Primer bulbs

Pappy

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What motors are on them?

Like I mentioned before, if it's a newer EFI Merc, they do not recommend that you use a primer. I believe Yamaha is the same.
The bigger Yamahas come WITH a primer bulb in the rigging box!!
 

moedelawn

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The bigger Yamahas come WITH a primer bulb in the rigging box!!
I have one on my f115 Yamaha and f25 never used it after the initial prime. I thought about removing it until I was heading in one evening and some guys had a f70 Yamaha that ran out of gas in the main tank which was on the front of the boat. They had a small gas can and added some gas but with no primer it wouldn't pick up the fuel and the battery was getting weak. I had to connect it to my line and prime it. They were good after that. Not a bad idea to keep one in the boat. I've had to disconnect to remove water that was in the tank.
 

MrGiggles

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The bigger Yamahas come WITH a primer bulb in the rigging box!!

I guess I can only speak for the Mercs then.

A primer is not recommended for my 2011 90hp, there is no needle valve in the VST, if you overfill it with the primer, it will trip the vent switch, alarm, and kill the low pressure pump.
 

eeshaw

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I installed a factory primer bulb the other day on my project. I couldn't mount it vertically in the area I have available so horizontal it is. The water seperator had a 3/8 fitting that had to be swapped out for a 5/16, other than that it was good to go. When I get ready to water test the engine I'll have to replace the water seperator canister with a new one.
 

LDUBS

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I installed a factory primer bulb the other day on my project. I couldn't mount it vertically in the area I have available so horizontal it is.

I was not aware that they should be used vertically until I read this thread. I may be misunderstanding, but I think what is meant is to hold it vertically when using it. Otherwise it can lay flat? Maybe someone can clarify?

Mine lays flat (horizontal) in the splash well. It is basically unused.
 

MrGiggles

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I was not aware that they should be used vertically until I read this thread. I may be misunderstanding, but I think what is meant is to hold it vertically when using it. Otherwise it can lay flat? Maybe someone can clarify?

Mine lays flat (horizontal) in the splash well. It is basically unused.

The check balls in them don't work that well when they're dry. So if you're priming up a dry system, it helps to hold it vertical. Gravity holds the balls in place.

Otherwise I don't think it makes any difference, and once they're full of fuel, they work in pretty much any orientation.
 

RaisedByWolves

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I was not aware that they should be used vertically until I read this thread. I may be misunderstanding, but I think what is meant is to hold it vertically when using it. Otherwise it can lay flat? Maybe someone can clarify?

Mine lays flat (horizontal) in the splash well. It is basically unused.
They "Should" be held vertically, but in my experience as long as its in good working order it will work in most orientations.
 

airshot

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The verticle instructions are for when your pumping them, once fuel is flowing it doesnt make any difference as long as the ball is in good working order. I have tried squeezing the ball in various positions and it works far better in a verticle position but once the fuel is flowing, I can lay it in any position and it works fine. Most instructions say " when squeezing the ball, hold in a verticle position" .....
 

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