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-   -   Reedy 121 Motor help (https://www.rctech.net/forum/offroad-nitro-engine-forum/441398-reedy-121-motor-help.html)

scootinround 10-07-2010 10:56 PM

Reedy 121 Motor help
 
I have a Reedy 121 motor I have run about almost half a gallon in...It idles wonderful and when you bump the throttle it runs perfect but when you come down the straightaway and let off at the end it dies....I have played with it leaning it richin it.....and even had some nirto state series guys play with it and it still does it......I have sealed it...and put 3 glow plugs in it and it still does it....there is no bubbles in the gas line...I did notice a spot on the carb where the flywheel is rubbing alittle ...could this be stopping it..and if so can I shim it somehow.....I am running a FTrc8 clutch.

well any help will help...lol

scootinround 10-08-2010 02:03 AM

Also does anyone know what the stock needle settings are for the Reedy 121VR ...I just want to say I am not to pleased with motor.....Hell maybe I should of went with nova rossi...like everyone tryed to get me to do...but no I tryed to be faithful to Team Associated,,, well look at me now.:flaming::flaming:

Brandon Melton 10-08-2010 06:23 AM

If it idles fine and low end repsonse is OK, you are just out of tune. As for the flywheel rubbing the carb, just loosen the two top screws on top of the carb, then slightly turn the carb until it doesn't rub, the angle will still be OK. To get you in the ball park, start with the LSN just a little out from flush and the high end needle 2 and 1/2 turns out from fully closed. These maybe won't be track perfect for your climate but the engine should at least run around the track and not shut off. When is your next race? I'd be happy to put it in my car and get everything set correctly for you, could have it back to you by next weekend using priority mail. No charge to help you, just get it to me. I could then also tell you where things were out of wack to give you something to keep an eye on for the future.

Also a very quick thing to check for, are you using any brake at the end of the straight when it dies?? If so you could have your linkage wrong where it's holding the carb open just a bit at nuetral and then when pushing the brake it closes the carb. What kind of fuel? I assume it's something fairly fresh from a source that other people are running also.

Snowbum32 10-08-2010 08:18 AM


Originally Posted by Brandon Melton (Post 8043463)
If it idles fine and low end repsonse is OK, you are just out of tune. As for the flywheel rubbing the carb, just loosen the two top screws on top of the carb, then slightly turn the carb until it doesn't rub, the angle will still be OK. To get you in the ball park, start with the LSN just a little out from flush and the high end needle 2 and 1/2 turns out from fully closed. These maybe won't be track perfect for your climate but the engine should at least run around the track and not shut off. When is your next race? I'd be happy to put it in my car and get everything set correctly for you, could have it back to you by next weekend using priority mail. No charge to help you, just get it to me. I could then also tell you where things were out of wack to give you something to keep an eye on for the future.

Also a very quick thing to check for, are you using any brake at the end of the straight when it dies?? If so you could have your linkage wrong where it's holding the carb open just a bit at nuetral and then when pushing the brake it closes the carb. What kind of fuel? I assume it's something fairly fresh from a source that other people are running also.

+1 I bet its the flywhell hitting the carb.

Sylvain 10-08-2010 11:52 AM

Here are the factory settings

High speed: 2 1/4 turns from fully closed
Low speed: 3 1/8 turns from fully closed
Idle screw gap: 1/16"

But follow what Brandon said... This will make your engine runs fine again :)

PowerHouse 10-09-2010 10:23 AM


Originally Posted by scootinround (Post 8042538)
I have a Reedy 121 motor I have run about almost half a gallon in...It idles wonderful and when you bump the throttle it runs perfect but when you come down the straightaway and let off at the end it dies....I have played with it leaning it richin it.....and even had some nirto state series guys play with it and it still does it......I have sealed it...and put 3 glow plugs in it and it still does it....there is no bubbles in the gas line...I did notice a spot on the carb where the flywheel is rubbing alittle ...could this be stopping it..and if so can I shim it somehow.....I am running a FTrc8 clutch.

well any help will help...lol

I can't say for sure without seeing it myself but one of the biggest reason's an engine would do that is if the lsn was too lean. I know you mentioned you richened and leaned the engine but you didn't indicate which needles and in which order. The most common mistake among tuners is they run the hsn too rich and the lsn too lean. That is why you have engines that run great for the first few minutes and slowly develope lean bogs down low and eventually run into what we call ghost flames at the end of a straight. When the engine is on the hsn, with it too rich, it gets plenty of fuel but when you apply the brakes and close off the circuit and become lsn dependant, the lean setting dries out the mixture and the engine starves for fuel and flames out. The flywheel hitting the carb thing may be from times of chassis flex on big landings or if you the car dirt darts into the face of another jump so I can't sat for sure but I don't think the flywheel is hitting the carb at the exact moment you brake at the end of a straight. Not saying it isn't possible as I am not there to see this but I would look into other areas first. If you just can't seem to get it, send it in and I will run it myself and let you know what I find. Also a clutxh spring or bad bearing would also cause this but if it only does it at the end of the straights, unless something really weird is happening with the clutch, I will still lean towards the engine not being tuned correctly but again without seeing your engine and setup, I can't say for sure but it sounds like you have done the basic troubleshooting and all the signs of normal operation seem to be there other than your exact needle positioning.

scootinround 10-10-2010 12:52 AM

Thanks for the help everyone.......I am going to try the factory settins and then fine tune it again...that wont hurt.

ehames005 10-10-2010 01:38 PM

Can this issue also happen with bad fuel? I am having the same issue and I can not get it to tune out.


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