Buying M-7-235C with options

[Pbfl510]

Good evening all,

I am new to this site. Never owned an airplane before.

Came across a M-7-235C (1999) for a good price.

The engine needs to be replaced. Debating on replacing it with the original O-540 or upgrade it to the IO-540. Waiting on quote.

Thoughts?

Anybody knows of an excellent Maule instructor in the Houston area?

Thank you for your input.

PB

[chris erasmus]

I am partial to the O540B4B5 engines, they are bullet proof, mine takes a lot of abuse and keeps on ticking

[TomD]

I am partial to the O540B4B5 engines, they are bullet proof, mine takes a lot of abuse and keeps on ticking

If I am not mistaken, they also are the only 540 with an Autogas STC.

TD

[Mountain Doctor]

I believe that to be correct, Tom.

I consider the ability to burn car gas a benefit for a bush
plane. Not to mention the cost savings.

In a pinch the plane would even fly withouth the paperwork . Even a little alcohol, although not great for the seals etc. in the long run won't hurt anything in the short run.

Car gas also much cheaper of course. I won't open the debate as to whether or not it is better for your engine or not.

Carbs usually easier to start, especially when hot.

The O engine is cheaper than the IO, and a little lighter I think.

Lycomings usually don't form much carb ice.

The IO is a little smoother, and with balanced injectiors can be run LOP and save about 2 GPH.

I like IO's, but the O's have advantages too.

[chris erasmus]

Spot on the b4b5 runs on car fuel without a problem. Due to the shortage and extreme cost of avgas in SA I run mine almost exclusively on car fuel. Never had a problem.

[Kirk]

True on the B4B5 being the only 540 approved for auto fuel, with some mods like added fuel boost pump.
I have the O540J1A5D which is the lightest weight 235 hp, by virtue of the much maligned single drive dual magneto.
I would favor an injected engine for fuel economy and smooth running. But the big factor is; do you have a useable core? If you have the previous engine, you will probably find it far more economical to rebuild what you have.

Just my 2 cents worth

Kirk

[captnkirk]

the paper work alone is enough to end the idea of switching to the IO look at an electronic ignition system a lot easier and better fuel burns from what i've read I'm sure Jim or Jeremy will have better info.

[gbarrier]

My bird began life with an 0 engine. It was later converted to I0. I'm away from home and logbooks but as best I remember only a logbook entry was made. Might have something to do with both engine being on the TDC. That said I bet fuel pumps and various accessories are different so some cost there.

[MauleMechanic]

IO-540 has a different cowling

[MauleMechanic]

Hand propping an IO is almost impossible

[chris erasmus]

You can change pistons and couterweights in the O540 B4B5 and up the HP to 250 and stil remain car fuel compatible, very handy when you flying hot and high conditions. Not very legal but do able

[chris erasmus]

You can always take the engine port it flow it balance blueprint and do the exhaust and gain a few more horses

[Victor Gennaro]

I have a M-7 235C with a carb. I love it! Runs great I fly in cold temps alot, it starts well and use the carb heat without trouble. Our club had an injected C 172 before and starting was a pain, esp when hot. Simple is better and the 235 has plenty of power even on hot days.

[Pbfl510]

All,
Thank you for the inputs. I will stay with the good old straight O-540 for simplicity, price and the fact that I could hand prop it someday if needed.

Cheers,

[MauleMechanic]

Smoothest running engines I ever experienced in the Maule is the B4B5