Glass type fuel filters - Please take note
Posted: Wed Nov 08, 2006 8:51 pm
Alright guys and dolls....listen up and pay attention.
After reading John's last post regarding the glass type fuel filter, I thought I had better obtain some unbiased opinion. After consulting with my friends in the USA, who, by the way are some of the most well known and well respected Rotax servicemen over there, I have come to the conclusion that even though some, or most of us, have never had a problem with the glass type fuel filter, we better take note of the fact that there is definitely something not too lekker with these things.
Here is what Mark Smith had to say:
"There is always something different that attracts some folks attention.
The Pteradactyl was once said to fly really bad, and it did so with full personal knowledge.
But some folks love it even though they may admit, or not, that it does
indeed fly badly.
Same with this glass filter.......It sounds good, replaceable element, cleanable, etc,
but it is bad news in my opinion.
A friend bought a used Rans S9, nice little thing but a bit underpowered with a 503.....
His first attempt at flight could have been a total of the plane as the
engine quit at a most inopportune time.........
he made it down in a sloped field across the road........
The filter was fully plugged and I tested it with a can of fuel and
gravity flow.....very small trickle at best.
I have seen other examples of this filter where they have come apart
inside and leaked, etc,
the best is a cheap, 2 dollars or so, paper filter to be replaced every
100 hours......it is clear to see major crud, and it will also show water if it gets that far,
my Quicksilver types have a loop of fuel line and two low points that connect with it, this traps any water for the most part,
I have removed many of the glass fliters from customer's planes and have a good reputation for continued good performance using the small paper pastic filters......
hope this helps...."
AND
This is what Brian McCallen had to say:
"Never heard of any problems with the Rotax engines on aircraft here in the states but I have heard of problems on snowmobiles. The problem was not that the filters were so fine that any they would clog up easy. The problem was the filter screen was so fine and the fuel consumption so high the filters would restrict the fuel flow. That may be the reason some of the microlighters are able to restart the engine after they successfully do their dead stick landing.
Now we have had problems with the paper type filters also restricting fuel flow when there is water in the fuel the paper will swell up and restrict fuel flow.
Now I noticed some of the microlighters say they have never had a problem. It could be in the way the fuel system is installed on that particular aircraft. If the fuel pump is located much higher than the fuel tank this may not allow the fuel pump to draw enough fuel through the filter to keep up with the engine demand because it is already working hard to just draw the fuel from the tank. Maybe their fuel pump does not need to work as hard to supply the required fuel at the higher RPM's because of where it is located in the system.
Just my opinion."
So, there you have it.......you can draw your own conclusions from the above.
Let it be known that the Duck has moved closer to the John Young camp of thought but will reserve judgement until further investigation........
After reading John's last post regarding the glass type fuel filter, I thought I had better obtain some unbiased opinion. After consulting with my friends in the USA, who, by the way are some of the most well known and well respected Rotax servicemen over there, I have come to the conclusion that even though some, or most of us, have never had a problem with the glass type fuel filter, we better take note of the fact that there is definitely something not too lekker with these things.
Here is what Mark Smith had to say:
"There is always something different that attracts some folks attention.
The Pteradactyl was once said to fly really bad, and it did so with full personal knowledge.
But some folks love it even though they may admit, or not, that it does
indeed fly badly.
Same with this glass filter.......It sounds good, replaceable element, cleanable, etc,
but it is bad news in my opinion.
A friend bought a used Rans S9, nice little thing but a bit underpowered with a 503.....
His first attempt at flight could have been a total of the plane as the
engine quit at a most inopportune time.........
he made it down in a sloped field across the road........
The filter was fully plugged and I tested it with a can of fuel and
gravity flow.....very small trickle at best.
I have seen other examples of this filter where they have come apart
inside and leaked, etc,
the best is a cheap, 2 dollars or so, paper filter to be replaced every
100 hours......it is clear to see major crud, and it will also show water if it gets that far,
my Quicksilver types have a loop of fuel line and two low points that connect with it, this traps any water for the most part,
I have removed many of the glass fliters from customer's planes and have a good reputation for continued good performance using the small paper pastic filters......
hope this helps...."
AND
This is what Brian McCallen had to say:
"Never heard of any problems with the Rotax engines on aircraft here in the states but I have heard of problems on snowmobiles. The problem was not that the filters were so fine that any they would clog up easy. The problem was the filter screen was so fine and the fuel consumption so high the filters would restrict the fuel flow. That may be the reason some of the microlighters are able to restart the engine after they successfully do their dead stick landing.
Now we have had problems with the paper type filters also restricting fuel flow when there is water in the fuel the paper will swell up and restrict fuel flow.
Now I noticed some of the microlighters say they have never had a problem. It could be in the way the fuel system is installed on that particular aircraft. If the fuel pump is located much higher than the fuel tank this may not allow the fuel pump to draw enough fuel through the filter to keep up with the engine demand because it is already working hard to just draw the fuel from the tank. Maybe their fuel pump does not need to work as hard to supply the required fuel at the higher RPM's because of where it is located in the system.
Just my opinion."
So, there you have it.......you can draw your own conclusions from the above.
Let it be known that the Duck has moved closer to the John Young camp of thought but will reserve judgement until further investigation........
the swollen filter will starve the already dead engine of fuel.
