Hi everyone,
Been browsing through some interesting topics on getting the S40 riding at interstate speeds.
Mostly rejetting, and grinding out the exhaust port, was said to improve mpg and top speed.

Almost every topic I see, is about the top speed of the S40 being limited due to:
1- vibrations
2- lack of HP
3- too high rpm.

Vibrations seem to appear around 80mph, and merely an annoyance, not a limitation;
But they do hold people from going any faster.

Essentially lowering rpm by 10%, would move up the vibrations by almost 10mph.
Number 1 can be solved, by regearing the bike, lowering rpm.
I wanted to know if there is a front pulley for sale with 1 tooth up from stock, that fits?

I'm not too fond of the pictures I saw of the chain conversion, unless a chain guard can be used. The stock one preferably, even if the rear sprocket is 3/4 the size of the pulley.

To make a re-gearing possible, the engine needs more hp (for top speed).
I read about someone drilling out the exhaust ports with a dremel. It should increase hp, and mpg.
Add a more free flow exhaust if necessary  (or in some cases, replace the air filter with a more modern one), and compensate with a slightly bigger main jet, for a richer AF mixture. Should give at least one to 3 extra hp, which is 10%.

Any other suggestions, concerning pulley system, or a nice looking, affordable chain kit with chain guard?

Also, any ideas about making the engine vibrate less by balancing it out?
I once saw a video of a guy who would just drill a .2" by .2" hole in the counterbalance of his motor; which reduced the weight of the counterbalance, and made the engine run smoother.

From your post, I can't tell if you've ever rode a savage.
Everything you're inquiring about is subjective.

What is your experience with the savage?

Serowbot wrote on 01/28/16 at 08:50:47:


Never thought of it that way - but you are correct.

And the last 4 horsies continue to cost.....as the Wiseco requires the use of premium fuel.

"...far smoother as-as than a lot of thumpers...."

Before I bought my new S40, I rode a Yamaha SR400. It only took 6 blocks for me to realize that little "butt-buzzer" wasn't for me.

MeeLee wrote on 01/28/16 at 06:41:14:

Most practical option, is a bigger bike --  Serowbot
The Savage will never be a silk purse.  IMHO:

On an Interstate trip from LaLaLand to Kentucky...  vast majority of traffic cages were running 5 mph over the speed limits, commercial traffic ran at the speed limit, and the motorcyclists ran 5 mph under the limit.   A stock Savage can comfortably run 85 mph.  At 70 mph the Savage is doing about 40Hz, and for me the vibrations are relaxing.

I had no problem doing 500+ miles a day on the Savage.  However, if you want to cruise an actual 80 mph you need a bigger bike.

Even BMWs aren't vibration free...or at least the old air-cooled models weren't. I owned 800 & 1000cc "air-heads," the 800 being a bit smoother, while the 1000 had "longer legs" (higher gearing) for higher speed cruising. Careful valve adjustments and carb balancing worked wonders.

That being said, what vibration they had was a high-amplitude/low frequency vibe as opposed to a Japanese UMJ 4-cylinder low-amplitude/high-freq "buzz." Of the two, I'll take the former.

I haven't been on a long, highway-speed cruise on the S40...still carefully breaking it in...but initial impressions tell me that it will be good for 60-65 mph cruising without undue vibration discomfort.

http://www.vintagepaperads.com/1987-Harley-Davidson-Motorcycles-Ad--Comforts-...

I have a full chain conversion for sale, lowers rpm at higher speeds. Stock belt cover works with the chain, I just removed the loer cover.

Pm me if interested

Seriously, You want to cruise at 85mph all day and you bought a Savage??? Your kidding right? Or do you mean 85k? Is it April 1st already?