912 ULS will not maintain full power

[bitten192]

2007 REMOS G3/600 Rotax 912ULS 750 hrs on the engine, 60 hrs on plugs

Engine will not develop full power.

I went on cross a country over the mountains, engine worked great. Got home, put in 10 gallons auto gas from local gas station that we always use. 92 octane no ethanol.

 

Next day did a normal run up, engine would not go above 4200 rpm.

 

Drained some fuel. No water, gas looked good (a little blue from previous 100LL fill up before the 10 gallons of auto fuel)

 

Replaced throttle cables, replaced carb return springs, replaced fuel filter, and balanced the carbs.

 

Normal run up. developed 5000 rpm+ on the ground. Took off, and at about 300 feet AGL there was an abrupt drop in engine rpm to 4200 rpm at full throttle. I Landed.

 

On the ground I shut down the engine, I let it sit for a minute with the electric fuel pump on. Started up, normal run up, developed 5000 rpm+ on the ground, but after brief taxi it would only go to 4200 rpm.

 

HELP. What say you Roger? Bad gas (not likely)? Bad float?

EGTs are about balanced. Maybe 100 degrees hotter on right front.

[FastEddieB]

Not Roger, but pull your float bowls, looking for debris, and look up into the main jet as a first step.

[Roger Lee]

I'm with Eddie, pull the carb bowls. The symptoms makes it sound like debris. While the bowls are off put a rag under each open carb bowl area and open the fuel valve and let just a little bit of fuel run out. After you replace the bowls make sure the throttle on each carb opens fully 2-3 times and together.

[bitten192]

OK I'll give it a try. A guy in the UK on the Rotax forum has the exact problem. International gremlins.

[bitten192]

Cleaned both carb bowls, flushed fuel line from tank to fuel distributor block, drained and refilled gas tank. Problem corrected. Went flying 20 minutes at full and cruise power.

[Anticept]

I suggest getting a MrFunnel, the F15 model (also known as AF15CB). We have three of them, one for each airplane. They work absolutely fantastically and keep debris out.

[bitten192]

Thanks. I tried one. The gas hole is on the side of the fuselage so the funnel doesn't work very well, I'm going to try to modify it so I can use it on the REMOS.

[Anticept]

filter it in to the gas can at the pump.

[GravityKnight]

I suggest getting a MrFunnel, the F15 model (also known as AF15CB). We have three of them, one for each airplane. They work absolutely fantastically and keep debris out.

 

I have a couple of these as well.... when you read it won't let water pass, and then look at it.. you kind of say, that's some BS... poor some water in and not a drop comes out!!   

 

But it is a nice solution to keep crap/water out of the fuel, my only complaint is that on both the smaller one, and the large one I have, the filtering screen doesn't go all the way to the bottom of the inside of the funnel, so it always leaves a little fuel behind in the funnel itself. Otherwise these are awesome.

[FlyingMonkey]

I have a couple of these as well.... when you read it won't let water pass, and then look at it.. you kind of say, that's some BS... poor some water in and not a drop comes out!!   

 

But it is a nice solution to keep crap/water out of the fuel, my only complaint is that on both the smaller one, and the large one I have, the filtering screen doesn't go all the way to the bottom of the inside of the funnel, so it always leaves a little fuel behind in the funnel itself. Otherwise these are awesome.

 

That probably helps filtration.  Any debris or sediment heavier than gas is trapped below the filter line.

[Anticept]

I have a couple of these as well.... when you read it won't let water pass, and then look at it.. you kind of say, that's some BS... poor some water in and not a drop comes out!!

 

But it is a nice solution to keep crap/water out of the fuel, my only complaint is that on both the smaller one, and the large one I have, the filtering screen doesn't go all the way to the bottom of the inside of the funnel, so it always leaves a little fuel behind in the funnel itself. Otherwise these are awesome.

As morden said, the sump is by design. just pour it into a separate container for refiltering later.