test your petcock, hit the link below, go down to petcock, 1st item.

sounds like you don't have enough air, a wet filter will choke it.

check your crankcase for a high level of oil
if so change it as you might have gas in your oil.
gas thinned oil don't work so good.

JohnD wrote on 08/16/13 at 20:28:07:


Now me, I am the BAD PETCOCK expert here on the list and I do believe you have one.

John D, I just gots me one small question to ask you about the situation you discovered in your air box.

What would have happened if you had a spit back event when you were cranking your bike with that half a cup of gasoline down there soaking half of your air filter element with liquid gasoline?  

(think about your airbox volume sitting there just plumb full of gas vapor/air mixture with a gasoline wetted wick sitting there all ready to go)

Can you say  "Boom !!!     Whooosh ....."

Now this "go up in flames" thing has NEVER happened yet on a Savage, <READ DOWN BELOW PLEASE FOR ADDITIONAL INFORMATION FROM BERT'S FORUM> thank goodness, but we have had an easy half dozen people report what you just reported, a bad vacsucker petcock dumping gasoline into their air box.   We have had more people than that say they got gas down into their sump.
(logically they got it in their airbox too but just didn't realize it)

The moderators still are debating on what stance to take concerning getting pro-active about telling people to remove the prone to fail stock vac petcock and I just saw two simply suggesting you test yours although they both knew durn well what the test should show.  

What's scary to me is that newbies in general have always shown a fairly common inability to understand the Serowbot Petcock Test and they commonly just do part of it and then they mis-interpret the information they do get from the test about 30% of the time.  

And the most common misunderstanding of all is the ABSOLUTE NECESSITY of blocking off the vac line with the golf tee and I can't count the number of folks over the years who put it all back the way it was before actually completing the test routine because they didn't understand the test, didn't do it correctly and thought it was "too much trouble".

Me, I take a much cleaner more draconian stance.  Gas in the airbox or gas in the sump, TEAR THE STOCK VACSUCKER OFF OF YOUR BIKE IMMEDIATELY.   Screwing around with it for the 1-2 weeks it takes to do the Serowbot Petcock Test correctly is a VERY BAD BET on an item that has ALREADY failed and dumped dangerous amounts of gasoline into your airbox or into your sump.

Now, is this fair to you, John D, who are smart enough to do the test correctly?  No, it isn't -- but of the next five newbies faced with the same situation 2 of the group will be the ones I am talking about.

But then again, that's just me --- you jest go ahead and ride that bike around for 1-2 weeks and Lord willing, you won't get any spitbacks through your intake valves during that period of time until you finish the test .....  or worse yet, you can procrastinate for a week or so before you even do anything.

(Yup, that's commonly what some of them actually do, absolutely nothing, for weeks and weeks and weeks until they get 'round to it).

Now that we've scared John to death... (on his first post ever)...

Here's link to the test.. it includes info on the Raptor petcock swap... ...
Test your Petcock,.. don't just turn it to Prime..

Serowbot wrote on 08/17/13 at 17:52:07:


Are you holding out some hope that he has a stuck float valve assembly?   If so, it is still a vac petcock failure as there should be no fuel flow to the carb bowl if there isn't any engine vac suction to cause it to flow.

And the response of "do the test" really doesn't play for much as it doesn't include any testing of the float bowl assembly for sticking (other than whacking it sharply with a big screwdriver handle that I stuck in there several years ago).

Dave has offered to help rewrite the whole mess to make it clearer and more concise (so the kiddies will actually go do it) and please also to include all the stuff we have learned over the last 2 years.  You and Dave might want to be about that as you are now in a foot race with the very sluggish glacial response time of NHTSA.

Serowbot, early on you reported one of your own personal Savages leaked gas out on the concrete too.  

It's gasoline, it poses a fire risk when it does that -- don't you think so?

Like Serowbot, how many of us have had a petcock fuel leak, either on to the concrete, into the airbox or into the sump?

Just respond briefly guys, I am sure we can collect enough incidents to get the Savage ls650/S40 included into the NHTSA drop down lists for some proper official data collection.


================


Suzuki has better functioning vac petcocks that go on their better bikes -- and I bet NHTSA would tell them to put "the good one" that fits properly on on our bike for free if we just all reported our issues with the current vac petcock to NHTSA.

An additional fuel shutoff that is inline is a good idea but doesn't solve all of the failure modes with the stock petcock.

Given the low mileage at which many of them fail, I would have to say there are manufacturing defects or extremely cheap (not meant to last) manufacturing issues. Either of those situations is a manufacturer's issue and should be fixed either voluntarily or through a forced recall.

Before mine failed, I noticed the fuel in the line pulsating while the engine was running like it had a vac operated fuel pump. Mine was 26 years old and 23k miles at failure. It failed by letting fuel through the diaphram into the vacuum line but only with the engine running. No leaks or problems when sitting. From what i've read, it seems most don't make it to near that age and are usually lower mileage than that also.

Change the petcock and save yourself loads of problems.

After years of answering all the endless questions that all turned out to be the sorry vac petcock in the end, I have reached the point I will be offering the NHTSA safety issue reporting page to those newbies who have issues that warrant its use.

Suzuki and the other bike manufacturers ARE AWARE of these issues.  They are all hunkered down like turtles in their shells.  None of them have done anything voluntarily, each have had to be forced by their Forums (that's us) to deal with it unwillingly.   The lever that was used was NHTSA issue reporting.

Step #1 is for enough people to fill out the on-line form when they have a gas leaker vac petcock (and we have a half dozen air boxes a year, but it seems to be growing larger as the bikes age out).

People who have gas in sump episodes should fill out the NHTSA form as well, contamination of your oil (thinning) has been associated with engine damage (piston galling & ring sticking & seizure).   This too is a safety issue as when your engine abruptly dies in traffic that is dangerous to you physically.

Suzuki should do a recall campaign and replace the bad OEM petcocks on any stock machine of any year model.  

Modder/Bobber/Ryca people have likely already replaced theirs with a Raptor just to get the increased gas flow at high speed that their modding efforts require, so they are likely already done already.

We are going to have to start telling folks step #1 on the performance mods list is to replace the stock vac petcock with a Raptor.  If you don't do this the newbie modder person is doomed to complications in tuning, etc. that they need not suffer through -- good reliable gas supply makes all tuning easier.

If your bike has any mods to the airbox or air filter I would not report your issues to NHTSA on the report form.   You screwed around with the stock vacuum level when you did those mods (or Suzuki will so contest).  

And I would have to concur, except that true leakers are a failure of the diaphragm itself and I can't really make that leap of faith that your airbox mods caused that to happen.   It definitely caused all the trickle of gas performance issues though, I can concur with that thought completely.

With the coming of electronic fuel injection the problem of vacuum petcocks will go away all by itself. I suspect all the makers are counting on this. I am also sure they will not replace a vacuum operated petcock with a manual one of any variety, both for operator convenience and safety. They may be forced to use an electrically-operated petcock instead of vacuum, which will avoid the issue of fuel leaking into intake manifolds and running somewhere else. I also suspect they will decide rubber/plastic parts have a limited lifetime (note the recommendation that brake lines be replaced at four-year intervals), and if they fail after that time it is not their responsibility.