Gas line size

[iggyw1]

I have a 1991 Nissan 70 H.P. motor. It has a 5/16" I.D. gas line coming from my water seperator to the motor. I have to replace the primer bulb. I have three brand new primer bulbs in my garage, but they are for a 1/4" gas line. I was just wondering if I can get a reduced splicer and put a 1/4" piece of house (which I have a brand new 1/4 section of hose) just on each side of the primer bulb, about one inch long at each end, and leave the remainder of the gas line at the 5/16" size, if this would effect the performance of my motor? Will it still get enough fuel to run at WOT if I reduce the gas line by the 1/16" just at both sides of the primer bulb? Thanks.

 

[iggyw1]

Problem solved. Did not get any replies, so I figured nobody knew the answer. I got it running good the way I did it.

 

[pvanv]

It should work, but that's a lot of fittings and stuff. I would just use a 5/16 bulb.

 

[Scott Danforth]

the additional restriction in the line may not effect performance initially, however it will shorten the life of the fuel pump. remember, going from .31" to .25" is a reduction in area of 33% (0.050 sq inches vs 0.075 sq inches) since the area is now 0.66 that it was, and the restriction goes up exponentially with the reduction of area, that will put you over the recommended inlet restriction.

I would have gone to a 5/16" primer bulb myself

 

[iggyw1]

Just to let you guys know, I did end up getting the right sized ball (5/16") for my motor. Thanks!