bucky
New member
I went ahead and raised my fuel pump and put silicon in the deaphram hole. Any success with this method? Seems like a good theory. Frozer up once last year. Why would tthey put a hole in the bottom like that anyway? Seems foolish, Thanks for the feedback. 
I with you but all I know is it works....
Raised it up and took silicone out
Some previous posts stated that by plugging the hole, you could get a lean condition.(maybe) I had mine sitting on the bulkhead and sealed.
Went ahead and took out silicone and raised it. Works perfect so far. Only thing I could find is that you would plug the hole so water would not get in and freeze. Since it is raised, no water can get in anyway, so I remoeved the hole to be on safe side.
Some previous posts stated that by plugging the hole, you could get a lean condition.(maybe) I had mine sitting on the bulkhead and sealed.
Went ahead and took out silicone and raised it. Works perfect so far. Only thing I could find is that you would plug the hole so water would not get in and freeze. Since it is raised, no water can get in anyway, so I remoeved the hole to be on safe side.
I never have plugged them I have always just took the pump off and added a nut to the studs then put the pump on and a nut to hold it in place and have never had one ice up....
bucky
New member
I plugged mine. Hope it works. Started it today and it sounded fine.
plugging them works ...just always in the back of my head I am thinking why have the vent...is there a reason...hmmm so I shim them instead...LOL
B2SO
New member
- Joined
- Aug 18, 2003
- Messages
- 422
- Age
- 52
Pump
Same Thing here.. I had mine pluged with silicone for two seasons , I never had a problem , But i also bought into the lean Theroy with it pluged . I think the vent allows the carb to get more fuel if needed (somehow
).. I really dont know for sure ,So i unplugged it put a few washers under it ..It also Works fine ,I have run bender tripples with the vent pluged and unpluged...With no problems ...But i agree with Mr. sled.. Why put it there if its not needed???
Same Thing here.. I had mine pluged with silicone for two seasons , I never had a problem , But i also bought into the lean Theroy with it pluged . I think the vent allows the carb to get more fuel if needed (somehow
).. I really dont know for sure ,So i unplugged it put a few washers under it ..It also Works fine ,I have run bender tripples with the vent pluged and unpluged...With no problems ...But i agree with Mr. sled.. Why put it there if its not needed???sx600
New member
- Joined
- Aug 10, 2004
- Messages
- 107
I am planning on using silicone, just got the sled. The Yamaha TSB says to silicone it and that the fuel pump will work just fine with the vent hole closed...
The vent is there to let air pressure in and out as the diaphram strokes back and forth. When the hole is plugged there is a chance that diaphram movement could be dampened (because pressure/vacuum is not allowed to escape) and reduce maximum fuel flow at high rpms. On a stock Viper this shouldn't be much of an issue, since the fuel demand of stocker wouldn't push the max fuel flow limits of the pump.
A piped Viper with large main jets turning 9000 rpm is going to push the limits of a fuel pump. On a long WOT pull, you need all the fuel full posible to make sure the fuel in the carbs stays at the proper level. If there is not enough max pump flow, on that long WOT pull fuel levels will slowly start to drop untill you let off the throttle and the pump recovers or SQUEAK.
I raised the pump off the tunnel and did not plug the hole. No freezing problems in 3 years. My Viper is piped so I figure why chance it.
A piped Viper with large main jets turning 9000 rpm is going to push the limits of a fuel pump. On a long WOT pull, you need all the fuel full posible to make sure the fuel in the carbs stays at the proper level. If there is not enough max pump flow, on that long WOT pull fuel levels will slowly start to drop untill you let off the throttle and the pump recovers or SQUEAK.
I raised the pump off the tunnel and did not plug the hole. No freezing problems in 3 years. My Viper is piped so I figure why chance it.