Hello everyone,

A friend of mine has this engine in his Aeroworks Yak and is still having problems with it. We have tried everything we can think of, including a new tank, fuel lines, stopper etc., etc., etc., but the same problem still exists. The engine is connected to evgerything just like the instructions say. The low speed and high speed screws on the carb is set to the recommended settings, but the engine WILL NOT run with the pressure line for the tank connected to the carburator like is done with other gas engines. If you take the line off, the engine appears to run fine until you hold the plane up vertically. At that point the engine will not lean out no matter how long you hold it up at a constant throttle setting, but when you reduce the throttle and then go to increase it again, the engine will slow down but it will quit when you increase the throttle.

My friend will appreciate any assistance with this issue because he really wants to fly his Yak without worrying about the engine. I have also learned a valuable lesson from this. I will never buy an Evolution engine for a plane of mine..[:'(]

Fly safe and have fun!!
David

I haven't met a gasoline engine we use for our hobby yet that uses tank pressure, the vent line on the tank is vented to the atmosphere, perhaps you are talking about the pulse line that the carb would use for case vacuum pressure to pump fuel? Get the plumbing straightened out first, and take your time setting the carb for your location, temp, altitude...etc. no factory can preset a carb and have it work fine everywere. the engine might start at those settings, but that might be about all you could expect. If you are talking about the air pressure inlet, it is also vented to the atmoshphere. The fitting is there in case airflow around the engine causes a change in atmospheric pressure, and you have a need to route this vent, say into the fuse of the plane, where the pressure is more constant. Definitely don't route this vent to your tank

Nothing could be easier than setting up a gasser...
ONE line from the clunk in the tank to the fitting in the body of the carb...
ONE line from the tank vent to atmosphere...
NO line to the fitting on the steel cover on the carb...
Open both carb needles 2 turns...
Start engine..
Set high needle for max rpm, open about 1/4 turn..
Set idle speed to about 1800, slowly close low speed needle..the rpm wil increase...
Reset to 1800, lean some more, try transition...
Repeat until the transition doesn't work...
Open the low needle until the transition comes back...
Re check the high needle...
Go fly.....
These engines are not plug and play, it takes a little fiddling around to get the correct settings...

Careful Ralph........

One line from the rear of the motor crankcase to the carb is the pulse line on the 58.

there are some good pictures in the MVVS forum which is the same motor.

Sorry, I was ASSuming no one would take some lines off a carb that are already there, to attach a fuel line...
Looked at the picture on Horizon's web site, it looked like the fuel connection is on the bottom...

There are two covers on the carb one is pressed steel and one is cast:
Connect the nipple on the cast cover to the engine back plate.
The nipple on the pressed steel cover is too atmosphere.
The nipple on the side of the carb is connected too the tank, no other connection too the tank from the engine.
The tank is vented to atmosphere, take the vent line up over the top of the tank so that it will not allow petrol to siphon out when you get fuel in it during aerobatics.
I use a three pipe system in my tanks with the third pipe to the bottom of the tank for filling and emtying this is Plugged after filling.

Mike

Thanks for the helpful information, and will forget the smart mouth.
Unfortunately when I purchased the engine the pluse line was not connected and the picture in the instructions was not clear. Originally we tried running the engine with the pulse line connect to both nipples. The engine would only run with the pulse line disconnected. After getting the engine to run as it should,we have reconnected the pulse line to the proper nipple, the engine richened up and we have been able to adjust it to run correctly in all attitudes.
Thanks again,
Burnley

Glad to have been some help.

Mike