os 50 hyper problems

[allan-]

Can any body help.
I have dead stick issues. I have had no issues with the engine until the last two flying sessions. It starts easy and runs well. The first two times upside down it dead sticked (also my first two autos). So I re piped the tanks and clunk tubes and replaced the glow plug. I had a trouble free flight, including a couple of flips. the next flight I was in level flight and it dead sticked again. I have removed the engine cleaned the carb out before I put it back I checked for play. The only play I can find is about 1mm of end float is this normal? and should check anything else?

[Andy from Sandy]

Do you have a filter fitted and have you also changed that?

Have you checked the rear bearing?

[paul35]

Is it running hot? don't forget to richen up during this crap weather we're having

[allan-]

I checked the filter when i repiped, it was clean. I did not richen up so i will next time. how do i check the rear bearing? I have checked for movement side to side by holding the fan it seams slop free. The end float move about a .75 mm is this ok?

[moyesboy]

its hard to check the rear bearing without taking the motor to bits.
End float is not a measure as the crank can slide in the bearings anyway.
Try removing the glow plug, then feeling the shaft as you turn it. It should be dead smooth with no lumps (you will be able ot feel the ports opening and closing). Any grindyness and you are in trouble.

You can take the liner out and remove thepiston and crank to feel the bearings better.

all the motor maintenance is well explained by Robgt at www.helituning.com

As the bearing starts to go the motor loses tune, and you chase the mixture settings. Then it startsto sound a bit rough on tick over. Then after that the bearing breaks up and its a horror show inside...

Its always worth changing the rear bearing.

[allan-]

cheers everyone. I've took the crank out the rear baering seems ok but I think I will change both bearings. The rest of the engine look good no scoring on the bore. where can I get the bearings from?

[Pitman]

where can I get the bearings from?

http://www.rcheliaddict.co.uk/engine...size-list.html

http://www.fast-lad.co.uk/store/2673...es-p-1993.html but out of stock

[Mslater]

try Simply Bearings Ltd

I would buy part no SKF W619022z - the SKF is my choice because they last many times longer ....

SKF stainless steel deep groove ball bearings are specially designed to resist corrosion. They are ideally suited for application in the food industry and anywhere that requires a bearing which is both hygienic and has a high resilience to water. These single row deep groove ball bearings have the same deep raceway grooves and close conformity between raceways and balls as standard deep groove ball bearings. They can carry axial loads acting in both directions in addition to radial loads, even at high speeds. SKF stainless steel deep groove ball bearings have the same running properties as conventional steel deep groove ball bearings, but have a lower load carrying capacity. The bearings are available in open and sealed designs for shaft diameters from 1 to 50 mm.

[Mslater]

Oh yea, nearly forgot. I had a similar problem, turned out to be the O ring on the align fuel filter.