Please help - MDS engine
 

I know this topic has been beaten to death, but I would still like to clarify a few things regarding the MDS .48 FS Pro Series.
I own this engine for more than 3 years, and it is like virtually brand new because I can never get it to run right. If my memory serves me well every landing with this engine had been a deadstick landing. I was using 15% omega fuel with OS#8 plug.

I want to give this engine a try again this weekend. I did some research by searching for past posts, and people seem to suggest not using fuel with over 5% nitro. This contradicts what mds is recommending on their website (http://www.mdsengines.com). They suggest using 10~15% nitro on all their engines. (I couldn't find any info about the .48 engine though. Have they discontinued the .48?)
Finally, the most suitable glow plug for this engine is Fox w/ idle bar?

Can people with experience using this engine shed some light on this? This engine is close to brand new and I don't want to waste this powerful engine(although it has destroyed a few of my planes[:@] )
Thanks in advance!

RE: Please help - MDS engine
 

I had been reading some of the stories on here about the .48 hard to set up. And that was true for about 15 minutes, then I put a Fox Idlebar GoldPost plug in it, it was a completely different engine. I think most guys having success with them are running 5% nitro. My 2.18 makes scary noises even on 10%, the .68 and .78 are the least fussy when it comes to fuel. Both 1.48s run OK on 10% but much smoother on 5%. Minimum 20% lube. PS, my .48 runs best with a 12x5 Graupner.

RE: Please help - MDS engine
 

Many European engines MVVs etc are designed for low (5%) or no nitro since it is expensive over there it may also do ok on FAI (no nitro) just make sure its at least 18 to 20% oil may need
a hotter plug worth a try

RE: Please help - MDS engine
 

The 58, 68 and 78 do fine on 15% nitro. However, the .40 and .48 have always performed best for me when run on 10% or less. I recommend using a fox idle bar glow plug with any fuel that contains a castor/syn mix.

Before you start you engine, make sure you seal up the engine. A little silicon on the carb retaining bolt, double check o-ring on carb to make sure it is in correct location and not pinched. Remove backplate and seal with w/ a little silicon RTV. Remove head and make sure it has a head gasket-some engines I've bought new to include non-MDS brands were missing a head gasket.

Using 15% and an 8 plug is too much timing advance due to the heat range of glow plug for the amount of nitro used for this engine.

Always run your engine slightly rich. MDS engines appear to be a little more sensitive to fuel tank height and carb mixtures. With fuel tank at no more than 1/4 full, start engine, go to full throttle and set mixture so that engine is 300 rpm shy of max lean rpm. Pinch fuel line briefly and release when engine is at full throttle (PINCH TEST) after mixture needle is adjusted to ensure that engine speeds up a bit (300 rpm) and then comes back down. Shut engine down and fill fuel tank to full and start engine. Engine will be slightly richer at full throttle than was set with 1/4 tank but this tuning setup will ensure that engine does not lean out as fuel level decreases (head pressure decreases).

Always do the pinch test at full throttle before every flight to ensure you are running several hundred rpms shy of max lean rpm. You WILL BE GUARANTEED the infamous MDS deadstick if you set your mixture too lean.

Good luck and don't worry. These are great engines. BTW, make sure you put at least 30 minutes of run time on your engine with mixture just pas the 4-2 stroke point at wide open throttle before you take her up. MDS engines, unlike OS engines, are Chrome plated, and need a lot longer to break in.

RE: Please help - MDS engine
 

Thanks for all the suggestions, can't wait to try this engine again.

hobbsy,
Do you use a 12*5 prop for break in too? If not what size did you use for breaking in the engine.
I want to use a larger diameter and less pitch prop too, but I remember that all needle values and setting must be re-adjusted when changing differents size of prop. Would engines behave so different with different props?

Homebrewer,
Thanks for the comment regarding possible missing head gasket! You have saved my day when I found out that mine is missing. I would say the gasket is a must-have because it makes the fit much tigther.

RE: Please help - MDS engine
 

Yes, I decided from the git go to use the 12x5.