franchi

Hello:

What are your thoughts, advice, and experiences with this engine? Is it worth fussing with or is it a piece of trash or treasure ?

I have a new one and would like to know if it is a worthy sport engine.

Tia,

Franchi

franchi

Marz 2.5 opinions?

pe reivers

Impatient?

raglafart

My Feedback: (10)

You've already asked this question about 2 pages back.
The general consensus is that they are for the money not a bad engine. They don't lack power.
If handled with respect they can provide a well worth while sport engine.
The shafts are the weak spot and it's not uncommon to hear of breakages.
Rough handling, ie crashes can bring this about or running on too big a prop and overcompression can lead to shaft failures too.
There have been posts about tempering back the shafts to minimize the possibility, I'd just run it and have fun with it.
The shaft is the only issue I'm aware of

earlwb

It depends if if you have a good one or not. Some work Ok others not so good and still some really run great. They used to make the engines at maybe a dozen or more different locations inside Russia at the time. So the engines vary from one locale to another and as to whom was making them at the time too. Adrian Duncan of Model engine news discussed them here too http://modelenginenews.org/ad/marz.html

You will likely need to replace the main bearings with better ones, replace the screws with better ones. Since there are only three screws holding the cylinder head on, this is important as the screws could break. Some people stabilize the crankshaft by heating it to 500 degrees and letting it cool slowly. They have been known to break crankshafts before.

Here is one of mine being limbered up:

franchi

Hi All:

No, I am not impatient, When I hit the spell checker, it erased both of my messages.

The spell checker did not work for this site! Thus the two posts!

I searched Mars 2.5 engine but I did not find what I was looking for. I will go back manualy to previous pages to see my orginal question.

Thanks for all of the help,

Franchi

Recycled Flyer

I don't understand, when I do a search for "Marz diesel franchi" I get at 9 threads on the first page with you saying that the Marz is 'quite good'.

Surely this has been answered (as in commented on) quite well before?

This is the same question from as far  back as 2008 -
http://www.rcuniverse.com/forum/m_79...tm.htm#7943872

raglafart

My Feedback: (10)

Not being critical, but you asked exactly the same question on this thread; [link]http://www.rcuniverse.com/forum/m_11436133/tm.htm[/link]

franchi

Hi:

I have no idea as to how I could not get any results when I searched this question. That is why I asked the same question again.

In any case, I was given a new Marz 2.5 and a gallon of Davis fuel recently. I was planning to get rid of my Diesel engines when my currant supply of fuew had been exhausted but now I will continue to play with the Diesels that I have in my posession.

Once again the Marez piqued my interest. Thus the question.

Since I had a bad first experience with the Marz 2.5 I can see no reason to go through that agony again. Lol

What I do have to play with are the following:

ST G20/15D with new chrome job

O.S LA with Davis head

O.S. FP with Davis head

MVVS D7

Fox .15 With Davis head

OK Cub .075 (2)

StT G/21.35 with A Davis head

I have an airplane built for each of these engines and they are ready to fly. The above engines save the OK .075 are great running engines! I have had good luck with them! It is just the fuel cost that botheres me!


Due to the high cost of fuel, I will be getting rid of these engines in the future.

Stay well,

Franchi

Recycled Flyer

Hi Franchi,
just go to the top right of this page and seek out the horizontal beige colored boxes marked "FAQ, NEW POSTS, MEMBER LIST, SEARCH......."
Click on "SEARCH", type in some key words e.g.'Marz diesel' then click the 'GO' button on the right of the field that you just typed your key words in and every post that contains those key words will be listed when the page refreshes.

Then simply click on one of the listed phrases blue headings to go to that thread. Hit the back arrow on the header bar near the web address to retrace your steps and choose another loaded search topic.

If there proves to be a problem then please get back to us mate.

Cheers.

maxtenet

High cost of fuel? Hell, a gallon costs less than a decent bottle of wine and lasts a whole lot longer. The Marz is a perfectly acceptable engine and for 30 bucks, if it breaks, throw it away. Cut back on other luxuries like food or gas for your car and you'll be fine.

Max

gcb

I have two, one with a black muff and one with an aluminum muff. The one with an aluminum muff had "binding" problems. I fixed it by using a thicker rear gasket and polishing around the rotor some.

Starting instructions said to screw down the contra until it reaches the piston at TDC, then back off a turn. It worked. The engine had almost no compression from new but as it broke-in the compression seal formed and it gained compression and also became easy starting. I gave it about 10 full-speed two minute runs, each followed by complete cool down. Runs fine, decent runner. Since it is a short stroke engine I do not use larger than a 9x4 on it. So far, so good. I don't yet have a lot of run time.

Good luck with yours.

George

AMB

George looks like you played Russian roulette and you won martin

gcb

Thumbs up...I like that type of humor!

George

fiery

My Feedback: (2)

Another engine from the people who made the MARZ 2.5, the MK-12B.

ffkiwi

I had no idea they were still making them as late as that, fiery-considering the Webra Mach-1, of which the MK-12B is a fairly close copy, first appeared in 1953..........and had faded away by the late 1950s or very early 1960s, pending the advent of the Mach-2 in 63 or 64........shades of the Indians making copies of the Morris Oxford III 50 years after it was introduced....

ChrisM
'ffkiwi'

fiery

My Feedback: (2)

I was suprised at the build date also.

The whimsical box artwork contrasts nicely with the utilitarian looking peice of machinery. The parts fit and inside finish of the MK-12B shown is nice enough.

When I saw the pre-printed price on the box I smiled. Eight roubles. Sold complete with a detailed hand book / operation manual revision 12.11.81 (except I can't read cyrillic), combi-tool for the prop nut, spray bar nut, and cylinder, comprehensive mounting hardware in heavy waxed paper; and a peice of (now ossified) white translucent fuel pipe.

Try buying one for that price now .

DerFly

Hi Fiery,

I have that exact MK12B also new in box in much the same state as yours. The needle valve cup on mine is crimped on too "long" and the contra is tight as all bug, I mean tight as all get out,!of course.

I think mine is of similar vintage, 83 from memory as its packed away.

I believe the FAI free flight helicopter altitude record was powered by one of these.
Agreed that workmanship looks quite OK on these.

Have you run yours yet?

Regards,
DF

franchi

Hi All:

Thanks Mate for the help concerning searching a topic. I did this but came up with nothing. I will try again.

I had a MARZ 2.5 cc awhile back and when I thought the it was broken in enough to be flown, it self destructed! This was on the test stand with a Cocx 8X4 gray prop! The cylinder case split in the front for about 170 degrees. Up until then, it was a fine running engine! It broke my heart as it was so easy to start. I did enjoy the rear N.V.A. as it was away from the prop!

Where can I buy one of these for $30.00? At that price, they would be a great buy!

Enough for now,

Franchi

maxtenet

Actually 35 bucks!


https://shop.mecoa.com/shopdisplaypr..._md.asp?id=203

Max

franchi

Notice that they are SOLD OUT.

maxtenet

Oh yeah! Sorry!

Recycled Flyer

Try here -
http://carlsonengineimports.net/SPECIALS.html

franchi

G'Day:

There was one on E BAy for $28.00 plus $8.00 shipping and it ended with NO bids. What does that indicate?

Franchi

Recycled Flyer

That no one needs an extra one?