thenova70ss

iTrader: (53)

Hey guys i have a Mugen MR Ninja .21 the motor has around 2gal and has ran GREAT but this last weekend at the races it started to give me troubles.I had a great tune on it and was running in a race and half way about 3 Min's in to the race it started to Lean Bog on me so i came off the track and after the race i retuned it and ran a half a tank in it and it ran great so up comes the next race and it started out Great but about 5 min in to the race it starts to Lean Bog so i pulled it off the track all i can think is it has an Air Leak but what is th BEST way to check for an air leak.

P.S It is Lean Bog on the Bottom down the strate it will Bog and then pick up and run great.Could it be a Air leak on the LSN.

jamiekerr14

[url]http://www.youtube.com/watch?v=epEGetU7NFU[url]

Hitman Racing 1

could have air leak, but air leaks I have had caused the engine to rev real hard. To check for air leaks first pressure test your tank, plug the line going to pipe and suck air out throught the line going to motor, suck air out cap hole with tounge suck more air out etc etc, let it sit for a second with tounge capping the line then pop the top on fuel tank and see if it is holding pressure. For the motor take air filter off and maniflod, plug the carb and manifold hole with your fingers, attach fuel line to your hsn valve. fill a cup up with soapy water, i use a turkey baster to pump air into the fuel line while doing that I use a paint bruch to rub the suds over the motor checking all seals, carb etc etc. Hope this helps.

thenova70ss

iTrader: (53)

Link dose not work THANKS

wallot

http://www.youtube.com/watch?v=epEGetU7NFU

Hitman Racing 1

Its probably a video of what I just explained to you.

Gary NJ

iTrader: (8)

Another way to check:

GMK Supply Leak-Seek-R

Miniracer23

I didn't watch the videos, so you might have seen this already, but if you start up you engine and hold slight throttle. Take a can of carb cleaner or brake clean and spray the back plate seams and carb seals. If the engine quits instantly or bogs majorly, you have an air leak in that spot. Also, spray behind the flywhell to check if the front bearing is leaking.