gunny11

My Feedback: (6)

I have an RCS 44 twin and when I restart it after say 10 to 15 minutes. It KICKS BACK like a mad bull. Gloves or no gloves OUCH[:@]!

Need some light shed on this topic before I shed some fingers.

1. Could my ignition be going bad? Not retarding for starting?

2. Is my low end needle too lean or rich? It worked fine at this setting for the first tank and a half.

3. I cleaned and put all new gaskets on and in the carb. This did'nt help.

4. I found a head leak in one of the cylinders. Fixed that, but that did'nt help either.

I did a search on the RCS engines and found that some had bad sensors or ignition moduals.

Thanks in advance,

Gunny

Antique

My Feedback: (4)

Bad battery or bad module..Carb settings have no relation to timing and will not cause kick back if the ignition is timed correctly and the battery is good...If too lean it just won't fire at all....This is for mine or C&H ignition, don't know about the foreign stuff...If an engine has mechanical advance and the pilot tries to start it with the throttle too far open it will kick back...

gunny11

My Feedback: (6)

I see, I'll throw the battery back on charge tonight and see if this makes a big difference. I havent re-charged the battery in a couple of days. Although it was reading 5.35 volts under no load. I know my falcon unit on my ZDZ will work as low as 5v under no load. Maybe twins are different even though it states 4.5v to 6.0v.

O.k. so needle settings havent' any affect on the kickback. But what about a head leak or carb/gasket leak. Anyone?

Thanks RCIGN1 for the insight.

Gunny

BobH

My Feedback: (2)

Gunny, leaks cause one thing only, a lean running engine. Since air is a lower viscosity than gas its easier to draw hence the lean condition. Two cycle engines (at least the conversions) are intended to be started with a pull rope. This typically pulls the fly wheel fast enough to prevent kickback plus the timing is often fixed for optimum hi speed running. If your timing is not properly set (plane engines) kick back can occur. It simply sparks too soon before top dead center and sends the crank (via piston) shaft back down in the wrong direction. If your engine was hot enough (too lean?) it might pre ignite causing kick back. In effect its desieling and igniting with out the spark plug. Excess carbon on the piston can cause that too .. Just a few thoughts. BobH.

gunny11

My Feedback: (6)

It's like the modual unit is getting "stuck" at full advanced. Like not reseting to full retard at start up.

Gunny

pacrat

dont know if this will help, but is the plug gap to wide? (my mvvs was doing the same thing this was the fault)

TLH101

My Feedback: (90)

A flooded engine will kick back real hard even with timing retratred. My A&M 42 smacked me real good once just from being flooded. A friend has been bit by his 3.7 twin from it being flooded also.
I now choke all my engines by flipping with ignition on. That way when it has enough fuel, it will fire and try to run. Then open choke and 2-3 flips make it purr. I also always use a glove now. I have not been bit since I changed my starting method, but.................
A bad sesor can cause a C&H ignition to kick back also.

gunny11

My Feedback: (6)

Thanks for the reply guys.

I had checked the gap in both spark plugs before putting them in for the first time. But good point. It did'nt do it in the first tank and a half, unless they opened up in the first 2 hours of running the engine. BTW the plug gap was set correctly at the factory at .015"

I tried also the variouse starting techniques with the choke and without even using the choke, Still kicks back hard.

So I think were narrowing it down. Modual or sensor. Thanks TLH101 I did'nt realize that a bad sensor could also do this. I will try a new replacement Modual first and if it still does it then I'll suspect the sensor is at fault. And who knows, It very well may be because the previous owner/operator must have used pliers to remove or futs with the sensor. The plier marks on the sensor is now questionable.

Thanks

Gunny

flyn2high

My Feedback: (2)

Hi Gunney

If you have kickback with an electronic ignition engine there is something wrong with the ignition unit or timing setup.

I bet it would not be too much trouble to put an automotive timing light on it. You could magic marker a line on the prop hub that lines up with the crankcase at TDC. When running you should be able to watch it advance as you increase the RPM.

The recommended advance setting on the Brison at idle and starting is 0 to 2 degrees before TDC. At high rpm it is about 28 degrees.

If you need one I can bring mine to the field.

By the way my G38 kicks like no tomorrow if it is warm and I choke it to much. I am thinking of converting it to CH Ignition or coming up with a better method of choking it.

Lou

excaliber

TIMING,

gunny11

My Feedback: (6)

Hi Lou. I totally forgot to post my findings, (a year and three days later) Look at my last post date 4/16/04.

The problem was long solved. It was a bad batch of spark plugs and the ignition modual. Lou, this is whats in my Patty Wagstaff. It flies it great and absolutelly no problems with it for 10 months now. In fact I just flew it again 4 times this past Sunday and it fired right up on the first flip. Have a total of 34 flights on her.

Thanks,

Gunny

flyn2high

My Feedback: (2)

Hi Gunny:

Nice work. I looked at the date and thought it was current but I was a year off.

See you tonight ant the meeting

Lou