Bad Fuel Pump? Viper

02ViperMody44

Life Member
Joined
Feb 11, 2008
Messages
202
Age
49
Location
Uitca, NY
Bad Fuel Pump Or Startron Cleansing

#$%&* '02 Viper SLP's etc.... Just filled up with 8 gallons of '93 octane on the trail, went 7 miles, and while maintaining 40-45 across a lake, my sled all of a sudden lost power, no banging or erroneous noises, just like someone turned on my kill switch. Would not throttle up. I killed it, waited 10 seconds and pulled it and it started like there was no issue. I drove it and then put some power to it, and it was like there was no problems...but I spoke too soon. Same thing happens, as if it was running on a couple of cylinders, until it sputters and dies. Wait a little bit, will start, run for a mile or so, and then same thing happens.
Checked compression- all good. Checked coils-all firing. No light flickers, tach, brakes, everything appears to be fine. Recent rebuild, seals, rings. When trying to start it right after it dies, it would initially start up, but after awhile I would need to choke it(well warmed up @ 133-145degrees F). Initially needed half choke to get it to run, then full choke to get it to idle, won't propel the sled forward w/ throttle, only idles up a little and then it will stumble and quit. Carbs cleaned again-nothing. Disconnect fuel line from tank, and fuel pours out uninhibited. Sealed up the vent line on the bottom of the pump-didn't help. Pulled pump apart, and seen that the diaphrams were bloated a little, and one was actually pressurized. When taking the diaphram off of body, it actually hissed when relieving air pressure. Put it back together, and tried it and it would actually run less distance than before, wouldn't even stay running with the choke on now. Also, did put a slight nick in the diaphram when pulling it apart.
Hoping that someone else may have had a similar episode, to compare to. As I have a used pump to try, and the sled is an hour and a half away. :itchy:
 
Last edited:

More info....Were you riding before you filled it up or was it right in the morning ? First ride of the season or not. If it was in the morning and it was cold. maybe the fuel pump froze. Theres a screen on the pump so the diaphragm can "breathe" These get ice in them and then it don't pump.
 
Had ridden apprx. 90 miles earlier in the week. Logged 60 miles that day, before filling up on the trail, and it was running fine prior to that. Was breaking trail across a lake when this happened. Apprx. 15-20 degree F out. Taking a different pump with me to see if that makes a difference.
 
does sound like a frozen fuel pump which was common on vipers, when you put a new one on, place a thick peice of rubber on the studs first to space the pump off the tunnel a wee bit, this will keep the water from puddling up and freezing .
 
Well, tried a diff. fuel pump and I have the same outcome. It did already have it breather sealed from the bottom, and I have washers under it to keep it up directly off the tunnel. I replaced all the fuel/pulse lines. It started fine, idled fine, but then after it was warmed up, and I was squeezing across Lake Pleasant, it started to die, it would catch, and then start to fumble. If I let off the gas and it hit again, it would somewhat catch and then falter. Could the Stator do this? I am not seeing any kind of dimming or tach issues, or am I looking at a bad case/crank seal wreaking havoc on my pulse line to the fuel pump? Seals were replaced w/ Yamaha parts last year, 1500 miles ago, and no issues last year.
 
Last edited:
Hey Rick, Ok, sounds like your good to go on the fuelpump issue. let me ask this since you said it acted up after you got gas, is there water in the tank?


if not: does it have any flutter in the tach or anyhting with it running if you play with the headlight dimmer switch?

could possibly be bad sparkplug boots or a rubbed thru wire harness .
 
be certain all carbs are venting correctly.... an obstruction on the carb vent cct. will drain the bowls dry and make it feel like you ran out of gas... once pressures equalize and the bowls can fill correctly again, (after a few minutes), you're able to start.

note..

this condition also creates a lean condition just before stalling so get to the bottom of it soon, should this be your problem... tj
 
mrviper700 said:
Hey Rick, Ok, sounds like your good to go on the fuelpump issue. let me ask this since you said it acted up after you got gas, is there water in the tank?


if not: does it have any flutter in the tach or anyhting with it running if you play with the headlight dimmer switch?

could possibly be bad sparkplug boots or a rubbed thru wire harness .

Well a buddy w/ me got gas AFTER me and his stock Polaris 600 Dragon no issues. I was running Startron, 93 Octane and Lucas Octane boost. Was going to buy the black bottle of 104, but the Advance Auto I was at, their bottle on the shelf had a contest flyer attached, where the entries had to be in by MARCH 31st, 2004!!!, so I steered clear. At the Yamaha Dealer in Speculator, BTW they really accomodated me to attempt to fix this on the spot, they pulled this contraption out that pulls fuel from the bottom of the tank, and they said it appeared to be straight fuel, as they did not see any water/separation. They also cleaned/checked my carbs and they said they were spotless, as they were cleaned 140 miles earlier, at start of season. I turned off the hand warmers, no dice. High beams/low beams doesn't affect my situation.
I've changed the Fuel Pump no difference. Tried a different stator-no difference. Tried different coil pack-no difference. At the Yamaha dealership they said my compression was good on all three, but I did not get a P.S.I. number from them though, and they only pulled it three times per cylinder, I thought you generally did it more times than that, but I'm not a mechanic by trade. I'm going to borrow a friend of mine's testor and get a reading when cold and warmed. He works on sleds. Coming to the conclusion that maybe a stuck ring or more/worse. The only thing left is a CDI. I run normally 135-145 degrees engine temp. I am running 165 mains, and the needles are at 4 clip. Less than 2000' elevation. I have an intact air box, and the carbs are vented to the box. I will check the venting lines for obstructions though.
I went for a ride after doing the stator, coils, and when it started to act up, I killed the motor and pulled the plugs. PTO/Center the plugs porcelain appeared dry, along w/ the electrode tine, the Mag seemed to have a sheen to it, as if it were some moisture on it, along with the tine appearing the same way. I was riding down a trail, and opened it up, which it pulled fine to 8700rpms, then while cruising, it starts to feel like it is coming down, and if I throttle it, it sounds like I have the choke on, or a piston is not firing, but then it will come back on, but then it will get progressively worse, whereit won't come back. If I choke it, it does seem to effect it in a good way momentarily, but then that stops effecting it also, where it just starts idling down, regardless of the throttle. CDI anyone??!! Don't want it to be an internal thing. Shouldn't be long now. #$%&* :EXER:
 
Last edited:
TJ500 said:
be certain all carbs are venting correctly.... an obstruction on the carb vent cct. will drain the bowls dry and make it feel like you ran out of gas... once pressures equalize and the bowls can fill correctly again, (after a few minutes), you're able to start.

note..

this condition also creates a lean condition just before stalling so get to the bottom of it soon, should this be your problem... tj

Sounds kind of like some of my symptoms. Where exactly is the carb vent circuit? Are you referring to the lines that are running criss-crossed along the back of the carbs? or is it inside the carbs?
Thanks
 
wow, you did a thurough job changing sll the stuff out, yep, I have to agree its either a cdi or wire harness issue, nothing left! hang in there youll find it.

Anyone around with a viper you can swap out a cdi box with to try?

when you change out the box check the wires carefully on the footwell and see if theres any chaffs in the wire.
 
When they cleaned the carbs, did they clean the filters under the float needle and seat?
Also check to ensure that the fuel tank vent is not kinked, sqeezed or plugged.
 
mrviper700 said:
wow, you did a thurough job changing sll the stuff out, yep, I have to agree its either a cdi or wire harness issue, nothing left! hang in there youll find it.

Anyone around with a viper you can swap out a cdi box with to try?

when you change out the box check the wires carefully on the footwell and see if theres any chaffs in the wire.

No I'm all out of local parts on hand that I have free access to. I am going to have to purchase the CDI, preferably used from a local dealer/salvage yard. Woud a CDI affect the firing when I put the choke on, or are you leaning that it is going to be internal?
 
sideshowBob said:
When they cleaned the carbs, did they clean the filters under the float needle and seat?
Also check to ensure that the fuel tank vent is not kinked, sqeezed or plugged.

I don't know about the filters under the float needle and seat, I was standing over my sled in the dealers garage, trying to rationalize whether to spend the $15K on a new sled that I can use for a month and a half, lately, where I live. I will check tomorrow. I will check the vent lines over the tank, but the dealer thought about that and there was no pressure sucking or otherwise when opening the gas cap. I actually opened it up when my situation arises, thinking of the same thing.
 
Rick, I have a known good cdi to send to you to try, send me your information.

I dont think its a carb issue because you wouldnt have already been able to ride the sled for 80 miles the first time and then more without the vents and such being a problem, but sounds more like a intermittant spark or timing problem. if it has compression in all 3 cylinders then its likely not internal.
 
mrviper700 said:
Rick, I have a known good cdi to send to you to try, send me your information.

I dont think its a carb issue because you wouldnt have already been able to ride the sled for 80 miles the first time and then more without the vents and such being a problem, but sounds more like a intermittant spark or timing problem. if it has compression in all 3 cylinders then its likely not internal.


PM Sent.
Thanks
Rick
 
check for wire rub, i have at times had stator problems that would do as you say, about the choke helping a little then fading, but still i have had problems simuliar to this be fuel in the bowl problem (not enough), would start run, die, restart, idle all day, give throttle run then die restart exc.if you would let off throttle before it totally died it would return to rough idle.
 
Well I pulled my head, after doing a compression check. At cold, on this particular tester I was using, it was showing 110 PTO and 115 center and 115 Mag. Rings are 150 miles old, so I just don't know if it was the gauge giving these low readings, as I would have expected higher. Pics of my pistons/Head. My mag seemed to have little carbon, as if it was running really rich, and washing it all off/ not igniting the fuel. What think? I also sprayed Starting Fluid around the whole motor, and the idle did not change at all, so at least at the ends, the seals are good. 1500 miles on them.

I am also a new owner of another working CDI, as I picked one up and changed it after putting it all back together. Same as before, no difference. I am just about to look for those screens on the bowls, to see if I have a restriction. I pulled the fuel line going into the tank, and then pulled my filter out to change since I'm in this far now. Just a rehash, these are the items I've changed. Fuel Pump and lines, Stator, Coils, CDI. Oh what fun it is to ride.....
 

Attachments

  • PTO Piston.jpg
    PTO Piston.jpg
    159.7 KB · Views: 8
  • Center Piston.jpg
    Center Piston.jpg
    218.8 KB · Views: 4
  • Mag Cylinder.jpg
    Mag Cylinder.jpg
    226.6 KB · Views: 7
  • Head-Viper-PeakPerformance.jpg
    Head-Viper-PeakPerformance.jpg
    180.9 KB · Views: 8
Last edited:
I had your symtom happen only once on my 02 Viper a couple seasons ago. I was last is a group in some twisties on a clear cold night, and my sled suddenly just stopped like you hit the kill switch. It started agin after about 5 minutes, and never did it again. I had done the harness and the fuel pump fixes by then, so I know it wasn't either of those.

keep us posted as it will be interesting to see what the issue turns out to be.....
 
Well, well, well... I am not going to get a head of myself here...BUT...I just went through and pulled of the floats to get to those screens that I have been advised to look into. I could not believe what I found. See for yourself:
I am hoping that this is the smoking gun I have ben hoping for. The screen on the left is one that I cleaned, and you can actually determine that it was a screen. When I first pulled them out of the carb, the gunk that was covering them was a green/brown almost algae looking covering, w/ bits of dirt and whatnot. If you let it dry, it hardens into a white looking mass.
 

Attachments

  • fuel screens.jpg
    fuel screens.jpg
    140.7 KB · Views: 34
  • fuel screens 2.jpg
    fuel screens 2.jpg
    131.1 KB · Views: 27
  • fuel screens 3.jpg
    fuel screens 3.jpg
    167.8 KB · Views: 23
  • fuel screens 4.jpg
    fuel screens 4.jpg
    172 KB · Views: 34
  • fuel screens 5.jpg
    fuel screens 5.jpg
    177.8 KB · Views: 23


Back
Top