Lesson 3... Jetting a Savage... (blah, blah, blah,... it's about dang time!...)...
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Now,.. for some specifics on the Savage and it's carb...
The Savage uses a round slide Mikuni BS40 carburetor...
Mikuni is a very popular carb, and jets are widely available at most bike shops and sites...
The BS40 used a large round Mikuni main jet,... and that's what you ask for at the shop...
The pilot is trickier,... best to take it in and have it matched, or find a link to the correct one on this site...
Mikuni jets are numbered in increments of 2 1/2... (ie,... 145, 147.5, 150, 152.5, 155, etc...) These are refered to as steps...
One step, is 145 to 147.5,... two steps would be 145 to 150... and so on...
Each step up, richens the fuel ratio...
The stock bike, in it's current US model configuration, has a #145 main jet, and a #52.5 pilot,
with a 0.1" thick nylon spacer under the slide needle...
As it is... the stock bike is jetted slightly lean (smallish jets) for sea level, where it is emission tested for importation...
The stock jetting is pretty good for elevations in the 2500ft to 5000ft range...
On average, one step smaller in jet size every 3000ft elevation... That's a very variable rule... Temps and humidity make a difference too...
One step larger from stock for sea level, maybe two if it's a very humid location...
Here's a chart of the jetting that comes from the factory,... 95' to present 2011 is the same...
http://i600.photobucket.com/albums/tt82/serowbot/CarbSpecs.jpg As a basic starting point for mods...
The most common mod to better breathing on the Savage, is to swap to a free flowing air filter (foam or k/n fabric), and install a Harley Shorty muffler...
With this mod, you are allowing the engine to breath in and out a little better, ... and it will in turn, want a corresponding increase in fuel delivery to match the extra air...
If your bike was jetted fairly well in stock configuration for your location,... adding these two mods will want about a two step increase in the overall jetting...
From stock,.. say, from a #145 to a #150 main,... from a #52.5 to a #55 pilot with a little more opening on the idle mix screw (1/2 to 1 turn more)... and a reduced spacer thickness on the needle slide from 0.1" to .066" or 0.50"... (you can sand the stock one down, or buy #4 nylon or brass washers to vary the thickness)...
Note#...#4 Teflon washer from Ace hardware is exactly 2/3 thickness of the stock spacer and will fit perfect. It comes in white or black. It is just what you want. One and only one. It will measure .066",... stock is .1"... that''s the standard starting point for a Harley muffler w/ free flow air filter....
An even more open pipe, or a cam with more lift, or other more extreme mods,... will require more jetting.
The basic tuning range will go from...
#125 to #160 with the main...
#47.5 to #60 with the pilot...
... and from 0.1" to no spacer at all on the needle jet...
Info on choosing a Harley muffler is available here...
Harley muffler guide... I hope this info somehow clears things up, more so, than adding to the confusion..
It's not a cut and dry process... and many experts will disagree with each other...
... and I'm not an expert... but I have some experience...
So,.. now you know what I know...
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