spasmatic

My Feedback: (4)

My RCGF 20cc engine will not start since I had a hard landing, nothing broke, just splayed the landing gear a bit. I checked the fuel tank and the clunk had kinked itself. That was fixed. Next checked to see if spark to plug and it has one. If I prime it through the exhaust it will spit, almost backfire and quit. The plug is wet, so I think the carb is pumping fuel. Next I wanted to check the timing and I have a problem for me anyway. Looking at the engine from the front, the magnet is left of TDC and appears the correct degrees. It seems to me the magnet should be to the right of TDC if it is in the correct position. Am I wrong and looking at it the wrong way?

spaceworm

I think there is a setscrew that positions the prop driver/magnet ring properly on the crankshaft. Perhaps the landing sheared that setscrew and allowed the magnet ring to rotate out of position?

Regards, Richard

w8ye

My Feedback: (16)

Here's how to set the timing

[youtube]http://www.youtube.com/watch?v=GBXFpxWg7vY&feature=player_embedded[/youtube]

Below in the PDF files are instructions from a couple different companies with a degree wheel you can print out and glue to a piece of plywood

av8tor1977

My Feedback: (6)

Here's another one for ya!

AV8TOR

captinjohn

New Idea for the DLE30. Below is a sensor ring I made for a SuperTiger .90. I am thinking of making about the same thing for my DLE30 engine. The timing could be set real easy by loosening the set screw. Some plastic pick-up holders with slots will not allow enough movement.

I am also wondering if placing the magnet out further from center of prop shaft will be a good thing or a bad thing. I guess it may change dwell time a little? What do you experts think? Thanks Capt,n

Tired Old Man

My Feedback: (1)

So the major difference in setting the timing is loosening one screw instead of two? If the mounting holes for the stock sensor bracket are reasonably located setting the timing as it currently stands is quite simple.

NM2K

My Feedback: (14)

And you have found the problem. At TDC, looking at the front of the model, the magnet should trip the Hall Effect Transistor to the right of TDC. How much depends up the lag in the electronics. But you can't have advanced timing if the magnet does not trip the Hall Effect Transistor BEFORE the magnet reaches Top Dead Center. This means the two must encounter each other to the right of TDC.


Ed Cregger

Piston

My Feedback: (1)

Here is the easiest way to set the timing... You don't have to worry about about degree wheels and printing them out , cutting wood and confusing yourself...etc...
To check the timing will take you 1 minute or less. It is good for any engine with the rcexl or like ignition system
[link=http://www.rcaer.com/pages/Articles_and_Formulas.cfm]Timing your engine the easy way Article 7[/link]


The RCGF 20cc is probably using their home version of the electronic ignition. Check it out..If so.. I have found that this version has been prone to vibration and hard knocks. Another think to look at are the connectors. They are very very delicate and bend and break easily.
The engine many be okay.. the ignition may even be okay.... and that is the case... go with the hall sensor check it out and the connections.

Cheers
Henry

captinjohn

<hr />It is a two fold experiment to see if having the magnet further out from center of prop shaft would be a better thing. Dau...I know about the slots. I guess you have not read where you sometimes you need to re-slot the pick holder. Please answer all the question...or just pass it bye..........................

Tired Old Man

My Feedback: (1)

I don't know if moving the magnet outward would have any impact at all. It would only impact the relative position of the magnet to the center of the crank, making for slightly finer timing points. Our ignitions don't recognize minor variations in timing points. They are all out advanced after about 2,500 RPM. People think we have a "curve". Not so. We have a simple ramp up from about 5* to between 27* and 30*. Our ignitions are not high tech, high accuracy devices by any definition.

If the sensor is aligned properly with the magnet it should work correctly if mounted a foot away from the engine. Everyone knows about having to re-slot the bracket at times but does making a new timing ring simplify that issue for the average user? Nothing new about timing rings, they've been there since the days of mechanical advance ignitions.

coralcape

My Feedback: (4)

In answer to post #1, If you are standing in front of the model, looking toward the rear of the model and the engine is at TDC, the sensor magnet will be to the left of the sensor. I find it on average to be about 3/8-1/2" past. Good luck, red

Antique

My Feedback: (4)

Why make a simple process into a big deal ?
Turn the ignition on...Rotate the crank CCW, when you hear the spark make a pencil mark across the hub and crankcase...
Multiply the hub diameter by .244
Put the piston on TDC...The two marks should be that distance apart....Takes 5 minutes if you're slow...

Sheesh...
If yoiu go throug alll the trouble of making a degree wheel and check this out, you will see how much time you wasted....[>:]

NM2K

My Feedback: (14)

Actually, now that I think of it, it doesn't matter where the pick up is, as long as the magnet is in the correct position relative to the pickup. Doh!


Ed Cregger

Tired Old Man

My Feedback: (1)

[sm=thumbs_up.gif]

apalsson

My Feedback: (1)

I kinda struggle with seeing how the problem can be the magnet in the wrong location or a timing problem bad enough to stop the engine running. The problem started after a hard landing? Meaning the engine has already run properly?[sm=confused.gif]
A shocker of a landing if it shifts the magnet in the hub (or the pickup for that matter) []

Tired Old Man

My Feedback: (1)

Hard landing.... Hmmm. Hard enough to splay the gear? Engine not running when it hit? Hard enough to hit the plug with an inverted spark plug installation?

Something to ponder that all except one missed with earlier magnet position posts. The ignition, when timed correctly, triggers at about 28* before TDC. So when the engine is at TDC the magnet would be to the left of the sensor slightly when looking at the engine from the front. The ignition triggers off the trailing edge of the magnet.

spasmatic

My Feedback: (4)

I would like to thank everyone who replied to this thread. You were very helpful. The biggest problem I had was getting my 70 year old brain wrapped around something simple. When I looked at the motor from the front, I somehow was using the sensor as the TDC timing mark and thus made the position of the magnet seem in the wrong position. After reading through the replies and especially by TOM it cleared the cobwebs.