Mt 57..... Runs like crap
 

Just got around to installing a new mt57 in a plane. Engine was purchased early Dec. 08.
Engine starts and idles great but anything above idle and it miss-fires like crazy. Am running stock exhaust, menz 23/8, peak rpm about 6600. Have tried running remote pressure line into fuselage...no change. Tried every needle setting possible, still miss-fires. Have 7 flights on it and some ground tuning, about a gallon of fuel. Its acted the same way since the beginning.The engine runs the same on the ground or in the air, cowl on or cowl off. I Guess the problem is in the ignition system but i don't know. It runs nothing like the ones in the you-tube videos.

I bought this from the U.S. distributor, [email protected]...... anyone have any ideas on what's going on with this engine....... or knows who is performing warranty work on this engine.

RE: Mt 57..... Runs like crap
 

Sounds like an ignition problem.

RE: Mt 57..... Runs like crap
 

 Reduce spark plug gap to  .016 - just  to see.</p>

  also make  darn certain the battery used  has good connection and is  up to snuff.</p>

RE: Mt 57..... Runs like crap
 

I would go buy a new sparkplug.</p>

RE: Mt 57..... Runs like crap
 

outssider,</p>

MT warranty work is handled out of their Florida office, www.MTEnginesusa.com.  They have been noted for responsive customer service, so try them if Larry can't help you.</p>

A flaky ignition can cause some weird behaviour; I've had one RCExel on a different brand replaced under warranty, with much better results than I expected.  It can definitely affect top end rpm &amp; power if it's even a little marginal.</p>

In addition to checking your battery and plug gap as Dick suggests, you might try using a different switch between the battery and the ignition as an experiment.  Also the spark plug cap takes pretty firm pressure to seat properly and I've had trouble with those before.  One other thing, is the magnet for the ignition sensor passing fully under the sensor?  I've seen a case where the sensor couldn't get a reliable reading on the magnet because it wasn't properly aligned.</p>

Good Luck!</p>

 </p>

RE: Mt 57..... Runs like crap
 

A "whacky" sensor will also drive you nuts. Sometimes they fail completely and then the engine won't run, but sometimes they just misfire making you think it is the plug or possibly the ignition box itself. Terry at CH Ignitions says they fail in the "whacky" mode about 5 percent of the time. I have also had them go bad if they had gasoline dripped on them for a bit; like from a leaky seal.</p>

AV8TOR</p>

RE: Mt 57..... Runs like crap
 

thanks for the help everyone....


I have a spare newplug and i'll give ita try although the odds of a brand new plug being bad is slim.
ignition battery is new4 cell and it's checking out fine. ignition switch is new also but i will bypass just to be sure. Didn't think about the alignment of the magnet so will check that also......the engine starts and idles great...no missing at all at idle....full throttle is not too bad either only little miss....but everything inbetween is terrible...

Tommy has already offered to send out a new ignition so will try that when it arrives too.

boot sets down on plug very tightly...good contact with ground...

RE: Mt 57..... Runs like crap
 

I think you have found that Tomy Shen is about the most "customer aware" manufacturer around. Tomy wants everyone to be happy with his products and will support you until the problem is corrected.

Cheers,

Hose A

http://www.rcuniverse.com/forum/js/f...sn/biggrin.gif

RE: Mt 57..... Runs like crap
 

if the plate in the back move is goin to do that,check the back and gasquet

RE: Mt 57..... Runs like crap
 

I tried a 5 cell 6v pack and new plug, also by-passed ignition switch. No change. i don't think it's the ignition because it will sometimes run full throttle or 3/4 throttle without missing much or even at all. It's the lower rpm range that has a lot of gurgling/missing. Maybe miss fire is not the exact word.Perhaps itcould be something in the reed block area causing the problem. I checked the sensor and it seems to line up with the magnet.
</p>

I listened today to some you-tube videos ofother peoplesmt57. Mine does not run anywhere nearas smooth as the ones on the videos.



</p>

</p>

RE: Mt 57..... Runs like crap
 

Check the gasket between the case halves. Some have been known to blow out and leak are if the case screws come loose if not held when tightening the standoffs.

RE: Mt 57..... Runs like crap
 

WOW! Sounds like you've tried just about everything.

If possible, see if the reeds are sitting flat against the reed block. Mine were off a bit on one side due to the screws that hold them on causing some small amount of lift. A few passes over a peice of wet and dry on plate glass and the reeds are sitting flat for a good seal. I sanded the reed block flat. You may be fine, but seems like it would be worth a check.

Good luck.

RE: Mt 57..... Runs like crap
 

the gasket looks good, i made sure the casebolts were tight before screwing on the standoffs.





I will look at the reeds and the reed block today.....thanks...

what was the symptoms of your engine before you made this repair.....

RE: Mt 57..... Runs like crap
 

Um, well my engine arrived with some assembly required. I took the opportunity to clean out all the shipping debris and since the carb was not attached, had a good look at how things were there too.

Sorry, I neverfound outhow it would run if I had left it as is. Just thought since you mentioned it, I would let you know it is a good thing to check out for sure.

My guess, is that with one or both reeds not allowed to completely close would cause the engine to run like crap http://www.rcuniverse.com/forum/js/f...sn/biggrin.gif
Seems like there might be some blow back if a reed was not closing. Do you notice any fuel spray behind the carb?

Keep us posted. I'm sure you'll love this engine once it gets sorted out..

RE: Mt 57..... Runs like crap
 

here's what i found, one reed is chipped and is raised up a little less than 1/32". The chip however doesn't look big enough to affect the seal....i have no idea if this could cause the problems I'm having or not.
I didn't notice any unusual discharge out of carburetor

RE: Mt 57..... Runs like crap
 

Looks like you may have found your problem.  THe reeds have to seal.

RE: Mt 57..... Runs like crap
 

Did you check the timing?

RE: Mt 57..... Runs like crap
 

no i didn't check the timing but i did take the sensor off to inspect it, i put it back in the exact same location. I did notice that the sensor only will adjust at the most an eight of an inch. it starts and idles great....

tommy has already sent me (have not received yet) a module. He tells me he will send out some reeds but it would be faster if i bought some milar or fiberglass and madeit myself...http://www.rcuniverse.com/forum/js/f...used_smile.gif


but where do i get this material........

RE: Mt 57..... Runs like crap
 

<div style="margin: 0in 0in 0pt"><span style="font-size: 9pt">Timing is easy to check and since your engine is acting up from the beginning, I think it&rsquo;s worth it. I'm not sure if you have seen this post: http://www.rcuniverse.com/forum/fb.asp?m=7512885</span></div>

RE: Mt 57..... Runs like crap
 

You've done everything, it's hooped, send it to me!

Love mine!</p>

RE: Mt 57..... Runs like crap
 

I believe they fixed this timing issue in a latter version, mine was purchased after the fix. besides, i'm getting 6600-6700 rpm on a 23/8...same as this guy after his fix. rpm isn't the real issue.


hughs500e

i'll send you mine if you send me yours...

RE: Mt 57..... Runs like crap
 

Tommy wants me to try elongating the holes in the sensor and advancing the timing....will give this a shot next....says the chip in the reed is not bad enough to cause theproblem.

RE: Mt 57..... Runs like crap
 

I used 800 wet/dry with a good flat plate glass and honed my reed block down very evenly. </p>

Since you have it off, I hope you will too. Mine was pretty much flat, except where the screws went through to hold the reed on. </p>

Agreed the chip is probably not too much of an issue. I could not get the photos to open up. It just said Loading. </p>

Personally, I'd be hesitant to run it with a damaged reed, but Tomy is a good guy, he will get dialed in.</p>

RE: Mt 57..... Runs like crap
 

Order a new reed. Cutting your own requires that they be cut in a punch type method, not freehand with scissors or a knife. They will fray if cut free hand.

RE: Mt 57..... Runs like crap
 

Hey Outsider-

Just out of curiosity, did you print out that timing wheel from CH's website and check your timing?