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.25 Carb?

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Newb86

Newb86

RCTalk Racer
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Location
Wausau, WI
RC Driving Style
  1. Bashing
I want to rebuild my 25 carb because it seems very sticky and dosent hold a tune very well this would be the first carb I have ever rebuilt can some one tell me all the parts needed?

Or is it cheeper just do buy a whole new carb if so which one?
 
I think it would be cheaper and easier to buy a new one, you can find them on ebay. Then you have an old one to take apart and look at and find out how it works.
 
Clean it with some denatured alcohol, maybe soak it good. Make sure the idle screw is in the groove properly, it will cause the slide not to move freely. Also make sure your engine is sealed good, especially around the carb neck. In my experience if it won't stay tuned it's usually an air leak somewhere. But it is cheaper to buy one rather than repair one if you get it off ebay and buy the carb body and use your old parts. I did find a complete carb for around $25. As for the parts, buy an o ring set, the rubber dust cover (think they come together), and maybe the low speed needle. It's the one thing I've seen most messed up. Also the .25 and 4.6 carb are interchangable.
 
Did you take the pinch bolt assembly completely out? Be careful though,the 25 carb has an insulator sleeve and if you break it loose you'll have to buy a new carb body or complete carb. It will not tighten up with the loose sleeve.
 
DO NOT MESS AROUND LIKE I DID AND PULL CARB LOOSE BUT LEAVE SLEEVE IN!!!!!!!! It's a pain to get out. If you can't get it out it's cool. Unscrew your LSN then unscrew your idle screw and pull your slide out.Unscrew the HSN clean it all with some alcohol and maybe a old toothbrush. Inspect your LSN for any damage at the tip. Check your O rings for wear and tear. Get you some Permatex form a gasket (1B) from your local auto parts store and put a good bead around the base of the carb, both ends of the bolt that pinches the carb (especially the end without the hex head on it/ of course make sure to tighten it up first), and behind your pullstart or rotostart. Let it dry good and put it all back together. In my opion you really shouldn't havee to buy anything but a dust boot or a LSN unless of course you do like i did and try to force the carb out by prying it up which will result in the plastic part being stuck in the motor.:hehe:
 
The carb was loose when i bought the engine tried tightening the pinch bolt and it didnt help I'm sure its leaking. I either wanted to rebuild it or replace it but at least i wanna get it off so i can run some rtv around the body so i can seal it. I went through this engine last night and found multiple leaks, the back plate- which i rtv'd, the head it was tight but was leaking from the shims I believe so i took the 1 out i think was causing it to leak and left the other 2 and tightened it back up another is the bearing behind the flywheel but i can't find a part # to replace it and the biggest air leak i couldnt fix is the carb.. The reason i went through the whole engine was because i ran it yesterday afternoon and it was running oddly great for a change had good smoke makeing good power then i brought it back by so i could check the fuel and it just did sound right idling so i checked the temp. and it was 320!!! killed the engine right then cooled it down to about 130 then ran the last of the tank out which only took about 3 min and it was back up to 280. So when i got home i tore it down and found all the leaks.
 
If the carb rotates but won't come out,the insulator sleeve is probably already broken loose. Trying to use rtv and seal it won't hold for long,you will never be able to get it to stay tight and the rtv will loosen up with just a little run time. At this point, the only thing I can say is to pry and pull and get it out however you can. Then be ready to buy at least a carb body.
 
1421 is the front bearing and 1422 is the rear. I forgot i super glued my carb 1st then rtved over it. That's a new adverb by the way! (rtved) I found a carb main body for bout $20 on ebay and fixed right shortly afterwards.
 

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