Anybody used a Built-in fuel pump ?

[ialonso]

So after 3 years of no boating after having children, I'm getting the boat back in shape. Engine has been rebuilt (low compression on one, and oil seepage on both made us mosquito sprayers quite a few times)

I have been unable to get parts to rebuild the OEM fuel pump, but I do have the Mikuni Built-in Fuel Pump that goes attached to the back of the carb in Jet Skis that share our carb and engine.

I'm unsure it will work. as I suspect there had to be a reason for the original designers of the boat to use the external fuel pump (Which is more complex and expensive install, requires several additional parts to the boat...it would have been cheaper to use the built in one, so I suspect if they did not use it, it's because it didn't work)

I'm hoping someone tells me I'm wrong and that you know this set up to work because you know of it working, or saw somebody's work. I'll take your thoughts too if you fell like sharing!

Thanks !!

 

[Dr Honda]

Your description is a little confusing. Did you swap the carbs to an internal pump carb? Or... are you asking if you can?

Regardless... Yes... an internal pump carb can be made to work without an issue.

As far as "Why did the engineers do it?"... who knows why they changed things. Probably just to keep them selves in a job. Over the years, they changed the carbs.

 

[ialonso]

Thanks for your feedback.

Sorry for the confusion. The carbs currently on the boat are driven by the oiginal external fuel pump.

I have new carbs with attached fuel pump in a box. The dealer I buy these from doesn't stock them without it, so, in the past, I would just take the pump off. (Third set I've bought over time)

I examined the pump, and it looks so small.... I guess I have to think of it pulsing 1500-7000 times per minute to visualize some flow. The OEM external pump doesn't look huge either.

Anything you can tell me that will boost my confidence in using the external pump ?

Thanks again !

 

[timmafod]

I just replaced both of my external fuel pumps in my '98 challenger 1800, because, at $80 new each, they were easier to replace than finding the internal pumps and rigging those up. For laughs, over the winter I took my original external fuel pumps apart and found all sorts of junk in them even though they were "working fine". One was physically busted inside but the engine it pumped still ran fine when I put it away for the winter.

But I guess if you already have new carbs with the built in pumps (i.e. from the seadoo PWC's), then that should work fine. If it worked in the skis it should work in your boat. I don't see any technical or reliability reason why the boats need their external pump.