Posted by sabatig on Monday, March 15, 2010 @ 06:09 AM:
Hi All
Arriving into the hanger for the first time in a long time, and atempting to start the rf3 nothing!!
Off with the plugs to check the sparks and it is only sparking on 2 of the 4 sparks.
Quick question, has anyone been able to get the Mag off the RF3 without removing the engine?
Thanks
Gino
Posted by SteveBeaver on Monday, March 15, 2010 @ 08:15 AM:
You can certainly get it off an RF4 by removing two engine mount bolts and tilting the engine and mount. No idea if the same is true of a '3.
Posted by Bob Grimstead on Monday, March 15, 2010 @ 08:46 AM:
Like this:
http://www.cfiamerica.com/images/Mira-engine.JPG
We found it difficult, but we did it.
Yours, Bob
Posted by sabatig on Monday, March 15, 2010 @ 09:06 AM:
Thanks for the prompt Reply!
Will give it a go - anyone else had spark issues when the a/c has been sat in the hanger for a few months over winter?
Gino
Posted by SteveBeaver on Monday, March 15, 2010 @ 09:17 AM:
Oh yes! - I would guess your contact breaker point gap has become too small due to slight wear in the nylon cam follower. Clean and adjust the contact breakers and you will have an easy to start engine once again.
Steve
Posted by Donald on Tuesday, March 23, 2010 @ 05:28 AM:
The RF3 does not have the 'swing down' engine mounts as in the RF4, so you will have to lift the engine off the firewall to get at the magneto.
It is possible to reach the magneto from the cockpit by removing the bowl from the back side of the firewall, it's held on by 4 nuts on captive screws, but access is difficult and you'd be much better to bite the bullet and take the engine right off. It's not too hard a job. Disconnect the throttle, choke and decompressor cables. Disconnect the fuel line, the oil temp and pressure senders then all that's left are the 4 engine mounts. You'll need some sort of lifting tackle but the engine weighs a lot less than a person so it doesn't require anything exotic. I made up a 4 to 1 hoist from pulley blocks and rope from my local marina. One of the pulley blocks has a built in jamming cleat so I can lock-off the rope whenever I want.
[Edit by Donald on Tuesday, March 23, 2010 @ 09:20 AM]
Posted by Bob Grimstead on Tuesday, March 23, 2010 @ 10:10 PM:
Yes, That's pretty much how I did it.
This is what they mean by 'maintenance in the field'...
The engine's weight is not being carried by the hangar's structure, but by three shear legs made out of surplus lengths of the same type of tubing. There is no pulley at the top, only a bolt with a sleeve, so I had to heave hard to overcome the friction.
The block of wood is back-up.
Good luck.
It might be wise to change the HT leads while you are doing this.
You do not want to have to do it all again later in the year.
Yours, Bob
Posted by Donald on Wednesday, March 24, 2010 @ 10:03 AM:
No pulley? Damn, that's hard.
Posted by sabatig on Friday, March 26, 2010 @ 05:57 AM:
Hi All
Turns out it was nothing to do with lack of sparks...My muppet engineer/co-flyer claimed it was (something I always doubted). Before we started the job off with the hanger lights, low and behold all 4 plugs sparked up the darkened hanger...
Was a fuel issue, all sorted now runs beautifully. Thanks for all the help.
Posted by Donald on Monday, May 3, 2010 @ 06:35 AM:
In sabatig's opening post he asked if it is possible to take the magneto off the RF3 without removing the engine. I now know this is possible but I recommend a little intelligent preparation. Turn the engine to the timing point for the No1 cylinder, 30° before TDC. That's what the magneto needs to be set to so if you leave it like that it will be a simple matter to regain the timing on reassembly.
You need access to the rear of the firewall so first thing out is the wheel case then tie the gear doors up so that you can work through the gear opening.
Remove the fibreglass bowl containing the magneto, it's held on by 4 nuts on captive screws, M7 I think, maybe M8, spaced at the upper and lower 'corners' of the bowl.
Next you have to remove the P lead and the distributor plate. For safety I'd suggest removing the distributor plate first by taking out the 4 screws. The plate should then just pull off though you might feel some resistance because the rubber disc underneath is a little 'stuck' to the plastic of the distributor.
Unscrew the P lead from the top of the mag.
All that remains is to release the two M13 nuts, one on either side of the magneto, then withdraw the magneto from the coupling.
To reassemble, remove the plug from the side of the magneto distributor, the underside when the magneto is on the engine, bring the marked tooth on the gear into the middle of the port or set against the alignment index if there is one, and slide the magneto back into its coupling. You can adjust the advance a little by rotating the magneto on it's two studs. Ideally with the crankshaft set the magneto marked tooth will align in the port.
You can see a few photographs of my magneto coming off here. http://picasaweb.google.com/donmcnicholl/RF3GATBP# They are not a dis-assembly sequence but just to show what's underneath.
[Edit by Donald on Monday, May 3, 2010 @ 08:29 AM]
Posted by Jorgen on Monday, May 3, 2010 @ 03:04 PM:
Thanks Guys for taking your time to write down your experiences and ad pics to your posts. It´s invaluable information for all of us and is very timesaving since we all have to make the same operations sooner or later.
May the 4's be with you/ Jörgen
Posted by Donald on Tuesday, May 4, 2010 @ 08:30 AM:
You're welcome. Sharing helps us all.
I should add a footnote to my magneto post. I was concerned that I might lose the order of the HT leads as they fit into the distributor cover plate so marked everything possible, but that magneto plate can only be fitted in one orientation. The screw hole pattern is not symmetrical so if you don't disturb the HT leads in the distributor cover you won't lose the distribution order.
Donald
