Here are a couple more tips on the Hartman mod. The end of the muffler is pretty thin sheet metal, if I was doing it again I would cut the end of the muffler out using a hole saw not a torch. Stick a piece of wood in the exhaust pipe at the end of the muffler to keep the hole saw center drill from wandering while cutting. It will be a lot easier to weld it all back together by just filling the hole saw cut instead of dealing with the damage a torch can do. The end of the muffler is made out of two layers of sheet metal welded together at the spotwelds, you need to cut through both layers with the hole saw or torch, I would recomend cutting through at the spotwelds, that should give you enough metal to weld it back together again. It's a fun project and is easier with the muffler off the bike, I did it with the muffler mounted on the bike but I never said that I do it the easy way

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If you check out the tech section you will see some good pictures of the carb in different forms of disassembly. There is a good shot of the white spacer on the needle. The hardest part of working on the carb is getting the stock philips head screws out of it, I had to use a miniture pair of channel locks and could only turn the screw about 1/16 of a turn at a time. If you do decide to work on the carb replace the stock hardware with allen heads, it just makes life a lot easier.
The stock main jet in all the newer Savages is a 145, That's what I had in my '02 and that's what is in yours. The deal with the white spacer is that it makes the bike run a little lean in the midrange. Some riders pull the spacer out completely with no problems, others say without it the bike runs rich, that's why I replaced it with the washers that are 1/2 the thickness of the original white spacer. If you are planning to work on your bike you should get a Clymer's manual, it's worth the money. Good Luck and Enjoy you Savage