4 needle carb issues

[jtom1112]

Hello everyone

i am having issues with my carb and need advise. its a four needle carb on an Axial 28 rr 2. the engine runs good but i am having issues with the midrange needle backing out and changing my tune while driving. Just when i think I'm good the engine bogs and sputters and almost flames out till i let off the throttle. once back at idle its fine so i screw the needle back flush and try again. from there all is fine till it backs out again. Need some advise. Thanks

 

[2revo1maxx]

Remove needle.
Carefully and gently squeeze the threads with a serrated jaw (the grippy kind) needle nose plier, but not the first 2 or 3 threads.
Apply green slime or silicone lube to the o-ring.
Re-install the needle.

The idea here is to lightly scar the threads so they won't move as easily. By leaving the first 2 or 3 untouched you are guaranteed to get them started back in the hole. I know it seems crude but it will work if done carefully.

 

[jtom1112]

thanks i will definitely give that a try maybe then i can keep my tune and tear s@#t up.

 

[2revo1maxx]

Yeah, but like I said, be careful! If the pliers don't work you can probably find other methods. The basic idea is just to cause a little extra friction between male and female threads.

 

[TaterX]

Blue Loctite is made for this or teflon tape would work if you dont want to chance screwing up your threads. Just be careful how and where. Just a couple wraps around the edge of the threads facing the outside of the carb body.
http://www.loctiteproducts.com/p/t_lkr_blue/overview/Loctite-Threadlocker-Blue-242.htm

 

[2revo1maxx]

That would work, if you know exactly where that needle has to be set. Otherwise you'll have to break the loctite bond to adjust the needle. The residue left behind might still keep it from vibrating loose though.

 

[TaterX]

Ya he said he runs it at flush. I don't think people really adjust the mid range much. Just use a dab and put it back to factory if you have the specs. Good luck

 

[2revo1maxx]

Ya he said he runs it at flush. I don't think people really adjust the mid range much. Just use a dab and put it back to factory if you have the specs. Good luck

Yeah, I know what he said. That doesn't mean it's going to be set just right though.

 

[Phins Fan]

Loctite doesn't leave any room for adjustments as its .......locked tight!!! I have used a similar approach with my hsn when it was backing out and had good success. The key is to take your time and dont rush it. If you rush to bash or race your gonna cut a corner somewhere and screw the screw! Also you need to use a quality set of pliers as a cheaper pair may actually roll the ridges over on the pliers and not your needle causing you to just flatten your screw

 

[TaterX]

Hello everyone

i am having issues with my carb and need advise. its a four needle carb on an Axial 28 rr 2. the engine runs good but i am having issues with the midrange needle backing out and changing my tune while driving. Just when i think I'm good the engine bogs and sputters and almost flames out till i let off the throttle. once back at idle its fine so i screw the needle back flush and try again. from there all is fine till it backs out again. Need some advise. Thanks

That may be true for HSN which may need to be adjusted often depending on conditions and many other factors. He is talking about the mid range needle witch he clearly says he runs it at flush. IMO its never a good idea to mar up threads especially when its being screwed into an aluminium housing. Locktite may lock tight but when you let it cure and break the bolt lose there will still be residue on the bolt that still makes it hard to unscrew there for it wont back out on its own.