i think i have an air leak, how do i know for sure?

[jalikaria24]

i had a big red .28 sitting for a while and i recently took it apart and cleaned it and put it together. it believe i did a goof job on taking it apart. however the first day i ran it, it had a high idle and then i took it home and adjusted the gap and now i believe the idle is good however i noticed that the hsn and lsn are basically flush but the engine runs HOT, like its already so rich and its getting past 300f when stressed. i also noticed on wot i dont see blue/white smoke. When i step on it from start to mid power band i can see some smoke and when i blip the throttle at standstill however when it passes 1st gear it basically has no smoke. i dont know if its because of the speed and the smoke dispersing maybe but i believe something is up for sure. i bought some copper permatax and I'm going to seal the backplate and carb area and then also put some green slime on the carb o rings. i also suspect my hpi aluminum pipe has a leak where it fits into the silicone coupling but i put a new one but i think even if there was a leak near the coupling it wouldnt give the symptoms I'm getting, i could be wrong tho. i noticed this issue even when the tank was full full so i dont think its half tank lean.

anything else i should do or check?

 

[olds97_lss]

A leak at the header where it connects to the engine or at the pipe wouldn't cause it to be too erratic, just make a bit of a mess more than normal.

A leak at the carb neck or combustion chamber would be more obvious in regards to bad tune I'd think. If you have a can of compressed air, get it running, then spray compressed area around the carb seat and see if the engine pitch changes at all. Also try around the base of the head. Can also use WD40, but that would make a mess.

 

[Chubaka]

Old school way.. Make sure its all screwed together but out of the car. Cover carb with a fuel bottle cap, block off exhaust port, and have a plug in. Blow air in the carb through the fuel line when its under water. The air will bubble out.

Keep in mind no water can get in the engine. Also it will rust screws.