I just installed the enigine on my cap 232/15, it was very difficult, but succeeded, i noticed that the propeller shaft is slightly off (1/8 inch) from the centerline of the fuselage, i was wondering if this error will have much of an effect during flight, any experience with this anyone.

It would have to be a lot farther off than that to notice any effect. The right thrust angle has far, far more effect. I would think the engine would have to be off center at least a few inches to really start noticing anything. Look at how engine pods mounted well off the fuse datum line work and only need a slight up elevator trim to compensate for the offset thrust line.

"Gday Mate,
If it is offset to the right, looking from the tail forward, it is known as right thrust, it is built into the firewall of good aerobatic aircraft to compensate for the torque effect of the prop, You will notice a difference if you don't have it, for a start when you pull up into a loop, the plane will veer to the left, & you will need rudder to stop it from going offline. If it is offset to the left, change it so it is either straight or slightly right, If you have a look in the December edition of Model Airplane News, it shows how to check the amount of side thrust in your plane, page 16 under Tips & Tricks.

As part of this discussion, I am also wondering about L_R thrust. I am flying an newly built Goldberg Extra 300 with an OS 1.08 engine 15x8 prop. When I pull into a vertical upline as the plane goes up vertically, I must continue to add L rudder to keep the vertical straight. The higher the plane goes( and the more it slows down], the more rudder I must add. Is this an indication of the wrong thrust angle or what is causing it?

Are you saying it is angled a 1/8" off or is the engine mounted on the firewall 1/8" off center? If it's angled, it will have some effect, especially if it is in the wrong direction like alan0899 said. You don't want it to be angled left and/or up. If it's just mounted 1/8" off center of the firewall, don't worry about it.

That makes me think it has too much right thrust angle. It it's trimmed to fly straight at speed in level flight where not just the prop wash, but the air it's moving through also determines the trim setting, then when it slows in the vertical with the engine still at full and only the prop wash (at a lot of right angle) is now the only air hitting the tail feathers, the trim would now not be enough and causes you to add left rudder. That's what seems logical to me. Anybody else got ideas?

Looking at it from the tail it is offset from centerline fuselage to the left, 1/8 inch, the firewall (ARF kit), is already canted, slanting left to right to counteract left hand turning tendencies. After thinking about it i think this will not have a notcieable effect on flying characteristics, i could be wrong, i was thinking of adding spacers where the engine is mounted to the mount to pull it back over on the centerline. Also off the subject, I have a .15 O.S. engine, i cannot find bushings to fit around the shaft to fit the prop and spinner, anybody know where to find bushings of this size, 5mm. Local hobby shop has nothing, without this i cannot install the spinner, i can install a master airscrew, it does not need any bushings. thanks in advance.

G'day Mate,
Don't adjust it leave it where it is, the motor is set that way to allow for the cranksahft to be in the centre of the cowl, when ready to fly.