So I installed the Raptor petcock. At the time, I was not aware of ANY issues related to the fuel delivery on MY bike. The bike ran well, and all was good.

Installation of the new petcock was straight forward and without issue. I did remove the seat and loosen the strap that holds the tank on to better aid in removing the old petcock. I also DID purchase a vaccume block off, that seemed to fit perfectly ( $2.46 for a pack of 6).

On my two 10 mile rides. I have noticed a difference in the bike. Now understand I am not very knowledgable in super technical workings of carbs.  I do  not think that my bike ( the carb) was starved for gas, or that the delivery of gas has now changed significantly from that of th stock petcock, however, there does seem to be a change in how the bike runs. If it is NOT due to simply fuel delivery, then it must be due to the vaccume change.

I cannot say that change is GOOD or BAD... its just different. The bike seems to be quicker to rev up and slower to come back down off the revs. Rather like a hyper active kid, that wont settle down. Perhaps a bit more pep, but with it a less control of the rpms.

My theory is that I have plugged a small vaccumm leak (which was desgned in) and now that carb is much more efficient at drawing gas through the various circuits. The unplanned for increase in vaccume may mean that my carb will need adjusting, mostl likely to lean it back out a tad.

Comments and suggestions welcome.

 
With the stock vac petcock always fighting to deliver the requested gasoline flow, you always had a partially depleted float bowl level in the past when you were running hard.

Now your float level is always sitting right at the cut off line and you get "the correct metered gas amount" at all throttle settings no matter what you do.   This is especially noticable when you whack the throttle open and ask the bike to GO !!!

Yes, your bike does run better with the Raptor, especially if your bike is performance modded.

RanDaMan wrote on 08/27/12 at 10:54:59:



Yup, you can quit stalling & procrastinating over your faulty stock vac unit and go get you a Raptor for $16 shipped and INSTALL THE SILLY THING.

Suddenly your bike works much better -- that's a performance mod isn't it?

 
Before we were told that the suck went nowhere and no air moved, now they are admitting .....


"it's a leaky rubber ducky"


Weeeeee !!!!   Ain't that fun?


       


You guys need to help me ask the next dumb questions ---

"Where does the air come from then to fill the leaky rubber ducky?"  
the rubber ducky is solid, air goes past it, not in it
"What path does the air take?"  
from the intake, to the vac line, past the rubber ducky, to the diaphragm
"Is this a lot of air leaked over time, or just a few cc's worth?"  
the chamber in which the diaphragm lives is small,
"So, the leakage to release the diaphragm and cut off the gas flow is intentional, right?"
yes, otherwise you'd have a lot more problems with gas in the crankcase
"What if there is just a little more leakage than intended, could this give us a few of the symptoms we see of gas cutting off when we don't want it to -- like when we are idling at a stop light for example ...."
yes, for the case of the sudden decel from superslab to stop, a quick shutoff of gas will make the problem worse
Have some fun with it, Verslagen and Lou are actually experts on these vac petcocks and they actually can answer questions like these if they are asked.

Actually the opposite is true, the micro squids use a resevoir on their intake to boost performance, probably around 10 oz.  

So the ounce in our vac line to our 650 lung is inconsequencial.

How about posting a part # (or #'s) for the Yamaha Raptor petcock.
I'm not having any trouble with my stock one, but would like to order one when convenient so as to have one on hand when needed or accessing the spark plug - whichever comes first.

LoL Routy,  just having the ease of clearence from the Raptor was enough for me to spend $14    

 
We have all been watching for the first "fuel in sump" episode that resulted from a Raptor converstion.  And by all, I mean all of the folks who have converted over to the Raptor, so it isn't just me or Routy looking.

We have had two persons (who both admitted having bad float needle valves as a pre-existing condition before they put the Raptor on) who had gas in the airbox still after their Raptor conversion.  Both immediately replaced said needle valve and fixed their issues.   Gas in airbox only, none in the sump according to the two people involved.

We have ONE (1) person,  Joe F  who says he dropped his bike and had fuel leak out because of the Raptor, but he has not come back to provide any of the details.  He has been PM'd, but has not replied as of yet at all.   Routy needs to get up with the man and get him to talk to us,  as we all really do want to know his story.

Eventually, we will get a gas in sump episode.  Somebody will park a bike at an odd downhill angle or have it fall over and lay in the parking lot for a few hours or some other set of odd circumstances will make one happen.

It's been several years now, but it hasn't happened yet.  

So the watch continues .....


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


Question for Routy,

If 50% of the people taking the last poll (21 of them)    http://suzukisavage.com/cgi-bin/YaBB.pl?num=1345820468/45#45    all listed bad vac petcock symptoms and flat said that the Raptor made all the bad stuff stop --- are all 21 persons delusional?


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


 
Cheap Chinese LONG DROP PETCOCK for $16 shipped

http://www.ebay.com/itm/Right-Hand-Suzuki-LTZ-400-LTZ400-Fuel-Gas-Petcock-Pet...





Looks like folks have started peddling the Chinese rip-off of the long shank Raptor petcock fairly cheaply --
of course somebody has to actually order one and try it out before we will all KNOW it fits up properly.

Watch out, they are saying it has a RIGHT HAND gas nipple location which would be correct, depending on if you really are standing beside the left side of the bike looking straight on to the side of the tank.



Still, $16 with shipping is a lot better than Yamaha pricing of $24 with $7 shipping on top of that.