CRRC 26cc HELP!

FlyingWithRyan

Elite member
I know this engine isnt the greatest but I at least would like to get it running okay. I can get it to idle decently but whenever I add throttle all it does is bog! Ive tweaked the high and low needles thinking the mixture is wrong with no changes. I took apart the carb and found nothing in the screen. Im new to gas so I have no clue what else could be wrong. Contemplating just dropping a DLE 30 in and calling it a day.
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FlyingWithRyan

Elite member
Ive also taken apart the tank lines and put new tygon line in. Theres plenty of fuel getting to the carb but Im not sure if the engine is seeing it or not
 

Bricks

Master member
If the engine has been sitting for along time did you clean out all the little holes when you took it apart. Those holes are so small that it does not take much to block them up get some carb cleaner and give it a good cleaning. Many times what happens when these engines sit for along time the gaskets dry out and the fuel pump does not work properly. One other thing to check is the vacuum hole that runs the fuel pump that they line up with the crankcase and spacer this has been an issue with some engines causing it to run bad. . There is nothing wrong with the CRRC engines.
 

L Edge

Master member
Don't know what engine size you have, but if you think the engine is good, is you prop the correct size and pitch? If you have too big a diameter prop or too much pitch, you will never get the engine to run right.

I have found that you need to adjust the high end first and then work on the low end. Important point is that if you adjust the high end, you always need to re-adjust the low end. What controls everything is how the mid range runs. So it ends up a give and take game. For 3D hovering, it has to be right on in the mid range.

Are you using leaded or unleaded fuel? What grade?
 
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FlyingWithRyan

Elite member
Don't know what engine size you have, but if you think the engine is good, is you prop the correct size and pitch? If you have too big a diameter prop or too much pitch, you will never get the engine to run right.

I have found that you need to adjust the high end first and then work on the low end. Important point is that if you adjust the high end, you always need to re-adjust the low end. What controls everything is how the mid range runs. So it ends up a give and take game. For 3D hovering, it has to be right on in the mid range.

Are you using leaded or unleaded fuel? What grade?
Prop is the correct size for the engine. As the title states its a 26cc to be specific a CRRC GF26i. Unleaded 97 octane with 40:1 mix. The issue is the engine just wont build RPMs above idle. You get that bog sound from the carb any time you add ANY amount of throttle. Even like 5% more throttle.
 

FlyingWithRyan

Elite member
If the engine has been sitting for along time did you clean out all the little holes when you took it apart. Those holes are so small that it does not take much to block them up get some carb cleaner and give it a good cleaning. Many times what happens when these engines sit for along time the gaskets dry out and the fuel pump does not work properly. One other thing to check is the vacuum hole that runs the fuel pump that they line up with the crankcase and spacer this has been an issue with some engines causing it to run bad. . There is nothing wrong with the CRRC engines.
Do you by chance know what carb is on the engine I think someone said a WT-793a or something similar but Id like to get a gasket rebuild set. They dont look dry or cracked but I reckon itd be a good thing to cross off.
 

PsyBorg

Wake up! Time to fly!
I was going to suggest to replace the "O" ring that usually sits on the venturi where the Carb mounts. If that is sucking air it would drastically change your idle tune which in turn would not let any decent response above idle as you are already feeding too much fuel to compensate for the added air.

Another thing to do is start from scratch and properly set the opening for idle using the proper feeler gauge then do a normal base setting for your mixture screws and see what you get.
 

Chuppster

Well-known member
I would set the carb at 1.5 turns for each screw. If it bogs, work the High Speed needle out in 1/4 turn increments. If the problem gets worse, work it in using 1/4 turn increments.

If that doesn't help you, it's probably timing. Does it have an RXCel ignition?
 

Bricks

Master member
I was going to suggest to replace the "O" ring that usually sits on the venturi where the Carb mounts. If that is sucking air it would drastically change your idle tune which in turn would not let any decent response above idle as you are already feeding too much fuel to compensate for the added air.

Another thing to do is start from scratch and properly set the opening for idle using the proper feeler gauge then do a normal base setting for your mixture screws and see what you get.


On a gasser there is no O ring it is a gasket. On a gasser you do not want to even use the throttle idle stop screw, other wise the failsafe will not kill the engine since it is ignition

Did you take a look at the reed valves when you had the carb off for chips or fitting properly , they should fit flat against the reed block. .By the picture I am assuming this is a rear carb if so that is the newer CRRC 26 engine..
 
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Bricks

Master member
Check the carburetor isolator block if this engine has one I have had a few that have cracked.
 

PsyBorg

Wake up! Time to fly!
On a gasser there is no O ring it is a gasket. On a gasser you do not want to even use the throttle idle stop screw, other wise the failsafe will not kill the engine since it is ignition

Did you take a look at the reed valves when you had the carb off for chips or fitting properly , they should fit flat against the reed block. .By the picture I am assuming this is a rear carb if so that is the newer CRRC 26 engine..


Ahh I did not notice that.. I assumed nitro. Guess Ill drop outta this then as I am not up on RC gas motors.
 

Bricks

Master member
Ahh I did not notice that.. I assumed nitro. Guess Ill drop outta this then as I am not up on RC gas motors.


NAAA al ot of the same principals apply but even a nitro you do not want to us the idle screw on the engine same reason.
 

PsyBorg

Wake up! Time to fly!
NAAA al ot of the same principals apply but even a nitro you do not want to us the idle screw on the engine same reason.

Just going back to my schooling for car / diesel engine building... start at the very basics for troubleshooting. Final set up is a different story. Ya gotta start at a stable point no matter what ya do. Even from my mini bike days as a kid shorting anything with a spark plug
to ground was always the shut down method... fuel starving was the method for nitro motors I was taught. Like I said with air planes too many people have different ideas how to do things so I stick to basics that I KNOW work.

Anyway not here to debate things.. Say my peace and move on. If someone uses my advice and it helps great.. If they don't use it great.. either way doesn't effect my flying, driving, or floating. My stuff works as intended for the most part.
 

FlyingWithRyan

Elite member
On a gasser there is no O ring it is a gasket. On a gasser you do not want to even use the throttle idle stop screw, other wise the failsafe will not kill the engine since it is ignition

Did you take a look at the reed valves when you had the carb off for chips or fitting properly , they should fit flat against the reed block. .By the picture I am assuming this is a rear carb if so that is the newer CRRC 26 engine..
Theres no reeds in a side intake engine. The GF26i was the older CRRC
 

FlyingWithRyan

Elite member
On a gasser there is no O ring it is a gasket. On a gasser you do not want to even use the throttle idle stop screw, other wise the failsafe will not kill the engine since it is ignition

Did you take a look at the reed valves when you had the carb off for chips or fitting properly , they should fit flat against the reed block. .By the picture I am assuming this is a rear carb if so that is the newer CRRC 26 engine..
I would set the carb at 1.5 turns for each screw. If it bogs, work the High Speed needle out in 1/4 turn increments. If the problem gets worse, work it in using 1/4 turn increments.

If that doesn't help you, it's probably timing. Does it have an RXCel ignition?
The low needle was at 1.5 turns out and the same for the high. It might be timing but it has the CRRC stock ignition. It really does idle fine though.
 

OliverW

Legendary member
The low needle was at 1.5 turns out and the same for the high. It might be timing but it has the CRRC stock ignition. It really does idle fine though.
For a new gasket I would use permatex ultra copper. It makes a fantastic gasket, and if you put them on the muffler bolts they won't come off!
 

FlyingWithRyan

Elite member
If you bring the high speed out to 1.75 does it make a difference?
What about 1.25?
No matter what needle setting I have it makes minimal difference. Theres one tiny spot on the low needle the idle sounds like it picks up a little but no difference when the throttle opens