Small engine trouble

[armylifer]

When you finally get it fixed, no matter if you R&R the current carburetor or replace it, stop using ethanol. That crap is the source of most small engine fuel related issues.

The other thing to do is make sure that you turn off the fuel and let the fuel run out of the carburetor before putting it away. I do this every time with all my small engines as well as my Model T, and I have not had any carburetor issues in more than 50 years.

 

[RCW]

When you finally get it fixed, no matter if you R&R the current carburetor or replace it, stop using ethanol. That crap is the source of most small engine fuel related issues.

The other thing to do is make sure that you turn off the fuel and let the fuel run out of the carburetor before putting it away. I do this every time with all my small engines as well as my Model T, and I have not had any carburetor issues in more than 50 years.

Haven’t followed all of the thread, but I agree with @armylifer - I avoid ethanol gas for any old and/or small engines if at all possible.

Got some carburetor issues with my old Minneapolis Moline that are likely caused by my father putting e-gas in it before I got it.

After tinkering for a couple years, I finally gave up on my own Stihl FS86 Brushcutter because of e-gas. That was my fault because I wasn’t attentive to the problems e-gas can cause. Lesson learned.

Wasn’t commonly available around here for a few years but has been for quite a few years now.

 

[lugbolt]

I have a high $$$ washer, couple 8 or 9 years old now. I only wanted to buy one so I bought a good one

It too does the same thing, only cold. I sold/serviced these things for a good minute. The carbs are EPA rated (thanks to CARB and EPA), they are lean on the pilot circuit and won't really stay running until the engine is hot. Once hot, it's perfect. Mine has an auto throttle, idles down with no load. Soon as you pull the trigger to wash, it idles up. If it's not at operating temp (HOT), it will die when it's loaded and throttles up. Run it on half choke at idle for a while & let it warm up. Problem solved. Inconvenient but I've gotten used to it. I don't bother with trying to richen up the pilot circuit in the carb; if I do that I also have to play with the idle mixture and main circuit-neither of which are adjustable so I'd have to make it adjustable, which entails a whole lot of other things (drilling, etc). Just ain't worth it to me.

may be an issue on yours too. If OHV have you checked the valve clearance? It'll make a difference. Also if it surges when running, it's entirely possible that you have an air leak (aka vacuum leak), so you might look at that too.

 

[JasonW]

I will update this. I ordered a new OEM carb despite the original being spotless. Swapped the new one on with exactly zero change. Same symptoms as before. Will have to dig into it more next week or so.

 

[DaveFromMi]

I have a collection of Stihl power equipment, some from deceased family members.
4 chainsaws: 011, MS180C, MS250, MS290 Farm Boss
3 trimmers: FS55, FS65, FS90
+The FS90 has a 4-stoke engine, but with no oil sump
2 blowers: BG55 and BG56
I use 89 octane fuel (per Mfr) with ethanol, Stihl synthetic oil and 2+ oz of Seafoam per gallon.
The only machine that occasionally gives me fits is the MS180C. It only has one adjustment (idle speed). Every 3 years or so, I just replace the carb.

 

[PoTreeBoy]

I will update this. I ordered a new OEM carb despite the original being spotless. Swapped the new one on with exactly zero change. Same symptoms as before. Will have to dig into it more next week or so.

That points to an ignition problem then. Try a new spark plug if you haven't already, then replace the coil.

 

[MapleLeafFarmer]

after reading all the post i would have guessed a new needle AND seat would be in order. i work on a lot of little motors and amazed at how more so these days than in the past the needle / seat looks 100% but guessing the seat "swell" and does as you said.

BUT

you say you replaced carb so next piece of advice is how is the gasket between the block and carb look? sounds like you have had carb off many times and I see a lot of guys try to reuse the gasket a few to many times which may cause your type of problems.

needle/seat and new gasket OEM kit usually runs around $10 around these parts and surprised how many hours or days guys I know put into trying to fix similar problems but wouldn't spend the $10 bucks and fresh new plug. My crowd is old school and cheap. (haha)

 

[Runs With Scissors]

I too have tried to "rebuild" these small carbs, to no avail.

Although I will freely admit that I have never been good at "carb work", even "back in the day" they frustrated the hell out of me.

For 20-30 bucks, just replace it. The new Chi-Com replacements have worked very well for me at least twice now.