F4.6 driving me crazy!!

[MySavageWillBeatYours]

I have a F4.6 on my savage that develops an air leak from the carb slide once its warmed up good. It sounds like Chewbacca getting electrocuted when its leaking. Only does it at idle. Sometimes I can blip the throttle and it stops leaking. The tune is spot on while its cold and warming up but after 5 or so minutes of running it starts leaking. I sprayed wd-40 on the slide while it was lean and that made it calm down for a second or two. The carb was replaced last year for this problem. So the original carb and the new one does the same thing. Has anyone else had this problem? I'm thinking about swapping a different brand of carb on and see what happens. Any insight will be highly appreciated.

 

[NightFlier X4.6]

How long did it take before it started with new carb.

 

[MySavageWillBeatYours]

Maybe a few months.

 

[NightFlier X4.6]

Have you disassembled the carb and looked at the seal's?

 

[MySavageWillBeatYours]

I just took it apart and sure enough, there is wd-40 all over the slide. I cleaned everything and sealed the boot with some RTV. Hopefully that will fix it. The boot looked good with no holes.

 

[Jam Racing 1]

https://www.hpisavageforum.com/threads/nitro-engine-sealing.15150/

Possibly your needs a good cleaning and sealing, use associated green slime on all o rings and seal the well, you will surprised how well it will run once sealed up correctly......

 

[MySavageWillBeatYours]

Update, I sealed the carb slide boot with RTV and retuned. Now it runs better at idle but I think I might be overgeared. When I run it hard the temps get close to 300 and thats when it seems to chewbacca at idle. If I let it cool down to around 260 it idles good. Before it would idle lean all the time after warmed up. I have a hole cut in the windshield and the body is open at the back around the engine. I'm running HPIs Bronco body. Its geared 18/47, high speed XL 3 speed, bulletproof diffs, and stock SS wheels with Dirtbonz tires. I did manage a 43mph pass in a parking lot at work. What do you guys think? Overgeared or tune issue?

 

[espdgonzo]

does it start to stall out at full throttle or start to choke out? sounds like you might be to lean. i would rich it out some and see what that does for you.

 

[MySavageWillBeatYours]

espdgonzo you got it. It was a tad lean on the HSN. Retuned and now it idles good and stays around 250-260. Thanks.