Motor rev high out of nowhere

Petrolheadz100

Well-Known Member
Messages
243
Running my buggy yesterday and I noticed after the end of the run it started to accelerate by itself and was moving forward very slowly revving High I turned down or reaching the low-speed needle to calm it down but why would it do this? I had to richen up the low end about a quarter of a turn for it to sound like it was before it's running okay but it does seem to be too rich on the bottom and because it slightly bogs when taking off how can I get this problem fixed. Is it an air leak or maybe something getting loose on the carburetor bolts?
 

G-Man

Junior Member
Messages
871
Location
Pittsburgh,PA
Running my buggy yesterday and I noticed after the end of the run it started to accelerate by itself and was moving forward very slowly revving High I turned down or reaching the low-speed needle to calm it down but why would it do this? I had to richen up the low end about a quarter of a turn for it to sound like it was before it's running okay but it does seem to be too rich on the bottom and because it slightly bogs when taking off how can I get this problem fixed. Is it an air leak or maybe something getting loose on the carburetor bolts?
You can try spraying carb cleaner around all the gaskets on the carb and head. Although it is highly possible the carb insulator that bolts in between the head and carb could be warped or cracked, it is plastic. Good luck
 

pfrederi1

Well-Known Member
Messages
104
I had same problem of just HI Revs out of nowhere after my MT was running fine the other day. Let me ask this, when you make the adjustments are you getting a desired response?

With my problem I was adjusting everything (idle screw, LSN) and no response. Did a once over looking at everything couldnt find anything out of place. Took it home and partially broke it down and like G-Man said found that one of the bolts on the insulator block vibrated loose which was letting in air. Tightned her back up runs fine.
 

Haroldbee

Well-Known Member
Messages
49
Running my buggy yesterday and I noticed after the end of the run it started to accelerate by itself and was moving forward very slowly revving High I turned down or reaching the low-speed needle to calm it down but why would it do this? I had to richen up the low end about a quarter of a turn for it to sound like it was before it's running okay but it does seem to be too rich on the bottom and because it slightly bogs when taking off how can I get this problem fixed. Is it an air leak or maybe something getting loose on the carburetor bolts?
Did you inspect your clutch to see if one of the clutch-springs are broken or loose? I've had my Redcat Rampage XR suddenly start revving high and took off on me. The issue, it turned out, was the clutch.
 

Petrolheadz100

Well-Known Member
Messages
243
Yes i had hat clutch spring snap before it wants to roll even at idle but no, i took everything apart and replaced insulator gasket tightened her up and runs perfect , all the screws seemed fine except just one carb bolt was about 1/8 backed out almost nothing but that may have been the issue...thanls guys
 

Ice_2k

Senior Member
Messages
1,391
could be the tank venting issue. If it happens again, try loosening the tank cap. If revs go down, there's your problem.
 

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