Stihl MS180C Headaches - need some help!

[stim141]

Yesterday I stupidly started and ran my MS180C with gas that was a couple of months old. It ran fine then died. Tried new gas - no start or even a cough. Tried carb cleaner - nothing. Gets good spark but I replaced it with a new plug. Took apart carb and cleaned it - diaphrams look pretty stiff and a little distorted - probably due to spraying cleaner. With a small amount directly in the cylinder still nothing. Spark arrester seems clean. Looking in head there looks like some crust on top of the piston.

Tonight picked up a new carb, fuel line and filter - reassembled. Nothing - not even a cough. Fuel is in the line and it seems to be priming but is it possible that the manifold gasket may have gotten messed up with the carb cleaner or staring fluid so I'm not drawing fuel. The cylinder isn't wet with tons of pull in full choke. Or is there some port that could be blocked in the head from the crud on the cylinder?

I'm at a loss here I makes no sense that it would work - even with old gas then get a zero start or even a sputter after replacing the carb and misc parts.

The spark seems good/hot when I pull the plug and arc it.

ANY suggestions would be appreciated.

 

[Trailtrimmer]

Yesterday I stupidly started and ran my MS180C with gas that was a couple of months old. It ran fine then died. Tried new gas - no start or even a cough. Tried carb cleaner - nothing. Gets good spark but I replaced it with a new plug. Took apart carb and cleaned it - diaphrams look pretty stiff and a little distorted - probably due to spraying cleaner. With a small amount directly in the cylinder still nothing. Spark arrester seems clean. Looking in head there looks like some crust on top of the piston.

Tonight picked up a new carb, fuel line and filter - reassembled. Nothing - not even a cough. Fuel is in the line and it seems to be priming but is it possible that the manifold gasket may have gotten messed up with the carb cleaner or staring fluid so I'm not drawing fuel. The cylinder isn't wet with tons of pull in full choke. Or is there some port that could be blocked in the head from the crud on the cylinder?

I'm at a loss here I makes no sense that it would work - even with old gas then get a zero start or even a sputter after replacing the carb and misc parts.

The spark seems good/hot when I pull the plug and arc it.

ANY suggestions would be appreciated.

Does it pop with a little fuel dumped directly in?

 

[cutforfun]

Did you get a new carb from the dealer, is it adjusted right.

 

[stim141]

Nothing. Tried a small amount less than a teaspoon directly into the cylinder then replaced the plug - not even a peep. This is odd because the spark generated from the plug seems excellent when I arc with the plug removed and touching the head.

I doubt that a new out of the box genuine Stihl carb would be bad but it doesn't appear to be drawing fuel.


I'm going to blow out the cylinder and the manifold ports so see if there is something in there. On the port directly behind the carb there are two holes - a single large and beneath it a small passageway that links to a small hole on the carb. If the manifold gasket has a crack in it then it wouldn't draw air/fuel into the carb. I doubt the rings or the head is blown because it worked fine until the tank ran dry with the bad fuel. The black gasket behind the carb seems like its difficult to remove/replace as it seems to be held in place with some sort of ring. Any insight here would be helpful.

Working on it now.

 

[cutforfun]

Is the plug wet or dry when you pull it

 

[fearofpavement]

Try a different spark plug.

 

[cutforfun]

Try a different spark plug.

Thats what i was thinking, also check the spark screen on the muffler

 

[Dan_IN_MN]

Yesterday I stupidly started and ran my MS180C with gas that was a couple of months old. It ran fine then died. Tried new gas - no start or even a cough. Tried carb cleaner - nothing. Gets good spark but I replaced it with a new plug. Took apart carb and cleaned it - diaphrams look pretty stiff and a little distorted - probably due to spraying cleaner. With a small amount directly in the cylinder still nothing. Spark arrester seems clean. Looking in head there looks like some crust on top of the piston.

Tonight picked up a new carb, fuel line and filter - reassembled. Nothing - not even a cough. Fuel is in the line and it seems to be priming but is it possible that the manifold gasket may have gotten messed up with the carb cleaner or staring fluid so I'm not drawing fuel. The cylinder isn't wet with tons of pull in full choke. Or is there some port that could be blocked in the head from the crud on the cylinder?

I'm at a loss here I makes no sense that it would work - even with old gas then get a zero start or even a sputter after replacing the carb and misc parts.

The spark seems good/hot when I pull the plug and arc it.

ANY suggestions would be appreciated.

How's the compression?

 

[stim141]

The carb was purchased at a Stihl dealer - installed out of the box. The chamber seems dry but the carb seems to be getting fuel. I feel it and see it on the carb when I pull it. The plug seems dry. Whenever its ever been flooded you see the cylinder head wet and the plug wet. Not now and its been pulled on position three many times.


I haven't checked compression yet I currently don't have a gauge - but when I pulled the muffler just now and shined a light on the cylinder it appears to have a notch at the top like its worn or cracked off - no scoring really to speak of on the head but ... it doesn't look normal.

I took a photo it looks like the top of the cylinder has disintegrated.View attachment 284063

 

[stim141]

I'm assuming that the cylinder is toast - it shouldn't look that way - almost like it cracked off or is VERY worn. The top seems very "chalky" If I go through the hassle and tear it down and replace the cylinder which I've never done on a saw what would the chances that this thing will ever run again? Would the head/chamber be shot as well? Also how bad is the job to do to remove the head and replace the cylinder?

The saw was used occasionally BUT it was used to cut down three very large birches (two story River Birches (three main limbs) each) and the trees were two plus stories tall). General small limbing and one large pine.

 

[cutforfun]

Piston is toast, it is probably not going to be worth rebuilding

 

[blackoak]

I hope you can take the new carb back because it's not going to fix your problem. You might be able to save your cylinder. Depending on how much damage has happened. If so you can get a new piston and rings and get it going, if not I would probably get a new saw. A piston and cylinder from a dealer will probably cost as much as a new saw.

 

[bcorradi]

I hope you can take the new carb back because it's not going to fix your problem. You might be able to save your cylinder. Depending on how much damage has happened. If so you can get a new piston and rings and get it going, if not I would probably get a new saw. A piston and cylinder from a dealer will probably cost as much as a new saw.

If u need a whole piston and cylinder assembly contact Fish on this site. If your able to get by with just a piston....i haven't personally looked into 017/018 pistons, but I assume there is a hq aftermarket piston manufacturer like meteor making some.

 

[roostersgt]

You can get Episan piston/rings from site sponsors for around $30, combined with new seals and shipping it's about $45'ish, or, you can buy a new OEM engine off the 'bay for $79.99 + shipping. Cheaper than a new lil saw.

http://www.ebay.com/itm/OEM-ENGINE-...337?pt=LH_DefaultDomain_0&hash=item43b8f294a1

 

[stim141]

Thats what I thought. I just saw a video on youtube donyboy73 who did a complete teardown/rebuild of a 250. If the piston/rings are cheap enough I'll do it -

 

[Trailtrimmer]

Thats what I thought. I just saw a video on youtube donyboy73 who did a complete teardown/rebuild of a 250. If the piston/rings are cheap enough I'll do it -

That piston looks pretty melty, don't buy parts until you try cleaning up the cylinder.