Dead Stihl ms180

[Robin Rowley]

This saw is a year or so old. Saw was running and cutting great and just quit, like I had switched it off. Wouldn't restart. After appropriate verbal abuse I let it sit overnight. The next day it started up and again ran and cut great for about an hour until it died again. This time it won't restart after several days rest. It does have spark. Air filter is clean. Newly mixed gas with 93 octane non ethanol. I'm not even sure where to start looking to diagnose this problem. Can anyone give me some guidance?

 

[epo]

What is the condition of the spark plug after removal? Is it wet or dry?

 

[Robin Rowley]

Didn't look too wet to me, but I'm no expert.

 

[Oletrapper]

Didn't look too wet to me, but I'm no expert.View attachment 1177967

Looks kinda cruddy to me. If it's wet at all, might not be firing. Put a new NGK in and see what happens. jmho OT

 

[Robin Rowley]

I happened to have a backup on hand. Still no start

 

[Oletrapper]

I happened to have a backup on hand. Still no start

At this point, it may be flooded. Take the plug out and let is sit for awhile. Couple days. Are you sure you have spark? Put boot on spark plug, lay plug on top of cylinder and pull. You should see the electrode gap spark.

 

[Robin Rowley]

Yep, I'm sure about spark.

 

[Oletrapper]

Yep, I'm sure about spark.

I would let it sit with the plug out and the plug hole down. If flooded, that should allow the fuel to leave the crankcase. May take awhile. jmho OT

 

[Bob Hedgecutter]

Lets see a nice clear photo of the piston face as viewed through the exhaust port with the muffler off.

 

[Oletrapper]

Lets see a nice clear photo of the piston face as viewed through the exhaust port with the muffler off.

I was headed there but not too sure of the OP's ability at this point. lol OT
And then there is the carb to consider. Stated the saw is a year or so old. Which means to me 3 to 4 or maybe more. Time flies.

 

[Wood Doctor]

I ran into this problem with a Stihl 180 a few years back. I changed out the carb and that solved the problem. Those carbs were hard to find back then. The owner was very satisfied and it still runs well today.

 

[Robin Rowley]

Ok, Mr. Trapper, I can take a muffler off , but it'll be tomorrow. I've already had my shower and don't want to get greasy again. And come to think about it, I've had the saw a year last christmas. Or was it 2 years? Anyway the saw doesn't have a lot of hours on it. Maybe an amazon carb is in my future....

 

[ballisticdoughnut]

Ok, Mr. Trapper, I can take a muffler off , but it'll be tomorrow. I've already had my shower and don't want to get greasy again. And come to think about it, I've had the saw a year last christmas. Or was it 2 years? Anyway the saw doesn't have a lot of hours on it. Maybe an amazon carb is in my future....

Do not buy a Amazon carb get OEM.

 

[Robin Rowley]

Bob W.-when you say piston face do you mean the top of the piston or side? I don't see how I can get a shot of the top of the piston..? The top of the exhaust port is in the way.

 

[Robin Rowley]

Best I could do. Hope this helps.

 

[Vintage Engine Repairs]

No, photo the piston skirt through the exhaust port. However that plug is carboned up and that much unburnt oil / gas in the exhaust port is likely related to your issue.

 

[Bob Hedgecutter]

Bob W.-when you say piston face do you mean the top of the piston or side? I don't see how I can get a shot of the top of the piston..? The top of the exhaust port is in the way.

If you think of the piston in relationship to the human head- face is the front side, not the top.
Your photograph shows plenty of carbon build up- which is not ideal, but not hugely bad either- means it has not been fed regular diet of lean fuel mix!
More concerning perhaps is the oily gunge around the cylinder flange bottom of fins. That could mean a loose engine pan and air leakage problems- or it could just mean someone has bad aim with bar oil topping off the tank.
Either way, front face photo of the piston would be nice still.

 

[stihltech]

I guess it could be this. Or it could be that.
Time for real diagnosis. Does the saw stay up when held by the starter handle? If it does, compression MAY be OK.
A good pic of the face of the piston (or side if that makes more sense} will help, especially now that the muffler is off.
Pour gas into a clear jar to check for water. Yeah, I know, everybody has good fuel. That is why I find it in 3/4 0f the saws that come in the shop.
How does the screen look in the muffler? Real common issue on these saws.
If you grab the cylinder by the top, can you move it in the motor housing? Another thing I see.
More to come. Let us know.

 

[rogue60]

Looks flooded? Or Oiled up from running without a decent load along with half or less throttle?. Put a new/cleaned plug in and hold the throttle wide open and pull it over until it starts.

 

[Robin Rowley]

Thanks for your attention guys. Here's the piston "face"