Cannot keep the 422 running

[MuncyBob]

Well, in hindsight I should have pulled the elbow fitting from the bottom of the tank yesterday because there was further debris in there. I was so sure the visible crud in the tank was the only problem. It's all good now.........Moss, que the songbirds and sunshine

 

[ponytug]

You aren't the first, or I am sure, the last person to have that issue.

I am glad it is fixed!

All the best, Peter

 

[MossRoad]

 

[2manyrocks]

I've been surprised at the amount of crud that I find in this fuel funnel filter after refilling my ZTR. I also use it to filter my diesel, too.

Amazon.com

 

[marrt]

I realize this thread is solved. However, a stuck fuel cutoff solenoid on the carburetor will also cause this problem, for any future troubleshooters. It lets just enough fuel in to start and run, but not enough to keep running.

I found this problem on one of my machines, even though I put in a lot of fuel conditioner at the end of the season. I had a spare carb laying around and the solenoid was stuck on that carb too. Easy to take off and clean the ethanol varnish out.

To diagnose, put your finger on the solenoid and turn the key on. You can feel (and usually hear) it retract from the main jet.

As of this year, I've finally thrown in the towel and only run ethanol-free gasoline. Costs about $1.50 more per gallon but I've wasted way too much time over the years with carb cleaning.

 

[MossRoad]

Honest to goodness, I've been running E10 since the 80's in everything I own. Vehicles, motorcycles, lawn equipment, IH2500B, and PT425.

I've had one carb issue on a 1970 Nova 1 barrel, way before E10. I had a weed eater I replaced the carb on for $15. That's it.

Every time I've thought it was a carb issue, it was something else. Fuel pump. Fuel filter. Fuel pickup in tank. Stuck/bad choke. Fuel solenoid. Fuel line. But never carb.

Of course, now one will fail tomorrow.

 

[marrt]

I think emission regulations forced carb changes, making them more sensitive to contamination. I have three Honda engines and ALL run rough (surging at idle). I've cleaned those carbs so many times that I just ignore it.

On some engines, a little extra choke helps them to run better. I cranked a Yamaha engine on a generator recently, and it wouldn't idle without cracking the choke open a bit. That engine has fuel treatment, and the carb was cleaned two years ago to fix same problem (which it did). But the generator sits unused for long periods.

I have a Chinese engine on a plate compactor that always starts, even with old gas. My dad has a Merry tiller that's the same. But it's 50 years old.

In my experience, carburetors on newer machines from reputable engine manufacturers (that are designed to meet emissions standards over the life of the engine) are very sensitive.

 

[MuncyBob]

Since switching to e-free gas my 422 runs better, seems to use a bit less fuel than before and shuts down w/o a backfire...which previously happened a lot unless I let it run on low idle for at least 30 seconds before shutting down. Once when getting a refill a Mercedes owner told me that he only runs e-free in his car and said he gets better mileage. I thought to myself, you better for what it costs!

 

[ponytug]

Since switching to e-free gas my 422 runs better, seems to use a bit less fuel than before and shuts down w/o a backfire...which previously happened a lot unless I let it run on low idle for at least 30 seconds before shutting down. Once when getting a refill a Mercedes owner told me that he only runs e-free in his car and said he gets better mileage. I thought to myself, you better for what it costs!

That's good news.

There is a slight difference in energy between Dino oil gasoline and E10. It is not a lot and may be up to 4% in energy. That arises because ethanol is about 76,000BTU/gal, and Dino oil is closer to 120,000BTU/gal, though it can be lower depending on the feedstock and refinery. However, ethanol has a higher ignition point and a higher flash point both of which tend to lower knocks.

https://afdc.energy.gov/files/u/publication/fuel_comparison_chart.pdf (the last lines on the first page are the ones covering energy) The higher energy per gallon (or per unit weight) is one reason why long haul truckers prefer diesel. More energy per gallon translate to greater range for the same weight on board.

FWIW: Many areas switch between higher volatility gasoline for winter use and lower volatility gasoline for summer. So you can get "performance hangovers" for using a winter fuel fuel in summer and vice versa if you use out of season fuel. Summer fuel is hard to start in the winter time and winter fuel is prone to knocking and backfires when used in the summertime. It is not usually a big effect, but can be especially noticeable on some engines, especially on smaller non-vehicle engines that don't have ECU computers with preignition sensors, aka knock sensors.

Fuel can be a constant challenge.

All the best,

Peter