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Bogs out in 2nd

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S

shiflett104

RC Newbie
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hi, i just got my 2.5r up and running again. it seems to run fine untill i open it up, it gains speed untill it seems like it should hit 2nd gear then boggs out till i let off the gas. I've been messing with the carb for a whole tank and can't get it straigtened out. I've only ran like 10 tanks thru. just enough to break it in and play alittle. I'm just getting frustrated with the tuning. any help is greatly appreciate
 
I am having the same problem, it was only happejing when the temps were up at 270+ so i richened it up to keep the temps down. It started to run ok at that richer setting but it was way too rich. So i attributed the rising temps to a worn out engine clutch. So I'm putting everything back together now in hopes the clutch was slipping too much heating up the clutch bell and motor. Let ya know how it goes. Ill lean it back out to how it should be and see if the temps stay low enough and not make it bog in second. Also a high temp leading to a bogging second gear in a well tuned motor may be related to the pinch. I'm thinking the high temps make the sleeve expand and its loosing compression. As soon as my motor cools its fine.

What are your temps like when its bogging?
 
=

if the engine starts and runs fine when cold but not when hot, the compression is usually bad enough that you need a new piston and sleeve.
 
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Thats kinda what i figured. i bought my revo used and battered real cheap so a new motor has been on the list. I'm going to try out the new clutch and see if it helps and if not it will be my break in clutch on a new 3.3.
 
If its SCREAMING in first ( engine realy winding out fast ) you probably have top adjust your shift position.

I had that happen, it would litteraly max out engine speed and "hop" I adjusted the shift point lower, now it flies.

How to change it is in the manual. SMALL adjustments.

Also buddy had similar problem, his would REALY SCREAM, but then DIE not bog, needed a new plug. Might want to try that before replacing engine. Yes a bad plug will run BADLY, I always thought if it was running the plug was OK , this is NOT the case.
Try a new plug.
 
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Set ur high needle to factory and then adjust ur low needle itll fix it i had the same problem it fixed it
 
Thanks to everyone for the info, when i ran it last i used the last of my gas i had left over from the winter, wasn't sure if that was it. i had it running really good at one ponit untill i messed with the needles. i was hoping it wasn't the engine or clutch considering its damn near brand new. this weekend i will try what you all said with the needles and the shift point and check the temps I'm running and let you know how i made out. THANKS :)
 
You can tell if your piston and sleeve is shot or not simply by turning the motor over by the pullstart or spinning the flywheel with your fingers with the motor installed.

Besides that, it simply sounds like your engine is out of tune. The HighSpeed Needle needed to be riched up a tad. Hopefully you've got it figured out and are already to run again.



-Sean
 

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