Stihl MS250 running poorly...

[Hooterspfld]

Ok last time I used my MS250, it worked perfect plenty of power etc... Tried to run it the other day and it was pretty weak. Would get started and run only if I kept it at full throttle, but still weakly and blowing lots of smoke. Decided my gas was had too much oil in it. So I emptied the tank, and removed the spark plug, replaced to no avail. in doing so, the coil wire came apart. So I replace the coil and plug and put new fuel in it and start it up and it has the exact same symptoms. Pulled the plug and after 5 minutes of running seemed to have too much oil on it in my opinion... 

Any ideas? I'll try and upload pics of the plug. Did I damage the saw by running to rich an oil mixture?

Any ideas would be great, I hate to just take it to the shop, prefer to gain the knowledge by trying to fix it myself. Thanks for the help!

Top pic is the Bosch plug I took off first. Next two pics are brand new NGK plug after running poorly for like 5 minutes.



 

 

 

[Hooterspfld]

Also, $650 for MS650 Magnum. Good deal or keep looking?

Link removed by Admin - No Craigslist Ads permitted 

[lxskllr]

Dunno about the value of the Stihl, but the bar's missing a lot of paint for not being used much at all>

[sawguy21]

Check the spark arrestor screen, it may be plugged with carbon.

[Hooterspfld]

I don't think the screen was the issue. I've cleaned it but it really wasn't very dirty. I don't know if the video will load, but saw is running at like 50% rpm and still dies as soon as throttle is lowered. Also swapped out the fuel filter while I was at it. Doesn't want to start at all now, getting tired and frustrated now, so gonna put it down for the night. 

[dougand3]

Looks very rich/fat. Have you tuned carb? Turn in/CW 1/8-1/4 on L & H and see how it does. If carb has a fixed H, get a fully adjustable carb. ~$8 online. Lots of videos on youtube "Tune a chainsaw carburetor"

[motzingg]

sounds like the metering diaphragm or the check valve in the carb has failed.

its pumping extra fuel into the engine, essentially the 'float' is sticking open.  that will give you the wet/dark plug, and a condition where it runs smokey and sputtery and only at full throttle. 

commonly damaged by ethanol but they can go from just aging too. 

[Hooterspfld]

Thanks guys, yeah I'm thinking carb issues as well. I ordered a replacement carb, should be here in a couple days. I'll update after new carb is installed. Thanks for the advice!