When you are going down the highway and "slowly" turn the throttle to accelerate, is there a point where it seems to run out of power before you have reached Wide Open Throttle ?  Maybe 3/4 or 7/8 throttle ?
Or does it continue to accelerate strongly all the way to wide open ?
If it is strong all the way then you have the correct size jet.
If it runs out of power before reaching wide open then you need a larger main jet.

And you need to swap the white spacer for 3 washers, or if you have the old style needle with the 3 grooves then perhaps drop down 1 groove, especially if the clip is on the top groove.

Island road, Idle jet from idle to 1/4 throttle,needle jet from 1/4 to 1/2 throttle,jet needle from 1/2 to 3/4 throttle,main jet 3/4  to wot(wide open throttle).  Normal steady road speeds 35-65 mph,2300 to 4100 rpm,is between 1/4 and3/4 throttle ,If you don't do the spacer mod you are generally running lean,even more so as your at sea level, which can cause surging ,bluing of your exhaust, because the motor runs hotter .THe stock spacer is plastic and can be reduced by running it across sandpaper laid on a flat surface.I would start by reducing it by 1/4 then by 1/2 if surging continued .THen test your main jet.

Maybe this will help you to understand where the throttle position affects where the fuel is coming from.  You don't need to worry about the shape of the slide cutaway or needle taper - those are already worked out and don't need to be fussed with.

What you need to work on is the "clip position"....which is the height of the white spacer.  Only the very early Savage models had a multiple grooves and the clip on the slide that could be adjusted (or folks who order the expensive Dynajet kits).....the rest of us only have 1 groove and we have to cut down the height of the white spacer or use washers to adjust the height of the needle.

Several of us old farts have been through this before, and you really need to understand that we have a good understanding of this issue......you need to reduce the size of your spacer if you want to cure this lean condition at mid-throttle.  That will allow the needle taper to be a bit higher in the slide - which will allow a little more fuel flow at the throttle setting where you are having a "lean surge" issue.

Ride Report:

So I jumped in and did the spacer mod (thanks for the nudge). I was able to get to the carb through the top without removing it, after taking off the seat and the tank.

I got some washers which fitted over the pin but were too wide to fit down the hole. As I was scratching my head, trying to figure out what to do next, I noticed something ... the pin had little notches! - three of them. And the spacer was on the middle one (I've attached a picture). That was a nice surprise. So I moved the clip down one notch and reassembled everything, and took it for a spin. The test ride was just terrific!!

No surging. Pulling the choke out one notch while coasting made the bike stumble a little bit (that seems just right).


While test riding I did the roll-off test, and acceleration test, for the main jet. Got back home, and stepped the main jet up to 150. Then test rode again.

There is a noticeable increase in power all the way through, but especially when I open the throttle right up. In fact up around 90km/hr (55mpr) opening the throttle delivers a really surprising amount of torque. I was up to 120km/hr (75mpr) in a blink, and the bike was purring. Also, from a standing start, working hard up through the gears, the bike rockets along. It's not going to lift the front wheel or anything like that, but I did manage to scare myself a little while accelerating out of a wide bend.


So my current carb setup is:

Jets are at 52.5/150
Pilot mix screw is at 1 and 1/4 out
Idle is sweet
Acceleration is strong
No surging at 1/4 to 1/2 throttle
The sound from the Dyna muffler has come to life.

Thanks heaps for the advice guys. Even the smallest details helped from reading through the forum threads. Things like filing the point of my #2 Phillips Head screwdriver before trying to get the screws out of the bottom of the diaphragm, and slapping the gas tank on the right to get it off with the petcock still attached, saved me a ton of headaches

I probably sound like an excited school kid ... well hey ... that's how I feel  

Nice job ! but you should check your mileage ,as it will be a little lower ,but the trade off for good performance is worth it.

zipidachimp wrote on 12/31/16 at 03:05:22:


He's not in the US.....looks like he got the grooved needle as or EPA doesn't reach out that far yet!

Apparently the epa reached into canada, or suzuki doesn't recognise the border.  Or, canadian politicos caved in to a foreign entity, as it's less work, and americans can pay for the research (easy riders!).
I'm veering off topic, so I'll shut up.

I assumed we had the same, if not more stringent, environmental regulations in Australia than you guys have in the States.

I looked it up and apparently we have follwed the UN in adopting the Euro 5 standards. I don't know the details but assume it means are setups are more similar to European than US.

There was no plug on the pilot mix screw on my carb, when I got the bike. I assumed a previous owner removed it when they drilled the exhaust ... perhaps it never had one.