Originally Posted by
Riketsu
I was tuning a friend's engine, and it was a bit weird. If it wasnt around what you are saying: HSN = 1 1/2 and LSN = 1/2, it wouldnt run fine. I tried resetting the needles back to stock and work my way from there like I always do, but no, it didn't work.
My suggestion is take the engine apart and inspect everything, dismantle the carburetor and look for damaged o-rings. When you are mounting everything back together, be sure to seal correctly neck of the carburetor since this is primarily where it leaks.
You can also slap in another carburetor if you can get your hands on one to start eliminating suspects.
But as a friendly advice, I currently am running 3 different novarossi engines (2 SCT and 1 353), and all of them are no where near 1 1/2 and 1/2. So it may be something wrong or it may be just that your engine runs there. Either way check it out to be safe.
Ive tried diffrent pipes, and longer pressure line from the pipe to tank and if this 353 dosen't have the hsn at 1 1/2 and the lsn at about 1/2 turns out its not happy. It dumps too much fuel in the engine if its any richer. I want to try changing the hsn and the piece that it goes into but if thats dosent change any thing what then? Replace the carb and it might do the same also. Could the problem be too much back preassure and it is over preasssurizing the tank and forcing too much fuel?