n9 assembly questions

[Hassan]

hi guys. im almost done with the assembly of the n9.but i couldn't put in the fuel tank stopper,it is too tight. I also tried to adjust the fan shroud so that it doesnt touch the fan but its still touching.what to do?

[Awamori]

These are two things that I had to work with too and it took some time. For the stopper I lightly coated it with after run oil just because I was afraid of cutting it due to its tight fit.

The fan this last time was so hard to get perfect it was driving me nuts. I push the fan with one hand in different places then tighten the screws when I hear no rubbing. Last time I heard just the ever so slightest rub at one part of the full turn and I left it just because I was so tired of messing with it. After 1 flight I checked it and heard nothing and saw no plastic powder so all is good. Every other time I have set-up the N-9's fan I have been able to get it silk on the bench it just takes time. I have spent 30minutes alone doing just that. Seemed like days. Good luck

[Hassan]

thanks for the tips.

[cdrking]

Another trick with the fuel stopper is spray is with rubbing alcohol.

Yes the fan can be a pain in the a!@#$.

Jeff

[tec548]

I had problems with my tank grommet as well. It kept leaking even with a brand new grommet. The tank had no extra flashing on the edges either.... all trimmed smooth. I put in a 600N fuel tank grommet and the problem was solved. Fits perfect and no leaks!

Joel

[Airboss]

best for stopper is food grade silicon spray. fan shroud alignment is hard but it will line up, tighten screws in small steps while checking rub.welcome to N9s .

[Chuckie]

Try these steps to get the motor mounted in the right spot. Its a bit long at first but you'll see all these steps are needed and it gets quicker every time you need to adjust the motor.

1) Install the engine, engine mount sides, engine mount center block, engine shims, fan shroud, and pinion bearing block with all screws and bolts. Do not tighten screws and do not install the hex adapter. Lightly tighten only the screws mentioned at each step.

2) Lock pinion block. With the engine in position so the pinion and main gear are tight, press down and tighten the screws in the pinion bearing block.

3) Set the height of the engine. You want the engine as high as possible but you also want 0.25 to 0.5mm up and down play in the clutch bell. Snug up 4 engine bolts to engine mount sides and 8 engine mount sides to engine mount center block.

4) Fan Shroud. Tighten the fan shroud screws and check for the fan rubbing by rotating the clutch shaft. Move the shroud forward and back and if necessary set height by moving as much as the screw holes will allow. You might have to reset the engine height to prevent fan from rubbing. Install engine exhaust header/muffler and check shroud clearance. Have some gap between the shroud and muffler.

5) Pinion to main gear play/back lash. Loosen the screws holding the engine mounts to the side frame, without changing the height adjustment set in step 3, and set main gear back lash. While holding the clutch bell move the main gear and set so there is a very little back lash throughout the entire gear. Rotate the gear every 30 degrees and check for some back lash. If the gear is out of round set a tight condition at the high point and allow the gear to wear in the first few flights.

6) Clutch shaft in frame alignment. Remove the pinion bearing block and check distance on both sides from inside side frame to clutch shaft. The measurement should be about 0.4inch or 10mm or the same on each side. Loosen 4 screws for ONE engine mount at side frame and move engine to set same distance. Tighten 4 engine mount and recheck gap.

7) Install pinion bearing block and Hex adapter. Hex adapter M4x6mm set screw (100-466) should have a taper on the end so it fits into the funnel shape hole. If height of engine has changed set position of pinion bearing block so the clutch bell has some up and down play. See step 3.

8) Add locktite to the appropriate screws shown in the manual and fully tighten all screws.

Charles

[MarshallB]

I finally got tired of messing with the stopper in the tank. I went to the LHS and bought a DuBro 2 oz. airplane fuel tank. Cat No. 402. I used the Black cap and the black rubber grommet that came with it. I kept shaping the hole and grommet till it fit. By using the screw compression fitting, it doesn't even think about leaking. Technically speaking, this should be done to all heli tanks that run under pressure. At least when you adjust the carb settings, you know the tank hasn't started losing pressure..

[RyanW]

Check to see if your fan shroud is slightly bowed in toward the inner part of the fan. If so, run it under hot water and put something in the opening to keep the surfaces parallel. Let it cool and then go through Chuck's procedures.

As for the stopper, just use your muscles :)