A mate of mine wants to sell me a super tigre 61 engine. It is about 10 years old but looks to be in good condition. It will run on a bench without any problems but in the air it dies all the time.
His guess is that it needs new bearings but I dont think he knows for sure. Can you get new bearings for this motor and if so is it worth doing up this motor? He only wants $50 Aust for the motor which is quite cheap.

Thanks,

Troy.

If it were bearings, it would make all kinds of noise. I don't think that is it. Check the plug, maybe put a new one in it. Check your fuel, take the needle out and blow the carb out and make sure it is clean, then put the needle back in. Check to make sure you are not getting bubbles in the fuel from vibration, ballence the prop good.

Supertigre made good engines. I have run quite a few of them. they are not the strongest on the market, but they run great.

Thanks Flyboy.
I noticed that when I disconnect the glow plug lead at idle the engine stalls so perhaps a new glo plug will do the trick. As for bubbles in the fuel, the plane my mate used this engine in didn't have foam around the tank so thats probably another reason why it didn't run properly.

Thanks again for the advice,

Troy.

If the super tigers are run in correctly they last forever, at $50Aussie it's worth buying for the spares.

Bearings are cheap from the local bearing shop probably only about $10Aussie.

Some ST engines had problams with the carby leaking at the base, take the carby off and refit with a smear of high temp silicon.

Try an OS#3 plug running on 10% nitro fuel and 20%oil.

hows the compresion when it's hot??

Hows the tank height compared to the needle valve?

it the preassure nipple to the tank blocked?

try flying around at as low RPM as possible and see if you get through a full tank OR set it realy rich, if this works it's probably got bad compression, the low rpm or rich setting keep the engine cooler and there fore the compression higher due to less heat expansion.

but as i said $50 is a good price, on ebay thea 61 would probably be over the $100 ausie mark

For Oz$50 I'd grab it. Like FLYBOY says, try another plug. I'm betting your mate had this problem and put it down to air leaking through the front bearing but if the 61 is like my G51 then the front bearing is sealed. ST's are one of my favourite engines.

Well 2 fellow Aussies can't be wrong, even if they are living in the wrong side of the country.....
Yes I agree it is a good deal for only $50. It started first go on the bench and ran well across the entire throttle range. I will check everything out that has been mentioned above.

Can the carby be taken apart easily enough and cleaned? How critical is the direction of the spray bar outlet that these engines have?

Thanks,

Troy.

Oh yes, that reminds me. Make sure you use an air filter to keep the sand out

As for the spray bar, I seem to recall reading they work best when pointing straight down.

Thanks I thought that might be the case but someone once told me they had to face forwards so I wanted to check.

And yes I have an air filter....for the sand.....

Also check your needle settings. If the idle needle's a bit on the lean side, it can interfere with high-speed fuel flow and cause the engine to trend lean as the egnine unloads in the air.

Here's our FAQ on the subject:

http://www.supertigre.com/faq/product-faq.html#q22

Go online to the super tigre web site and download the manual for that engine it will tell you everything that you want to know. I got on of these 61's on a trainer that someone gave me because they could not get it to run. I downloaded the manual and did the things it said and it is one of the best engines that I have. You may need to work on tuning the slow speed needle some. Have fun and good luck.

Rick