2-Stroke Engine Poor Performance

[threeputtpar]

Hey guys -

I have a weed whacker and an edger with small 2-stroke engines on them and have recently noticed that at WOT they are not running as well as they did before. I used to mix up my own fuel and it would take two seasons to run it all through the weed whacker, but have recently switched to 40:1 TruFuel. The poor performance has coincided with the switch, so do I have to make any adjustments when using TruFuel?

I just bought the edger this season from a pawn shop and it ran great with the gas left in it by the previous owner, but now won't run at full RPMs with the TruFuel. I figured that TruFuel would be better without the ethanol, but I'm having second thoughts. It did run wide open for 2 seconds at one point, but went back to bogging a bit and stay that way for the rest of the job. I pulled the plug and it is a nice light shade of brown, so I think the carb is adjusted correctly. I think I'll go back to mixing my own in small quantities and see what happens.

Has anyone else had these issues with TruFuel? I'd think that I wouldn't be the only one to experience this, and since it was two pieces of OPE that might take one of the variables out of the equation.

 

[4wheeldog]

My guess is that the Truefuel, being ethanol free, is providing a somewhat richer mixture, requiring that you adjust the mixture screws. Either that, or your Truefuel is old, and starting to break down. But I am betting that your little motors are just running rich.

 

[Merkava_4]

Sounds like you need to adjust your high speed mixture.

 

[mrsilv04]

Why not go back to mixing your own fuel, and simply dump the remainder of the gallon that you have at the end of the season, into your car?

Problem solved. No gas is wasted in the long run, you'll always have pre-mix that is no more than a half year old, and you won't be paying $5 for a quart of gas anymore, that seems to be giving you problems.

 

[123Saab]

Strange.

I run TruFuel 40:1 in:

4 chainsaws
2 Trimmers
1 Blower/Vac

Some I ran TF in since new, Some are older and got switched over from pump gas.

Never a problem.

Only Adjustments made were on new equipment after the first 2-3 tank fulls, A very slight tune.

I have a old Stihl 020AV Super chainsaw that screams away on TruFuel, Just loves it compared to pump gas. Love that little saw.

 

[threeputtpar]

I thought it was strange, also. Maybe I just got a bad can of 40:1 and problems will go away with my own mix. I'll give it a shot tonight.

Just thought I'd post in case anyone else was having problems.

 

[dave123]

What make of weed wacker is this? I do run VPracing SEF in all my 2stroke equipment running around 40:1 will never use anything but VP SEF anymore I just buy it by the 5gallon pail.

 

[440Magnum]

Step 1: tweak the high-speed mixture.

Step 2: check the spark arrestor screen in the muffler for clogging. The bane of 2-strokes, especially lightly-used ones.

 

[cmhj]

Some good points were made. Also make sure the exhaust ports aren't partially plugged.

 

[threeputtpar]

The weed whacker is a Yard Machines, IIRC, and the edger is a Weed Eater.

I will have to research where to find the mixture adjustments. I have very little experience with 2-strokes. I can also investigate the spark arrestor.

I just thought the timing was more than coincidental that they both started running poorly when I switched to the TruFuel.

I didn't get to mixing up any fresh fuel, and I'm going in to get snipped this Friday, so it will be a bonding weekend with the couch. Hopefully, I can look into this next week.

 

[Woody71]

I use only shell 89 in my 2-strokes and fill the red can with 1/4 Gal at a time. I also add the recommended dose of SeaFoam each time I fill up. This way I refill the can at least once a season and don't end up dumping the remainder of a gallon.

 

[97f150]

Earlier this year I switched to tru fuel from my own mixed gas. Immediatly I had to adjust both hi and low speed mixture on my Weedeater weed whacker.

After 2 cans I decided it was a waste and went back to mixing my own. I had approx 1/2 tank of tru fuel and topped it off with gas I mixed. It ran fine for approx 5 minutes, and back to adjusting I went. I also had to tweak on the first full tank of mixed. Now it runs like a top (meaning if I start it and set it on the ground, it spins around in a circle).

 

[Mike72]

The simple answer is to go back to what you were using. Different fuel/oil mixes do affect how two stroke engines perform and to a certain degree even how they sound (exhaust note). Also a carburetor adjustment may or may not be in order. I have never used Trufuel because I would need a lot of it and it costs too much versus pump price. Ethanol at 10% does not really harm a two stroke, but it does not help it either. I would use ethanol free 87 regular if it was available in my area.

 

[threeputtpar]

A quick update:

I went back to mixing my own 2-stroke fuel and the problems went away in the time it took for both engines to consume the remainder of the TruFuel in the carbs. I'm chalking this up to getting a bad batch of TruFuel, and I'll just dump the remainder in the lawn mower and use it up that way.

I bought a graduated mixing cup and will just mix the amount needed to fill the small tanks using my normal supply of non-ethanol 87 from the mower.