tested or replaced your petcock?  that seems to be a sore spot on these guys.  i went and replaced mine with a raptor 'before' it gave me any issue.

You could try the Serobot test to check your petcock, just post an new thread, Serobot test". The Raptor petcock is cheap enough anyway, you will need vacuum plugs and try and ride down to resrve before draining the tank.


OF     Serowbot Test is here, very useful information comes from this test, literally cuts the world of possible troubles in half it does.   Any "fuel related" problem should start out with a Serowbot Test (wait for the new person to come back with the results before going on to other things -- half of them won't be needed -- and which half is real is always good to know)

http://suzukisavage.com/cgi-bin/YaBB.pl?num=1251932429/1    


New persons with issues should stay with the ONE THREAD approach, this way the helper persons can read the entire history of the problem(s) before responding with the help.   If the new person is keeping multiple treads going, part of the info we would need is NOT THERE for us to read.

Don't ever tell a newbie to fragment his stuff into multiple threads ....
It makes helper persons and moderators start looking like this

   

& did you use the gauge on the mitivac to check how much vacuum the engine creates & thenb subject the diaphragm to that amount of vacuum or did you just use a tool that creates vacuum & suck the diaphragm over with it with 5 times the vacuum the engine makes?


YOu gotta know what vac the engine makes..

wernwilk wrote on 10/02/12 at 22:36:20:



Me, I'd suggest reading the tech thread that you were provided and then doing the test that was specified.

The gist of which was to put the cast in place arrow on the lever pointer pointing towards PRIME and set the plumbing up like this:



Why, because it is a specific test that does a lot of things and tells us a lot of information.  

You can do anything you want with a mitivac and as Justin points out, you have told us nothing because you didn't do the test as specified.  You might have run the risk of overextending your diaphragm by too much suction (yup, it has happened even when people suck on the line with their lips and lungs) and causing yourself a possible new issue with your vac petcock.

Try reading the thread   http://suzukisavage.com/cgi-bin/YaBB.pl?num=1251932429/1  and doing the test and getting back to us with the results.  

Give you a clue, you either say "nothing changed" or "it ran better", and you have to run it in Serowbot Test Mode for at least two gas tank fulls of gas set up like the picture before you make any judgements on "same or better".  

This isn't a one shot fast test.   Fuel starvation events are occasional and take several things happening for them to occur -- so the test for this takes time for the same several things to occur again and again (weeks of chances for it to all line up again and again).

And please do follow the pointer arrow to find PRIME, on some petcocks the arrow is reversed to the overall direction of the lever (lots of years, several petcock suppliers over the years, some petcocks are marked differently).  
 
 

You must rejet with K & N no question. Too lean and will hurt your engine if not addressed. I have one on my S40 and one on my VOL. Dodge truck also but that's a horse of a different color.

Update,
Today I carefully stripped and inspected the gas cap...all seemed well and squeeky clean.

I also tried a mod I heard about a while ago which was to remove the plastic washer from the top of the jet needle...this definately helped a little but there is still some surging.

so, from here I will have to decide whether or not my friend should either;
- Get a jet kit, (dyno or other)
- Leave the jetting and get a $50 or so OEM air fliter

MORE WORRYINGLY - the bike died on the ride twice on the freeway..about 6-7 miles in on the freeway with the bike at almost WOT it died, as though the gas had been cut off completely.
I clutched it and once stopped I removed the gas cap and listened for any hiss...I could not tell because of the road noise but could not hear any.  I tried the starter and it fired right up.

Then after the next 4 miles or so it happened again - this time after rolling to a stop I tried the starter without removing the gas cap and it fired up and ran again straight away.

Could it be the emissions system that is doing this?  If so, how do I eliminate the system - I assume I cut the pipe from the tank low down and let it hang like a normal breather....then I assume I disconnect the purge side of the system from the carb and blank of the carb intake nipple?

Or does anyone think it could be a coil breaking down under load - it would seem odd that there is no cool down time needed for the bike to start up again!!

Any and all help very much appreciated.  The DYING of the engine on freeway is by far the priority for me at the moment.

Thanks.

Disable the clutch and kickstand safeties and see if it cures the problem.

or keep your foot off the kickstand.