dle 35 spark plug installation
 

I have a dl 35 installed on my Taylorcraft. This is my first time using a gas powered engine. The engine is brand new and unbeleivably comes with very little in the way of an owners operating manual. I found an owners manual on line but it does not explain how to install the spark plug into the electrode wire or what the spare spring was for. My problem is I can't figure out how to get the spark plug to fit inside the electrode wire. Also, there is a small spring inside which to me doesn't make sence. There is also an extra, identical similar spring. I took it too the hobby shop where I bought it and although they were just as confused as i was they did say to contact the RC Universe Forum. Also, the minimal instructions said not to use metal cleveces to use plastic only on the throttle and choke, why? Any help with this problem will be greatly appreciated.

At the end of the ignition box wire there is the spark plug boot that is already attached to the wire. Inside this boot is a small spring. Simply push the boot onto the end of the spark plug while slightly twisting the boot side-to-side a little. It will take a bit of pressure but it will push onto the plug and you will feel it when it does.
The outer edge of the ignition boot/cap needs to slide over the metal shell hex of the plug to be considered attached. Again, it does take some effort to "push" the cap onto the plug.

They give you an extra spring with the engine.

The reason they say not to use any metal in your throttle linkages is RF Noise ( Interferance with your Trransmitter signal) I use Sullivan Flex pushrods ( Ny-Rods) for all my throttle connections. A z bend at t5he sevo horn and a ball link at the engine horn. Do not use carbon fiber rod on your throttle linkage either they cause RF noise also. The spring that comes with your engine is basically just a way to get a better connection between the boot and the plug. Just slide the wider end of the spring over the plug and install the boot until it fits on the plug real snug. Wrap the Shielded cord on your ignition ( The one the boot is attached to that has the metal braid around it) with the plastic wire wrap and use whatever is left over to wrap the black wire coming from the hall sensor ( the black magnet sensor on the prop hub) HTH, Rotten

As noted this is to minimize the chances of stray RF generated by vibration of metal to metal connectors, affecting the RC system. Many years ago this was a well know cause of mystery crashs but as radio systems got better i.e. FM, PCM, 2.4 and etcera the fellows tended to forget this. Now when spark ignition engines agine came along this became more important.

Just remember, if the throttle arm on the engine is metal do not use an S bend or metal clevis, not even a metal pinned plastic clevis. If the engine throttle arm is plastic S bend, metal clevis or metal pinned plastic clevis are OK to use. Agine no metal to metal contact at the engines throttle arm.

John

You don't need an extra spring to make a better connection. If it's connected properly it can't be any better. I don't see the point of a spare sorting though. By the time the original one is worn out the whole boot will probably need replacing.

The important thing is to make sure the boot snaps in place on the plug. That's what the spring inside does. Many RF problems have been caused by not pushing the boot on hard enough.