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Message started by stewmills on 11/07/15 at 22:45:28

Title: 140 main jet?
Post by stewmills on 11/07/15 at 22:45:28

Ok, so the bike has been running what I consider great for about 3 years. Had a mechanic do some jetting on the bike when I first got it because I was too scared to get in there at the time (not anymore). So I finally got back into the carb today and went ahead and looked at the jets for argument's sake while I was cleaning the carb and I swear it says 140. Can I really be running that low of a jet and it perform so well? Seems that most of what I see on here are 145, 150, etc.

I am in AL at about 800 ft. My gas mileage when I last stopped recording it was 45-50mpg with most of that semi-city miles at 35-55mph.

I don't feel compelled to dig in there and mess with it, just curious. I have run the dragon and NC mountains hard as heck and get around town here pretty well, so I guess it's all good?

Title: Re: 140 main jet?
Post by Dave on 11/08/15 at 05:19:01

Here are the stock jetting specs.

http://suzukisavage.com/cgi-bin/YaBB.pl?board=tech;action=display;num=1098869040

The main jet on most models was supplied as a #145, and the pilot jet was either a 47.5 or a 52.5. The California models were completely different and had different jet needles (pointy needle sticking down frm the slide) and needle jets (part the main jet screws into) - but they ran #125 main jets and 47.5 pilot jets.

The main jet really comes into play when the throttle is 1/2 open more, and the majority of your riding sounds like you don't use that throttle setting much. At the Dragon your elevation could have been up near 2,000 feet at the top, and on the Cherohala Skyway you could have been up over 5,000 feet, and the smaller main jet could have been better at those elevation.

My riding at home is about the same as yours, and I have re-jetted 2 bikes for this altitude, and the one with the cam/piston/DYNA muffler preferred a #150 main/#50 pilot and 2 washers on the needle, the other stock bike preferred a #150 main and #52.5 pilot and 2 washers on the needle.

If your mechanic installed a DYNA JET kit.....I believe the sizes of their jets are stamped differently - but I don't know if the number on their kit is a #140.

If you want to try a #150 main jet, you can change it without having any effect on the idle circuit, and it will only negligibly affect the operation of the needle jet, and mostly at higher throttle settings. If it runs better at full throttle with the #150 than the #140, then the change is better. Find a place where you can get into 5th gear and apply full throttle for a run from 50 - 80 mph or so.....find some road signs or landmarks to start the full throttle run at the first landmark, then find another one to use when you reach the limit of your bravery or the bikes terminal velocity.....then change the jet and do it again. The "fastest jet wins"!

Title: Re: 140 main jet?
Post by stewmills on 11/08/15 at 08:48:27

I looked back at the paperwork and it was a Dynojet stage 1 kit, DJ3107. So that probably explains a little of the variance in numbers...maybe?

Anyhow, it runs great and the guy that did the work was an older motorcycle guy and seemed to know what he was doing as far as tuning it, etc. It will roll off pretty good if you lay into the throttle at 55mph, plus I am a little guy at 5'6" and 165lbs so that probably helps too.

Wish I knew what I know now...would have saved that $250+ but he did some other things as well so it was probably worth it for me not to tear the bike up as a newb. This forum has saved me that 10x over the last 3 years so it's all good!