I read your other recent post about your bike and modifications.  You’ve got a lot going on.  I black poof could be nothing (afterburn).  If it’s running great as you said and not smoking when your riding, I’d just watch it.  If the mods were done recently, it could be just about anything.  Watch your oil level.  I don’t like any color smoke and assume oil bypass because I usually assume the worst.  How’s your gas mileage?

If you are running the stock carb......the pilot jets with holes in the side have no affect on the fuel mixture.  Those pilot jets are made for carbs that have an air supply to the side of the pilot jets, and the stock carb has no air supply to the area along the sides of the pilot jet.  The fuel mixture will not vary if you use the single hole jets - or the ones with holes on the sides...they will provide exactly the same restriction as long as the single end hole is the same. The air that mixes with the fuel from the Pilot jet is provided up in the carb body above the float bowl.  Next time you have your carb off remove the pilot jet and look closely down into the recessed hole the pilot jet screws into....and you will not see any passage to permit air to flow to the pilot jet.  


NOTE:  The stock carbs on my little Ninja 250 had holes in the sides of the pilot jet, and a small amount of air was provided to create an emulsion in the body of the pilot jet.  When you closed the throttle during and created a high vacuum situation - the Ninja had an air supply valve that would close and stop the air flow to the sides of the jet to resolve the Lean condition that occurs when you close the throttle at higher rpm....on the Savage the TEV does this - and the system on the little Ninja worked much better.  So...on some carbs those little metering holes in the side of the pilot jet do work - but not on the Savage.

It is my belief that a pilot jet has very little affect on how a bike runs - the affect is mostly on how it idles and how the engine responds when you roll the throttle slowly on.....if you crack the throttle open quickly the needle and main jet are now controlling the mixture.by way of the vacuum operated slide.  If you get the smoothest idle with the idle fuel mixture screw 1.5 -2.5 turns out - the pilot jet is sized correctly.  If you can turn the screw all the way in without experiencing a drop in idle smoothness, the jet is too big.  If you have to turn the screw out more than 3 turns and don't experience a "rich" idle...the jet is too small.  All idle fuel adjustments should be made withe the engine fully hot and the idle speed dropped temporarily to around 800 rpm......adjusting the mixture at a higher rpm is not effective as the slide will be opening and you will not get a noticeable change when moving the mixture screw.  Once you have experience with this adjustment you should be able to make it in less than a minute or two.....then turn the idle speed back up.

Man this old bike. I love it but I'm almost ready to give up and just stick with my honda.

No matter what size pilot jet and pilot air screw settings I use, I get this really poor idle and low throttle sputtering. As you can see by the video I'll link below, it's when I'm only just touching the throttle, which is bad because that's where I am when I am filtering through traffic or driving through a parking lot and it sputters poorly. The video is with a 52m5 pilot, one turn out.

I've tried jets from 47.5 up to 55. . It's definitely leading to a rich idle, whatever the issue is.

I'm wondering if it could be a low rpm spark issue?  I think it could be as it used to just miss every minute ot 2 and have a tiny sputter at idle, but it's progressing now.

It's all good wiring and original electrical.

Went to start it today and it won't even start now. I went back to the spark plug which was replaced a week ago and it was black again.
Replaced the plug, which still didn't want to start, and even gave a couple of pops back through the carb. Spark is blue and pretty bright
Maybe the damaged choke is the culprit.  The plastic thread is broken and has been like that since I bought it.
I'm thinking about replacing the carb entirely. Might even try a cheap eBay knockoff just for fun

It is currently using the 160 main jet, back to the 147.5 pilot, a needle with washers to match the plastic spacer size as its broken.

Really just want a bike that will run for more than a month at a time at this point.

The EEN needle is almost impossible to find. Wonder if the EEM would be ok.

Moarpower wrote on 06/09/23 at 01:22:51:


That is an indication that the mixture is lean under light throttle just as the slide begins to lift.  Remove 1 washer and try 2.

Dave wrote on 06/09/23 at 04:17:01:


Removed one washer and the issue is still present. Also seems to be running a little rich with only 2 washers.

Maybe the 155 main jet is too big. It my needle and needle jet setup or wrong.