CRRC Pro GF26I

[3Dguy]

So "right" is wrong?

[Jedijody]

I don't know why but I think most Chinese manufacturers do it the same, even the Rcexl specifications list 35* BTDC as allowable max timing. Don't know if it's because of the gas they have to use or what.

[wilde1j]

Mine was way out of time also. Extending the slots allowed 30° BTDC, which is OK, but not 28° BTDC. When I get some appropriate plastic or aluminum, I will make a new slotted plate and attach the sensor body to it, and slot it for correct adjustment!

[Wingman26]

	Quote: Originally Posted by Jedijody
	The CRRC factory shoots for 35* BTDC for their timing, most all gassers run better at 28* but they won't listen. Your engine was timed "right" to begin with.

Thanks Jody

[3Dguy]

	Quote: Originally Posted by Jedijody
	I don't know why but I think most Chinese manufacturers do it the same, even the Rcexl specifications list 35* BTDC as allowable max timing. Don't know if it's because of the gas they have to use or what.

Oh, I see...

[ipsik]

What would be the downside of 35 degree BTDC timing, more vibration, poor idle?

I moved mine to 28 - 30 degrees using and RCEXL timing wheel and power was down noticebly so I moved it back to halfway between the original factory 35 and 30 so now at about 33 degrees. It runs well but transition from idle to power is poor and slow unless I richen the low end to the point where it 4 stroke at anything less than 1/2 throttle.

Of course it was only + 5 C here and may be hard to get it warmed up enough to transtion smoothly.

[Wingman26]

By lengthening the slots I was able to bring it down to about 30 degrees before TDC, now if the weather will cooperate I might get a chance to try it out, it may be a few days though!

[Crashis Clay]

	Quote: Originally Posted by Wingman26
	Finally got in a position to accurately check the timing on this engine, and this might explain why this engine has been so cantankerous! I had checked the timing before, but there were too many variables to be sure it was correct, I was having to eyeball TDC, looking through the exhaust port trying to find TDC, and I didn't have a firm mount on the pointer either, so my preliminary estimate of 35 degrees before TDC couldn't really be relied on. I have a dial indicator now, and the engine is in the plane and I can firmly mount an indicator, so now its confirmed, the plug is firing at 36 degrees before TDC, with the pickup all the way to one side of its adjustment slot, and about 43 degrees before TDC at the other end of the slot, there is no way this pickup can even be adjusted to the 28 degrees its supposed to be! The mounting bracket isn't long enough to expand the slot to make it anywhere near the correct timing, so something was screwed up at the factory on this one.

What octane are you using? a higher octane might help, (the higher the octane the more resistant the fuel is to combustion) a low octane can lead to pre-detination, low power and over heating

[Wingman26]

I'm using 87 octane, regular unleaded, 100% gas, pre ignition has never been a problem, no ping at all.

[Wingman26]

The fun never seems to end, I tried to start it this afternoon, and it was kicking back with the timing set at about 30 degrees before TDC, so I backed off a bit and it quit kicking back, it only took me a bit over 2 hours to get it started and stay running, it would start and die, start and die, over and over!

Here's a little video of the kicking back, note that it didn't kick back and hit my hand, either time in the video.

YouTube- Engine kicking back

[3Dguy]

	Quote: Originally Posted by Wingman26
	The fun never seems to end, I tried to start it this afternoon, and it was kicking back with the timing set at about 30 degrees before TDC, so I backed off a bit and it quit kicking back, it only took me a bit over 2 hours to get it started and stay running, it would start and die, start and die, over and over! Here's a little video of the kicking back, note that it didn't kick back and hit my hand, either time in the video. YouTube- Engine kicking back

I used to have a huge problem with mine kicking back and loosening the spinner and prop...

[Wingman26]

Thinking about the brief run and quit, engine would start, run a second or two and die. I've been fighting this problem lately, I noticed the red LED for the Opto Kill switch was off, when I touched the ignition wiring it came back on, I first thought it was the switch on the ignition, so I replaced that switch with a known good switch, and was still having problems. Testing the engine again I was having the same problem, and if you got it started it would cut out, I pulled the Opto Kill switch out and it still did it, then I found the battery connector was too loose, so I thought I had the answer. Today I was using a battery that had a good connection and had reinstalled the Opto Kill, and the problem reappeared, so I guess I need to go around the Opto Kill and try it, I may have an 42% Opto Kill that's breaking down with the vibration of the engine starting, so I guess this quest to get this engine running correctly continues.

[3Dguy]

	Quote: Originally Posted by Wingman26
	Thinking about the brief run and quit, engine would start, run a second or two and die. I've been fighting this problem lately, I noticed the red LED for the Opto Kill switch was off, when I touched the ignition wiring it came back on, I first thought it was the switch on the ignition, so I replaced that switch with a known good switch, and was still having problems. Testing the engine again I was having the same problem, and if you got it started it would cut out, I pulled the Opto Kill switch out and it still did it, then I found the battery connector was too loose, so I thought I had the answer. Today I was using a battery that had a good connection and had reinstalled the Opto Kill, and the problem reappeared, so I guess I need to go around the Opto Kill and try it, I may have an 42% Opto Kill that's breaking down with the vibration of the engine starting, so I guess this quest to get this engine running correctly continues.

Check your solder connections as well. I reused an opto kill that was in a crash, and the 26 would run intermittently. When I bypassed it, the engine ran. Turns out the vibrations from the starting/running were jiggling the wires a bit. Now, I make sure all the wires are tied down securely...

[Crashis Clay]

	Quote: Originally Posted by Wingman26
	The fun never seems to end, I tried to start it this afternoon, and it was kicking back with the timing set at about 30 degrees before TDC

that kicking back that you are experiencing is pre ignition, try some premium grade fuel with no ethanol and bypass your kill switch and make sure you have the NGK plug in the engine, these are the first things I would try, maybe you have already I dont knw....... just trying to help

[Wingman26]

I'll give that a try.