fuel pump theory

[addicted]

It is apparent that the stock single outlet pump is lacking in the flow department. To combat this most either add a supplimental pump or replace the stock pump with a 3 outlet pump. I have a 94 sl750, and a 96 raider 1100. The raider has a single outlet mikuni pentagon pump. Both ski's in stock form use a fuel rail setup for both supply and return. I have never heard of, or experienced a problem with the yamaha setup.

My question is this. If the stock polaris pump was replaced with a single outlet pentagon pump, would the fuel rail setup provide adequate supply, or is there another inherent problem with the fuel rail setup? I noticed that the raider has the supply and return on opposite ends of the carb rack where the polaris has them both on the same PTO end. Does this make any difference?

Any feedback is appreciated.

[surveyguy]

Re: fuel pump theory

I don't think there is any problem. There are restrictors in the rail to keep plenty of pressure at the carbs, but I have never heard of a 'problem' with the fuel rail system being a culprit.

[addicted]

Re: fuel pump theory

Restrictors as in more than 1?

[Wet Wolf]

Re: fuel pump theory

each carb has its own restrictor built in, there should also be a restrictor inside the return line to the tank located about a half inch from the carb, there is should be a zip tie holding it in place.

[addicted]

Re: fuel pump theory

I knew about the one in the return line, but not about the ones in the carbs themselves. Are they removable, or simply molded into the nipples on the back of the carbs?

[dblank02]

Re: fuel pump theory

The restrictors ar molded into the carbs return.

[surveyguy]

Re: fuel pump theory

yup, molded in, meaning the passage in the aluminum part, between the rubber hoses, has a brass insert with a small hole in it, like 1/16 " or something.