Help, Safari tank vacuum pump not working

I have had the Safari tank on my WRR for three years.  Not sure why, but I decided to test the fuel pick up from the wings.  I emptied out the tank except for some fuel in the bowl and wings and ran the bike.  The vacuum pump that comes with the Safari tank did not seem to be pumping fuel into the bowl.  I am pretty sure it worked when I tested it after initial install (but hard to recall now).  

I pulled the tank and checked the vacuum connections and they look good.  I pulled the vacuum line when the bike is running and can feel the vacuum.  When I called Just Gas Tanks, they were skeptical that the vacuum pump would fail and wanted to know if I had any vacuum leaks that would cause weak vacuum.  I therefore pinched off the line heading from the T-junction back to the cylinder and blew into the line to test for leaks in the fittings.  I could not detect any leaks.  Has anyone experienced a failure with the Safari vacuum pump?  Any ideas what might be going wrong?  

All help is greatly appreciated.  My wife and I are in the beginning of a multi-year trip.  We road cross-country from New York to the Bay Area in July.  We are in the Bay Area until 8/23 and then are heading to South America.  I would love to resolve this issue before leaving the country.

i'm not sure if you've removed the flapper solenoid and actuator system...i removed the flapper and associated hoses/wiring and ran only one hose from the inlet boot (at the throttle body) to my tank connection, this creates a pulse, which is what you need..if you connect downstream into the flapper system, past the check valve (small in-line cylinder), you only get negative pressure, which will not pump...tee in to the hose upstream (closer to the throttle body) of the check valve or remove the flapper stuff (and the check valve) and use that connection...make sure you don't leave any connections open..

On your vacuum pump keep in mind that if either of the wings on your tank run dry and the pump sucks air it will not pump air out of the other wing.  Be sure to pick up vacuum from the throttle body so you get a good pulse.  These pumps are bullet proof I have never had one fail in many years of using them on my bikes and also in karting.

Here is a link that might help.  



Good luck.

Did you ever solve your vacuum pump problem?

I, too, have a Safari 3.7G tank on my WRR.  The vacuum pump worked fine after initial install about a year ago, but I now get what seems to be fuel starvation whenever the gas level gets below the base of the pressure pump.  The bike runs fine when the gas level is above the pressure pump base, so I don't think there are any other bike issues.  However, when the gas level drops, the vacuum pump does not appear to move enough fuel volume to feed the engine much above idle.  The vacuum pump does move some gas, just not enough for an open throttle.

The vacuum lines are not leaking (the vacuum pressure bounces between 5 and 10 inches of Hg at idle).  The fuel pickup lines are routed properly to the bottom of the tank and I've not had any dirty fuel in the tank that might have clogged the pickup filters.  

Just Gas Tanks also told me that the vacuum pumps never fail...

Any suggestions would be appreciated before I go to the hassle of pulling the vacuum pump out to inspect.

if you're sure everything is fine (check and check again) then try to adjust the aim of the hose...i've had to re-tyrap the end once when it fell over and started spraying sideways, away from the pump and the "cup"...try slitting the end of the hose 1/2" to relieve pressure and keep the fuel from spraying too hard at the "cup"

At this point, I've:

• Replaced the Mikuni vacuum pump.
  
• Replaced the fuel pick-up lines for vacuum pump (including filter socks).
  
• Properly routed the fuel pick-up lines so that filter sock is lying flat on the bottom of the tank, in the front bottom corner.
  
• Used hose clamps on all vacuum fittings to ensure no leaks.
  
• Cut a bevel on the vacuum pump output delivery tube (to base of EFI pump) to make sure there was no flow blockage.  This tube is attached to the EFI pump frame so that it's outlet sits right at the base of the EFI pump.
  
• Measured intake vacuum at vacuum pump fitting to be about 200 mmHG at idle (which is in normal range per service manual).
  
• Measured the flow rate from the vacuum pump to be 8-10 liters/hour at idle.  The Mikumi pump is rated at 11 liters/hour.
  

The bike will run when the gas level in the tank is below the EFI pump only at part throttle.  Any attempt to use more than about 1/2 throttle will cause the engine to stumble badly.  I might be able to limp to a gas station, but it's not rideable as far as I'm concerned.

The bike runs fine when there's enough gas in the tank that the fuel is above the EFI pump base.

I believe that the bike ran fine when I first installed the Safari tank a year ago.  (Although, my initial "testing" was probably done when I was just breaking in the engine, so only used partial throttle...). The bike now has about 9000 miles on it.

I've contacted JustGasTanks and Safari (in Australia), and they have no more suggestions.

At this point, I don't know what else to check other than the EFI pump itself.  I don't really want to spend $300 to replace the pump as an experiment (or hack up the pump frame using an aftermarket pump replacement).  

This leaves me thinking that either the vacuum pump flow rate is really very marginal and can't keep the fuel well around the EFI pump adequately supplied with gas when the bike is moving (sloshing gas out of the well), or there is something wrong with the EFI pump.

Any other ideas?  I'm stumped!  Thanks!

Any progress on this?

No real progress.  Iv'e taken every thing apart (yet again) and everything looks good.  Still the bike stumbles anything over 1/4 throttle when the gas level is below the EFI pump.

I am beginning to wonder if the vacuum pump was ever sufficient to run the bike properly when the gas level is below the EFI pump.  Can anyone confirm that the vacuum pump supplied by Safari works well when the gas level is low?  I'm thinking my initial impressions were made when I was still breaking in the bike at very low throttle openings.

If you've got a Safari tank that works, please chime in!

I'll try another round of emails with JustGasTanks and Safari in AU.  The only thing left is a new EFI pump.

Thanks for your help!!!

Have you tried posting on the Megathread in Advrider, or Thumpertalk? Lots of WRR Safari tanks out there...

I've used those sites in the past, but not recently. I'll try again. I'm not happy chasing down issues with an aftermarket item when the WRR runs great without it...

Thanks.

Yeah, that sucks. It sounds like you've put in some time... bummer that the problem is still there, but you have definitely narrowed down the possibilities...

At this point, because you've put in so much time and effort, it would make sense to go ahead and purchase just the pump/filters. I haven't taken my assembly apart, but I hear getting a set of micro picks makes releasing the plastic tabs much easier. That is a low cost option, and at least you'd be able to check-off that last possibility....

Bike runs flawless until the level is below the EFI pump?... I suppose that it is possible that being submerged makes thing easier on the pump as opposed to sucking up the fuel from the intake tray/base...

I saw your post on ADVrider... hopefully you get some info there. If info is slow in coming, I'll give your post a "bump" after a bit...

the aftermarket tanks sure have a need for attention...
i've run my 4.7 gal IMS for a few years now and have had to figure out things on my own (just because when things break down, you have to know)..
as you've discovered, the mikuni pump is very bomber... the key is to supply your fuel injection pump with enough fuel to operate.. air will cause hesitation and eventually failure of your pump.. if you have to use a Y-fitting to split the pressure and have two lines from the vacuum pump to the "cup" or re-mod a "cup" then so be it..I've stated before that i've had to re-organize the delivery end of the vacuum pump, adjust the aim,etc.. operating conditions make it that fuel will slosh around, try to keep it in one place..I've even had issues when one wing went dry before the other one, leaving me to tip the bike on the side of the road to even out the remaining fuel.. i think even someone mentioned using fuel tank foam (to stop the sloshing)...

I've decided to add a 2nd vacuum pump (per 10Cup's recommendations on the ADVRider site). This should provide more fuel flow to the EFI pump and reduce issues with one lobe of the tank running dry before the other.

However, it does nothing to help prevent sloshing of fuel away from the EFI pump base while riding over rough terrain. If this remains a problem, I may try to create some sort of deeper "cup" around the fuel pump base to contain the gas (something 1-2 inches high). This will make the bike more dependent upon the fuel pumped from the vacuum pump(s), but it should help reduce fuel starving.

Ultimately, though, you're right; these aftermarket tanks are marginally designed! It's irritating to spend $ on a premium tank, and then have all this hassle.

BTW: JustGasTanks recommended NOT using fuel tank foam (unfortunately, I can't remember why...).

A guy on ADVrider added to the pickup walls. He used an HDPE baffle.
Post #50835 from the Mega Thread.

Plebian, Thanks for the pointer to the baffle post. I will likely try to add this, too. I wish HDPE was easier to bond or seal while floating in gas!

Epee wrote:

Plebian, Thanks for the pointer to the baffle post.  I will likely try to add this, too.  I wish HDPE was easier to bond or seal while floating in gas!

Maybe send a PM to anyone that has posted about similar issues in the past. Even if they don't have the bike any more, they will probably be more than happy to let you know how things turned out. I've had good luck doing that.

What a pain... As you said, sucks to have an aftermarket part ruin a perfectly good running original. Not to mention have the aftermarket part producer insist that the problem is on your end.

I was initially looking at a Safari, the 4.7 IMS is too big, but am now thinking the IMS 3 gallon, plus carrying extra fuel when needed, might be the way to go. Just bought a Mosko R40 bag system which can carry 4 one-liter MSR bottles if need be. I like the radiator protection provided by the big tanks, but don't want to add headaches my happy moto pastime.

I installed a 2nd Mikuni vacuum pump.  The 2nd pump did the trick.  I can now run full throttle with the gas level in the tank below the EFI pump.  

A secondary benefit of the 2nd pump is that you have separate pumps for each side of the gas tank, so you get all the gas in the tank (not limited to the side that empties first, resulting in air being sucked from the empty side).  

10Cup (AdvRider) provided a great instruction guide for the 2nd pump installation.  It's quite straightforward.  Thanks 10Cup!!!

I have not built a baffle around the EFI pump yet.  It may not be necessary at this point.  I did purchase some HDPE sheet and am experimenting with bonding the sheet together, and to the EFI pump housing.  HDPE sheet is a pain!  It's easy to blow holes through thin sheet trying to heat weld!  It looks like Scotch-Weld DP8010 or DP8005 adhesive might work on these low surface energy plastics.  The EFI pump housing has a couple of features that will make adding a baffle that does not leak quite difficult.  Using an adhesive to seal the bottom edge of the baffle is almost certain to make it impossible to replace the high pressure pump or fuel filter in the housing, if any future maintenance is required.  I'll post updates on my experiments.

Thanks for everyone's help.

Thanks for posting your results/solution. Too many issues get left hanging... Glad you are up and running.

Epee wrote:

I installed a 2nd Mikuni vacuum pump.  The 2nd pump did the trick.  I can now run full throttle with the gas level in the tank below the EFI pump.  

A secondary benefit of the 2nd pump is that you have separate pumps for each side of the gas tank, so you get all the gas in the tank (not limited to the side that empties first, resulting in air being sucked from the empty side).  

10Cup (AdvRider) provided a great instruction guide for the 2nd pump installation.  It's quite straightforward.  Thanks 10Cup!!!

I have not built a baffle around the EFI pump yet.  It may not be necessary at this point.  I did purchase some HDPE sheet and am experimenting with bonding the sheet together, and to the EFI pump housing.  HDPE sheet is a pain!  It's easy to blow holes through thin sheet trying to heat weld!  It looks like Scotch-Weld DP8010 or DP8005 adhesive might work on these low surface energy plastics.  The EFI pump housing has a couple of features that will make adding a baffle that does not leak quite difficult.  Using an adhesive to seal the bottom edge of the baffle is almost certain to make it impossible to replace the high pressure pump or fuel filter in the housing, if any future maintenance is required.  I'll post updates on my experiments.

Thanks for everyone's help.

Would you be able to pass along the link to 10Cup's instruction guide? Cheers

chriswh86; 10Cup emailed me a Word doc with the instructions.  PM me with your email address, and I'll send you a copy.