Turk1

That click is very normal.Check your fuel lines for delivering proper fuel to carb.Check your glow plug.

wyo69cowboy

My Feedback: (2)

My .53 also had the click sound, and was very tight when I first got it. Ran fine after break-in; I'm gonna try to the carb notch, however, as I still wasn't getting a great transition.

jib

The click is good. I believe it's the con rod compressing and flipping over from the BTDC (Before Top Dead Center) to ATDC (After Top Dead Center) due to the tight fit at the top of the piston travel. Run that engine for 10 minutes and there will be a lot less resistance at the top of the travel.

jack

capuleen

I have felt this click sound on any glow engines with no rings I have ever owned and it would go away as the motor is braking in just be patiant and run it very rich on several tanks and follow your owner manual. I am sure it be just fine and have a good flight.

ScottMcM

My Feedback: (66)

UPDATE....I ordered two Super Tigre carbs for the Aviastar 46's. Put them on, and the engines ran great....finally I've got this situation under control.....WRONG!! I was syncing (sp?) the engines on the Cessna 310 this morning. I cranked one engine, and tuned it just a tad rich off of peak rpm. I shut it down, and did the second engine the same way. I restarted both engines, and used my mixing on my radio to sync the rpms through the entire range. I had just finished syncing the engines, and was rechecking to make sure that they were in sync throughout the entire range, when the port engine went from 11,000 rpm to zero in a fraction of a second. The connecting rod let go. It looks like it got so hot it melted. I took a photo of the results. Sorry for the poor quality, but it was from my cell phone camera. Anyway, you get the idea. Both engines were broken in according to the instructions. I was running 5% omega, with 3 oz extra castor per gallon, and a Master airscrew 10x6 prop. Was turning around 11,000 rpm on both engines. Well, I've made my decision on the Aviastar engines....A BIG FAT NAY!

MartyH

My Feedback: (16)

Well, my Aviastar 46 showed up in the mail today. externally it's a very good looking piece and I can't wait to try it. As others have mentioned, the pinch is tight!

bigedmustafa

My Feedback: (2)

That's too bad, ScottMcM. It's got to be frustrating putting that kind of time and effort into getting a pair of engines running only to have one break like that.

w8ye

My Feedback: (16)

I've seen this happen to the best of brands.

A local kid had two new Enya SS40BB's do this

ScottMcM

My Feedback: (66)

Any ideas as to what caused it?

w8ye

My Feedback: (16)

On the Enya's the rod failed immediately, they replaced the rod and the new rod failed. Then MRC replaced the whole engine and no more problems.

We figured the cylinder bore was not square with the crankshaft

Star7

There has been commentary that the 'pinch' is so extreme on some of the Chinese motors that failure to get them up to temp quickly on the first run is overstressing the rod at the crank pin. That sounds like hand waving to me, but my first run on my aviastar featured a heat gun to prewarm it......I have two gallons through it now and it runs well. I only used the heat gun on the first run and got it two stroking right away. I did the same on a JBA 56 and both were easily hand started on the second tank. Personally, I think that you just caught a random flaw...sorry for your trouble.

wyo69cowboy

My Feedback: (2)

FYI, the carb from my OS50FSR fits. I didn't measure the throats with my caliper, but the OS carb throat O.D. is the tiniest bit smaller; i.e. it fits just a tiny bit loose in the case, but the pinch bolt and O-ring seem to tighten it up just fine. If the weather is decent this weekend, I may try running both the Sig carb again and the OS to see any differences.

MetallicaJunkie

These definitely arent beginners engines...... most beginners dont have spare carbs lying around or know how to tinker with engines.

jag215

I know this is an old thread, but I am having a problem with my .53 and I need some help. It was running o.k., but the head was leaking fuel. I sent it in to sig and they repaired the head. Today I tried to fly it again and it did'nt go so well. Nothing serious, (a few dead stick landings), It would idle and with some adjustment go to full throttle. I was flying and tried to land and I decided to do a go around and it would sputter out when I advanced the throttle and the engine would quit(twice!). It isn't transitioning to full throttle from idle with any consistency. I messed with the needle valve for a while and called it a day before I ruined my plane. My question, What carb. from another company will fit my aviastar .53? It seems other people are having a better experience by changing the carb on these engines to get them to run more reliable. I'd rather order a new carb. than fly like I was today. It's on a LT-40 with an 11x6 prop.

ScottMcM

My Feedback: (66)

A Super Tigre carb fits perfectly on the .46, but I don't know about the 53. I was able to modify the carb on one of my .46's, and it performed much better. Pretty simple mod. All I did was /dremel (grind) the opening on the carb barrel. It took less than 10 minutes, and improved things greatly. Here are a couple of photos from another thread that illustrate the mod.

HangarRash

I did the same modification to the carb on my Aviastar .46 as ScottMcM did above. Instead of a Dremel I used a small file, and it only took a few minutes also. Much better throttle response from the low to mid range, probably as nice as the other engines I have in its class.

jimmyjames213

My Feedback: (2)

11 grand on a 10x6? thats horrible. my os.40 fp will turn a 10x6 faster than that.
how rich were you set?

ScottMcM

My Feedback: (66)

I was a few clicks off peak. The engines had just been broken in. I imagine they would have loosened up with a little more run time. When I replaced the broken engine with another new Aviastar, it was turning even less rpm's. I never did get it up to the other engine's rpm. Never did get it synced(sp?) like I wanted it. I lost all faith in the engines, sold them with the plane they were on, and gave the remaining engine away, after I modified the carb. (I had 4 of the little jewels) Believe it or not, it is still running fine for its new owner

NM2K

My Feedback: (14)

"Syncing" engines on a model is impractical, unnecessary and unwise UNLESS you "sync" the engines after the needles have been set by varying the throttle control levers. That way you will not inadvertently lean an engine to the point where it overheats and fails.

Normally, experienced folks choose the highest quality, most consistent running engines that they can afford for multiple engined aircraft. That way, problems with less than ideal QC or poor carburetor design are minimized. You did just the opposite. I'm not surprised that you had problems with the Aviastar engines as their carbs have a horrible reputation.

As far as the value of synching goes - well, it sounds neat and if you are onboard a multi-engined aircraft whose engines are out of sync, it can be a pretty uncomfortable experience - like the DC-9 flight I took from Philadelphia to Minneapolis, MN some years ago. I was sitting right in front of the engine(s) air intakes and the heterodyne frequency generated from the sync mismatch was almost unbearable. I finally changed my seat to get away from the sound.

In a model, with no one aboard to annoy with out of sync engines, a minor difference in rpm is nothing to worry about and won't hurt a thing.


Ed Cregger

ScottMcM

My Feedback: (66)

Like I wrote in post #78, I started each engine seperately, tuning each just slightly rich of peak rpm, and then was in the process of syncing them with the mixing of my radio. The reason I had those engines on the twin was that I got the whole package in a trade, plane and engines. I already had the plane (Top Flite Cessna 310), so I really didn't want this one, but it was part of the deal, all or nothing. This 310 had been repaired from an earlier crash, had fixed landing gear.....not a big investment... so I figured, what the heck. My other Top Flite 310 has a pair of Kraft K61's that run perfectly, Robart retracts, onboard glow and a twinsync to add a little insurance in case of an engine out. I agree with you about having dependable engines on a twin, and that is why I finally sold the 310, at a cheap enough price that the new owner could afford to put new engines on it if he wanted to.

NM2K

My Feedback: (14)

Okay, I now understand that you did not use the mixture control needles to match (sync) engine speeds. So what do you suppose changed the mixture enough on the blown engine to cause it to overheat and blow up? Debris in the fuel line? An air leak that permitted the mixture to go lean? Or was it just a plain old connecting rod failure?


Ed Cregger

ScottMcM

My Feedback: (66)

I have no idea. I broke all 4 engines in exactly the same way....one failed....why?....I have no idea.......but, I have had engines run lean before, and none of them failed...

NM2K

My Feedback: (14)

Well, I agree that it would take more than just a single lean run to blow a connecting rod unless the rod was defective to begin with.

We have been reading a lot of good posts about these engines if we exclude the carbs from the evaluation. Unfortunately, a great engine with a bad carb is not a great deal, even at $50. Yes, I've also read where Sig is trying to rectify the carb problem. That is good.

As far as the blown engine goes, have you spoken to Sig about that as yet?


Ed Cregger

ScottMcM

My Feedback: (66)

Didn't say anything to Sig. Just chalked it up to experience, and moved on. Funny thing is the engine that I modded the carb on, and then gave away, is still running perfectly.....go figure