RCU Forums - View Single Post - When is a pump necessary and what are it's disadvantages?
Old 11-03-2009 | 11:47 AM
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psuguru
 
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From: ChelmsfordEssex, UNITED KINGDOM
Default RE: When is a pump necessary and what are it's disadvantages?


ORIGINAL: cappaj1

I just purchased a O.S. FS-120 III Surpass 4-Stroke w/Pump as it was suggested due to tank location.

When is a pump necessary, or is it just a case of 'better, but not required'?

What are the disadvantages of having a pump? I have to prime the pump before starting which makes it more difficult to start - that's one - are there others?

Is there any test prior to mounting an engine to see if I indeed actually need a pump?

I guess what I'm getting at is are pumps often used when people think they need them where they could get by without one?
I didn't think that priming was a disadvantage, because you have to do it anyway, usually by choking the engine.
The OS carbs are pressure regulating types, giving better throttle reponse. Perry pumps "regulate" at the pump although I don't think it's quite as good a system.
Other than that there's more expense, I can't think of any disadvantages at all.