CRRC PRO GF26I
#851
RE: CRRC PRO GF26I
Here is a pic of the failure. High RPM's should not cause a failure like this. It appears the metal is just too thin and breaks just past the weld. I have had 3 of these mufflesr do the same thing. The engine is running smoothly and the only thing I can think of is the motor box is weak and allows too much movement of the engine. As for prop selection, I'm flying a Yak and I want a larger diameter prop to get outside the cowling. The manufactures spec states max power is at 9,000 rpms. I used a 17x8 and got 7400 rpms then switched to the 17x6 and got 8200 rpms and noticed about 10+% increase in thrust but no real increase in top speed. The muffler failure is caused by vibration and (IMHO) is related to manufacturing materials or proceedures.
#852
Senior Member
RE: CRRC PRO GF26I
Hi All.
I have a 69" Extra 260 with a CRRC-Pro up front running a SY16X8 prop with a Pitts muffler.
Had nearly 18 months and lots count of the number of times its flown. I fly nearly everyweek, not always this Aircraft though.
Its ran like a dream. The only thing I had to do was swap out the defect prop adaptor as it cracked.
I was even using the SY 16X8 3 blade for awhile. Nice prop, smooths out the engine and looks great. The reason I went back to the 2 Blade is spin up time. The 2 blade was instant. 3 Blade takes a sec to wind up.
Cheers
Grossy
See pics
I have a 69" Extra 260 with a CRRC-Pro up front running a SY16X8 prop with a Pitts muffler.
Had nearly 18 months and lots count of the number of times its flown. I fly nearly everyweek, not always this Aircraft though.
Its ran like a dream. The only thing I had to do was swap out the defect prop adaptor as it cracked.
I was even using the SY 16X8 3 blade for awhile. Nice prop, smooths out the engine and looks great. The reason I went back to the 2 Blade is spin up time. The 2 blade was instant. 3 Blade takes a sec to wind up.
Cheers
Grossy
See pics
#853
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RE: CRRC PRO GF26I
HELP!
This engine (26EI) runs great when it runs FORWARD! It loves to run backward! In fact when it pops, it throws the prop backwards and starts right up. Several HARD flips to get to go the right way. When it runs forward, I get great response, good idle, good transition to full. No problem there.
When it pops backward though, to breaks loose the prop bolt from the shaft and spins it off, prop, spinner and all, in one piece!
Any corrections for the backwards pop? Timing? Anything?
And the prop shaft unscrewing? 10 lbs./sq.ft. torque right?
Prop hub. (gold anodized) is fine. no cracks.
Any help would be appreciated.
This engine (26EI) runs great when it runs FORWARD! It loves to run backward! In fact when it pops, it throws the prop backwards and starts right up. Several HARD flips to get to go the right way. When it runs forward, I get great response, good idle, good transition to full. No problem there.
When it pops backward though, to breaks loose the prop bolt from the shaft and spins it off, prop, spinner and all, in one piece!
Any corrections for the backwards pop? Timing? Anything?
And the prop shaft unscrewing? 10 lbs./sq.ft. torque right?
Prop hub. (gold anodized) is fine. no cracks.
Any help would be appreciated.
#854
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RE: CRRC PRO GF26I
ORIGINAL: scratchbildr
HELP!
This engine (26EI) runs great when it runs FORWARD! It loves to run backward! In fact when it pops, it throws the prop backwards and starts right up. Several HARD flips to get to go the right way. When it runs forward, I get great response, good idle, good transition to full. No problem there.
When it pops backward though, to breaks loose the prop bolt from the shaft and spins it off, prop, spinner and all, in one piece!
Any corrections for the backwards pop? Timing? Anything?
And the prop shaft unscrewing? 10 lbs./sq.ft. torque right?
Prop hub. (gold anodized) is fine. no cracks.
Any help would be appreciated.
HELP!
This engine (26EI) runs great when it runs FORWARD! It loves to run backward! In fact when it pops, it throws the prop backwards and starts right up. Several HARD flips to get to go the right way. When it runs forward, I get great response, good idle, good transition to full. No problem there.
When it pops backward though, to breaks loose the prop bolt from the shaft and spins it off, prop, spinner and all, in one piece!
Any corrections for the backwards pop? Timing? Anything?
And the prop shaft unscrewing? 10 lbs./sq.ft. torque right?
Prop hub. (gold anodized) is fine. no cracks.
Any help would be appreciated.
I know how annoying it is to re-tighten the prop and spinner only to have it spin off on the next flip.[:@] Good luck.
#856
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RE: CRRC PRO GF26I
Thanks for the reply.
It's not that the prop and spinner "kicks" off, but the whole shaft as well. Prop stays tight against the stop.
I have double nutted the prop.
It's not that the prop and spinner "kicks" off, but the whole shaft as well. Prop stays tight against the stop.
I have double nutted the prop.
#857
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RE: CRRC PRO GF26I
The shaft comes out too? Tighten that sucker up, but don't overtighten. I gave it more than 10 ft/lbs. A better idea would be to find the cause of the backfiring, but, I still have no idea...
#858
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RE: CRRC PRO GF26I
OK. It dosen't backfire.
Flip the prop, prop turns 1 revolution, as the magnet comes around to fire the next turn, it's like it pre-ignites causing the prop to kick in reverse, then start. Backwards.
I know the timing is retarded, but how much should it be?
And, what is the stock setting?
Flip the prop, prop turns 1 revolution, as the magnet comes around to fire the next turn, it's like it pre-ignites causing the prop to kick in reverse, then start. Backwards.
I know the timing is retarded, but how much should it be?
And, what is the stock setting?
#860
Senior Member
My Feedback: (1)
RE: CRRC PRO GF26I
Does the large part of the propshaft that threads onto the crankshaft go all the way down flush with the surface of the gold prop hub or does it stick up slightly above the serrated surface of the hub?
Timing should be set at 28-30 degrees BTDC, sometimes they get set to far advanced or you may just have a bad module.
Timing should be set at 28-30 degrees BTDC, sometimes they get set to far advanced or you may just have a bad module.
#862
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RE: CRRC PRO GF26I
Hey Jody. I've heard alot about your expertise on these. Thanks for chiming in.
The propshaft just barely sticks out. The spinner backplate does touch the hub. I'm not sure how much though. It's a 3 1/2 in. dave brown alum. It's in a 25% yak, so the visual is slightly impaired.
I don't see how it could be the module. When it fires forward, it runs great. Running on 4.8v.
The propshaft just barely sticks out. The spinner backplate does touch the hub. I'm not sure how much though. It's a 3 1/2 in. dave brown alum. It's in a 25% yak, so the visual is slightly impaired.
I don't see how it could be the module. When it fires forward, it runs great. Running on 4.8v.
#863
Senior Member
My Feedback: (1)
RE: CRRC PRO GF26I
If the spinner back plate is just touching it may not be enough to get a good bite on the hub serations. Here is something to try to keep the propshaft from getting spit back at you when it pops backwards.
Unscrew the propshaft, take the lock washer out, clean the threads and put red Locktite (262) on the threads inside the propshaft and reinstall without the lockwasher, let it sit overnight. This will let the spinner back plate make full contact with the prop hub so the serations can do their job.
As far as starting backwards, this is the first 26cc engine I've heard of doing it. It was more common with the 50cc and was always associated with the timing being advanced to far. Check the timing with a degree wheel and see what it is exactly. They are usually at about 30 degrees from the factory but I have seen them as far as 36. Set it at 28 degrees and give it a try.
Besides that you can try to flip it over either a little harder or a little softer, sounds weird but sometimes it works. Get the engine right itself though first, if you don't, there will always be something else going on that will be a pain to deal with.
If you can't figure it out don't give up on it, take a break and fly something else, send it in and I'll take care of it.
Unscrew the propshaft, take the lock washer out, clean the threads and put red Locktite (262) on the threads inside the propshaft and reinstall without the lockwasher, let it sit overnight. This will let the spinner back plate make full contact with the prop hub so the serations can do their job.
As far as starting backwards, this is the first 26cc engine I've heard of doing it. It was more common with the 50cc and was always associated with the timing being advanced to far. Check the timing with a degree wheel and see what it is exactly. They are usually at about 30 degrees from the factory but I have seen them as far as 36. Set it at 28 degrees and give it a try.
Besides that you can try to flip it over either a little harder or a little softer, sounds weird but sometimes it works. Get the engine right itself though first, if you don't, there will always be something else going on that will be a pain to deal with.
If you can't figure it out don't give up on it, take a break and fly something else, send it in and I'll take care of it.
#864
Senior Member
My Feedback: (1)
RE: CRRC PRO GF26I
Jody, my 26cc has been doing the exact same thing. I believe it all began after replacing the module. The sensor is retarded all the way but it still starts backwards, 3 to 5 times, before it finally starts right. Once it warms up, it won't start backwards again, it only seems to happen when it is cold. I don't really have a problem with the prop as I don't use a spinner and the prop shaft is fairly tight. But I am always concerned that something might break loose one of these days.
#865
Senior Member
My Feedback: (1)
RE: CRRC PRO GF26I
Hi Joe,
Not sure exactly what is going on except this is the second engine doing the same thing, has never been an issue with the 26 and as you know, it was not a problem for you until you replaced your module. Look at the pictures and notice the differences in the sensor and battery leads. Also look at the back of the module and note which model number is marked off and please report back. It would help if you could acurately check your timing with a degree wheel. If you don't know how or don't have a degree wheel go here, http://www.ch-ignitions.com click on "Instructions" and then, "Installing and Operating...", scroll down about 3/4ths of the page you will find good directions on how to do it. There is also a link at the end for a degree wheel you can print out. Before you print it make sure you have the scaling turned off in the printer properties dialog box that pops up.
Not sure exactly what is going on except this is the second engine doing the same thing, has never been an issue with the 26 and as you know, it was not a problem for you until you replaced your module. Look at the pictures and notice the differences in the sensor and battery leads. Also look at the back of the module and note which model number is marked off and please report back. It would help if you could acurately check your timing with a degree wheel. If you don't know how or don't have a degree wheel go here, http://www.ch-ignitions.com click on "Instructions" and then, "Installing and Operating...", scroll down about 3/4ths of the page you will find good directions on how to do it. There is also a link at the end for a degree wheel you can print out. Before you print it make sure you have the scaling turned off in the printer properties dialog box that pops up.
#868
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RE: CRRC PRO GF26I
Nah, I think I read somewhere that the electronics are under some kind of impenetrable black blob. Best not to risk electrocution! haha The module is zip-tied and duct taped securely in the Showtime 90, so I'll tinker tomorrow. [sm=redface.gif]
#870
Senior Member
My Feedback: (1)
RE: CRRC PRO GF26I
ORIGINAL: jedijody
Hi Joe,
Not sure exactly what is going on except this is the second engine doing the same thing, has never been an issue with the 26 and as you know, it was not a problem for you until you replaced your module. Look at the pictures and notice the differences in the sensor and battery leads. Also look at the back of the module and note which model number is marked off and please report back. It would help if you could acurately check your timing with a degree wheel. If you don't know how or don't have a degree wheel go here, http://www.ch-ignitions.com click on "Instructions" and then, "Installing and Operating...", scroll down about 3/4ths of the page you will find good directions on how to do it. There is also a link at the end for a degree wheel you can print out. Before you print it make sure you have the scaling turned off in the printer properties dialog box that pops up.
Hi Joe,
Not sure exactly what is going on except this is the second engine doing the same thing, has never been an issue with the 26 and as you know, it was not a problem for you until you replaced your module. Look at the pictures and notice the differences in the sensor and battery leads. Also look at the back of the module and note which model number is marked off and please report back. It would help if you could acurately check your timing with a degree wheel. If you don't know how or don't have a degree wheel go here, http://www.ch-ignitions.com click on "Instructions" and then, "Installing and Operating...", scroll down about 3/4ths of the page you will find good directions on how to do it. There is also a link at the end for a degree wheel you can print out. Before you print it make sure you have the scaling turned off in the printer properties dialog box that pops up.
#871
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RE: CRRC PRO GF26I
Sorry for the typo, it should read 13lb, I edited the post to reflect the change. Actually I got 13.5lb with the SY16X8.
Thanks for pointing the typo.
Ed
Thanks for pointing the typo.
Ed