Weedwacker and lawn mower issues after filling with 91 octane gas.

[jtvang125]

May very well be just a coincidence but after refilling the weedwacker with 91 octane gas from the canister I refilled while topping off my car, I'm have difficulty starting it. It started and ran for 3 secs or so and stalled. It never started again after that and I tried til my arms were numb.

Gave up and tried the lawn mower. There was still gas inside but I topped it off too. It'll start but sputter really bad like it's going to stall and eventually does after about 30 seconds. It also blows out black smoke. The gas was quite old and I should have probably drained it before refilling.

These two are fairly new and I never had this much trouble trying to start them?

 

[MagnusTheBrewer]

Higher octane in engines not designed for it is a bad idea. It leads to gunked up engines and exactly the type of symptoms you mentioned. Drain or syphon the gas and put some new lower octane fuel in and you should be good to go.

 

[RLGL]

When you fill your can add Stabil to the fuel as per the directions on the bottle. Also would not hurt if you added Yamaha's Ring Free or Mercury Marine's Quikkleen to the mixture. Both are a detergent that will remove carbon, an added benefit they will also clean the fuel system. Follow directions on the container the products come in.
DO NOT use Seafoam!!!

 

[jlee]

Is your weedwacker supposed to take pre-mixed fuel?

 

[Meghan54]

Higher octane in engines not designed for it is a bad idea. It leads to gunked up engines and exactly the type of symptoms you mentioned. Drain or syphon the gas and put some new lower octane fuel in and you should be good to go.

I'd first ascertain the make, model, and year of the equipment in question before making such a blanket statement of using lower octane gas. For instance, both Stihl and Echo have been requiring a min. of 89 octane gas in their equipment for over a decade.....just sayin'.

 

[Rifter]

are you sure the weed wacker is a 4 stroke not a 2 stroke?

 

[jtvang125]

Higher octane in engines not designed for it is a bad idea. It leads to gunked up engines and exactly the type of symptoms you mentioned. Drain or syphon the gas and put some new lower octane fuel in and you should be good to go.

I looked through the manual and it says nothing about needing regular gas, just that it needs to be atleast 87 and no more than 10% ethanol. It might be due for a new spark plug so I'll pick one up, drain the gas and and try again.

 

[mindless1]

Higher octane in engines not designed for it is a bad idea. It leads to gunked up engines and exactly the type of symptoms you mentioned. Drain or syphon the gas and put some new lower octane fuel in and you should be good to go.

Nonsense. At worst it will retard detonation and you'd have less power. Draining gas, if it helps would be a sign that it was just bad gas, not the octane at a mere 91.

It's a coincidence. You have two pieces of equipment that need (most likely) carb cleaning or rebuild. Spark plug, sure it might help a tiny bit but is not much of a factor until several years old (you did not mention make, model, age, hours on this equipment ?).

9 times out of 10, you need to clean and/or rebuild the carb. On 2 cycle equipment, also check the fuel line for cracks, primer bulb.

 

[WilliamM2]

Did both these items sit all winter without Stabil? May need to clean the carbs. And as asked before, did you mix 2 stroke oil in the weed wacker?

 

[olds]

What was the ethanol content of the fuel? It wouldn't hurt anything that quickly but it will over time.

http://www.ethanolrfa.org/2016/04/ama-continues-fight-against-ethanol/

 

[Meghan54]

What was the ethanol content of the fuel? It wouldn't hurt anything that quickly but it will over time.

http://www.ethanolrfa.org/2016/04/ama-continues-fight-against-ethanol/

First, no one is talking about E15. And how much time does it take to make a difference? 5 years? 10 years? I'm interested....mostly because I've got an assortment of 2-stroke and 4-stroke power equip. that's used ethanol-laced gas for years without incident.

 

[C1]

There's an outside chance that you got water in the tank, either due to bad fuel that was recently added or on account of phase separation of the fuel that had been sitting in the tank. This would be especially the case with an ethanol additive fuel.

I would pour out the fuel tanks on both engines, clear the fuel lines and carbs of old fuel, remove & clear the spark plug then retry each machine using ethanol free fuel purchased from Lowes or Home Depot.

If your going to leave fuel sitting in the tanks unused for months on end, then use ethanol free as, besides being hygroscopic, ethanol fuels are corrosive and can damage fuel tank internal anti-corrosion coatings.

 

[RLGL]

Everyone is forgetting one thing, the fuel quality varies across the country. I have talked to others in the marine business and heard horror stories about the fuel. In my area things have been pretty good over the years.