) to an Advance Auto / Auto Zone...they will check it for free..??

YES..the timing can be off if the the flywheel has slipped. Meaning..NEW flywheel..!!
"I threw it in the back of the truck"...???

J2F

I dont think auto zone or advanced does compression checks, atleast here, hell they cant even check half the crap they advertise they can check


"I threw it in the back of the truck"...??? NO "I threw it back in the truck" haha and that was after it wouldn't start plus it landed on a bunch of ropes and my gear bag that has all my climbing stuff in it even if I launched it across the road unless you completly shattered the recoil I see no way that would cause damage to the flywheel plus it was only like a foot it traveled I'm sure it takes a much worse beating when I drop it and let the laynard catch it when I have it up a tree


and my dad never had an olds he was a ford man

 

[jus2fat]

I can only say..without seeing your saw..if you try the things I've suggested...
and it still won't even..POP...I would look into the flywheel having slipped..
(not due to your 'replacing' the saw back into the truck..!!..LOL)

It could of just happened...somehow?? But if the timing is off it won't start..or POP.
If you know how..pull the flywheel...if you don't..take it to your Stihl dealer..if he's good..??
Or to a small engine shop that is both competent and also works on chainsaws..!!

I don't know what else to tell you to get your 290 running again.
They're a really tough saw and hold up well...hopefully we're both overlooking something.

Possibly a carb problem..?? These really suck..and I won't touch the subject online..!!

Hopefully..someone else can give you a better direction to resolving your 290 not starting..!!

J2F

 

[VA-Sawyer]

A quick and easy way to check timing.... pull spark plug, get piston at TDC then back up a few degees, magnets on flywheel should be aligned with poles on coil. This won't find if the timing is out by a few degrees, but normally if the flywheel slips, it does so by more than a couple of degrees.

Rick

 

[bluestripes]

Well if its flooded real bad it might not even pop with a new plug. When your pulling it are you pulling it over with the choke on or off?

 

[Great Smokies]

Piston may look good, but did you poke the ring to see if it's stuck? Sounds like you dont have enough compression to make her pop.

 

[Stihlofadeal64]

opcorn:

 

[no tree to big]

Well if its flooded real bad it might not even pop with a new plug. When your pulling it are you pulling it over with the choke on or off?

on off inbetween sometimes full throttle sometimes no throttle sometimes the fast idle setting also I cleared it out when I had the plug out a couple times

 

[no tree to big]

Piston may look good, but did you poke the ring to see if it's stuck? Sounds like you dont have enough compression to make her pop.

actually I did, it was free and I think you may be right which really pisses me off because its a brand new engine in the thing and there is no reason it should have crapped the bed already

 

[Fish]

but did you poke the ring to see if it's stuck?

That's how I lost my wedding ring.......

Almost lost my finger too........

 

[Saw Dr.]

Sounds badly flooded to me. Take the plug out. Turn the entire saw upside down and hold the throttle wide open. Pull it over briskly 30-40 times. Leave it set for a few hours with the plug out. Now put a NEW plug in and start it WITHOUT using the choke. Your carb screws should be about 1-1.25 turns out. Much more than that, and it will flood.

 

[no tree to big]

Sounds badly flooded to me. Take the plug out. Turn the entire saw upside down and hold the throttle wide open. Pull it over briskly 30-40 times. Leave it set for a few hours with the plug out. Now put a NEW plug in and start it WITHOUT using the choke. Your carb screws should be about 1-1.25 turns out. Much more than that, and it will flood.

I'll give that a shot right now sould be interesting to watch...

 

[jus2fat]

actually I did, it was free and I think you may be right which really pisses me off because its a brand new engine in the thing and there is no reason it should have crapped the bed already

Uh-Oh..!!

Did you just say you've re-built the motor..??

If so..did you use OEM parts..?? I mean everything...including piston pin circlips..??

J2F

 

[no tree to big]

Uh-Oh..!!

Did you just say you've re-built the motor..??

If so..did you use OEM parts..?? I mean everything...including piston pin circlips..??

J2F

I bought a "new" engine but pretty sure it was rebuilt piece I know it was a oem piston and jug not sure on the rest

 

[sefh3]

After you unflood the saw, check your carb settings. If they are out more than 1 - 1 1/4 turns it will flood everytime.

 

[sefh3]

When you put the flywheel on your "new" engine, did you make sure the keyway was still attached to the flywheel? Also, did you torque the nut down?

Loose flywheel=stripped keyway= spark but at the wrong time.