| Maule Operators Blog |
I bought my first Maul in 1995. It was an 1970 M-4 220 with original Razorback cover and mid time engine. I
decided I would recover it with the Poly Fiber process and have it ready to go the next spring. Two and a half
years later I finally got it in the air! First bit of advice. Don't buy a project because you think you will save
money or with the idea of making money when you sell it. Do a project if you enjoy working on airplanes. If you
want to fly. Pay a bit more, find a good sound airframe and engine, put gas in it and go flying.
So far I've owned the M-4 220, an M-5 235 that I modified to an M-6, and an MX7 160. All started out as projects.
All took longer than I thought they would to complete. In the process I've gained some experience about used
Maules and what to look for when buying. I've seen a lot of people buy a cheep airplane only to find out in a
couple of years they can't afford to maintain it in good airworthy condition. So they lose interest and sell the
airplane. Second bit of advice. It takes money to own and maintain an airplane. Be prepared for unexpected
expenses and know they are part of owning an airplane.
This seems to happen most often with engine related issues. Most of the problems can be traced back to the
engine setting around for years at a time with low usage. I'd rather buy an engine that had 1500 hrs. put on it in
the last 5 years than one that is 20 years old and only has 500 hrs. total time. When I bought the MX7-160 it had
300 hrs since overhaul, 50 hrs since tear down and inspection for prop strike, but had set 2 years without flying.
We did a annual inspection. It had great compression, low oil consumption and ran great for 80 hours. Then I
started noticing higher oil use. To make a long story short I ended up tearing the engine down, replacing the cam
and lifters, polishing the crank and honing the cylinders. The lifter faces were starting to deteriorate and little
flakes of metal were floating around in the oil grinding away on all the other engine surfaces. I had changed the
oil and cut the filter open three times and never found a thing to worry about. I'm sure if I had run it another 50
hours I would have needed a major over haul. Low engine usage equals rust equals problems.
Nov. 2010 I now have put another 100 hrs on the MX7-160. The engine has been running great. We are
working on replacing other maintenance items such as a worn throttle cable. Over all this 160 hr. stripped down
"Sportplane" should be an economical airplane to operate. I have been quite surprised with the performance. The
airplane is 250lbs. lighter than my M6. Therefore the stall speed is less so I can land slower and shorter. I have
the standard climb prop so I only cruise at 100 kts, but on climb out with me and 40 gals of fuel, 4000ft DA I get a
climb of +1000 ft/min. Take off with 180lb. pilot, 25 gals of fuel, DA 3500 ft, no wind = 350 ft ground roll.
Nov. 2011 One year and 300 hours later. I guess I shouldn't have used economical and airplane in the same
sentence. I started setting aside $25.00 per hour for maintenance needs. I later went to $35.00 and now $40.00
per hour plus $10.00 per hour engine reserve. Over the year I added extended tanks which is an upgrade not
routine maintenance but you still need to set aside money for such items. I did have to replace a cylinder because
the valve guide came lose in the head, Why? I don't know. ( 750 hrs. on a new Millenium ) Most every thing else
was general wear and tear.
Auto fuel STC I have just now completed installing the STC from Maule flight. ($1900.00 plus installation) If you
can get fuel with out ethanol it might be something to consider. Premium auto gas is running $1.25 to a $1.50 a
gallon less here at this time. I hope to pay for the expense in a year's time. The process involves removing the
Dukes boost pump and installing an electric Facet pump that runs continuously and another pump as a boost
pump. Then you cut holes in the cowling to duct outside cool air to the gascolater and engine driven fuel pump.
All to prevent vapor lock.
For some reason I am having the problem of dry carbon fouling of the plugs when using auto fuel. I'm running the
mixture as lean as I can all of the time but still get fouling. You can take an air hose and blow most of it off. It's like
a graphite powder on the plugs. I have called both Peterson and Maule and they say they have never seen this
problem. I have been running 38E plugs going to the hotter 40E has helped some. One thing that does seem to
help is running a 25% Avgas blend. It seems to clear the carbon off of the plugs. I'm going to try a 10% blend and
see how that works.
1/26/2012 I have been running a 10% to 15% avgas blend and everything is working great. At the last oil
change I checked the plugs and there was no carbon fouling.
As time goes on I will add to this rambling narrative.
decided I would recover it with the Poly Fiber process and have it ready to go the next spring. Two and a half
years later I finally got it in the air! First bit of advice. Don't buy a project because you think you will save
money or with the idea of making money when you sell it. Do a project if you enjoy working on airplanes. If you
want to fly. Pay a bit more, find a good sound airframe and engine, put gas in it and go flying.
So far I've owned the M-4 220, an M-5 235 that I modified to an M-6, and an MX7 160. All started out as projects.
All took longer than I thought they would to complete. In the process I've gained some experience about used
Maules and what to look for when buying. I've seen a lot of people buy a cheep airplane only to find out in a
couple of years they can't afford to maintain it in good airworthy condition. So they lose interest and sell the
airplane. Second bit of advice. It takes money to own and maintain an airplane. Be prepared for unexpected
expenses and know they are part of owning an airplane.
This seems to happen most often with engine related issues. Most of the problems can be traced back to the
engine setting around for years at a time with low usage. I'd rather buy an engine that had 1500 hrs. put on it in
the last 5 years than one that is 20 years old and only has 500 hrs. total time. When I bought the MX7-160 it had
300 hrs since overhaul, 50 hrs since tear down and inspection for prop strike, but had set 2 years without flying.
We did a annual inspection. It had great compression, low oil consumption and ran great for 80 hours. Then I
started noticing higher oil use. To make a long story short I ended up tearing the engine down, replacing the cam
and lifters, polishing the crank and honing the cylinders. The lifter faces were starting to deteriorate and little
flakes of metal were floating around in the oil grinding away on all the other engine surfaces. I had changed the
oil and cut the filter open three times and never found a thing to worry about. I'm sure if I had run it another 50
hours I would have needed a major over haul. Low engine usage equals rust equals problems.
Nov. 2010 I now have put another 100 hrs on the MX7-160. The engine has been running great. We are
working on replacing other maintenance items such as a worn throttle cable. Over all this 160 hr. stripped down
"Sportplane" should be an economical airplane to operate. I have been quite surprised with the performance. The
airplane is 250lbs. lighter than my M6. Therefore the stall speed is less so I can land slower and shorter. I have
the standard climb prop so I only cruise at 100 kts, but on climb out with me and 40 gals of fuel, 4000ft DA I get a
climb of +1000 ft/min. Take off with 180lb. pilot, 25 gals of fuel, DA 3500 ft, no wind = 350 ft ground roll.
Nov. 2011 One year and 300 hours later. I guess I shouldn't have used economical and airplane in the same
sentence. I started setting aside $25.00 per hour for maintenance needs. I later went to $35.00 and now $40.00
per hour plus $10.00 per hour engine reserve. Over the year I added extended tanks which is an upgrade not
routine maintenance but you still need to set aside money for such items. I did have to replace a cylinder because
the valve guide came lose in the head, Why? I don't know. ( 750 hrs. on a new Millenium ) Most every thing else
was general wear and tear.
Auto fuel STC I have just now completed installing the STC from Maule flight. ($1900.00 plus installation) If you
can get fuel with out ethanol it might be something to consider. Premium auto gas is running $1.25 to a $1.50 a
gallon less here at this time. I hope to pay for the expense in a year's time. The process involves removing the
Dukes boost pump and installing an electric Facet pump that runs continuously and another pump as a boost
pump. Then you cut holes in the cowling to duct outside cool air to the gascolater and engine driven fuel pump.
All to prevent vapor lock.
For some reason I am having the problem of dry carbon fouling of the plugs when using auto fuel. I'm running the
mixture as lean as I can all of the time but still get fouling. You can take an air hose and blow most of it off. It's like
a graphite powder on the plugs. I have called both Peterson and Maule and they say they have never seen this
problem. I have been running 38E plugs going to the hotter 40E has helped some. One thing that does seem to
help is running a 25% Avgas blend. It seems to clear the carbon off of the plugs. I'm going to try a 10% blend and
see how that works.
1/26/2012 I have been running a 10% to 15% avgas blend and everything is working great. At the last oil
change I checked the plugs and there was no carbon fouling.
As time goes on I will add to this rambling narrative.
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