TOPIC: A "primer" on fuel line primer bulbs....OB's

Happened again today, another here. New bulb in and don't work to pump up firm? Well "duh", when I saw it. Read on...from another found the net...

Last season I overhauled the fuel lines on my 1987 Whaler. In the process I replaced the primer bulbs. I really have not been happy since then, until I discovered a secret that I am about to reveal to you.But first, some history:
The existing primer bulbs were OEM Yamaha bulbs, and they really were working fine, even if 14-years old. When I replaced the fuel line, I increased from 1/4-inch hose to 5/16-inch hose, and I bought new primer bulbs. I got the TEMPO brand primer bulbs off the shelf at WEST Marine.
(By the way, I noticed a vast difference in the suppleness of the rubber in the dozen or so TEMPO brand bulbs hanging on the shelf. Some were very firm, some were very soft.)
When I put everything back together, I made the mistake of not pre-filling the fuel filter bowl of the water-separating filter with fuel. I had to squeeze a million times to prime the system. Finally I got gas through the hose, but the primer bulb behavior was qwerky. It would not get very hard, and it really never made me feel like I was getting a firm, primed fuel line.
The engines ran and everything worked well, so I just ignored it. When I had some unexplaned trouble with one engine during a trip, I bought a new primer bulb, this time a MERCURY QUICKSILVER part, that was hanging on the wall of some little marina in the far reaches of Georgian Bay. This did not seem to work any better, even though it cost me about three times what it would have in the States. To top it off, this bulb was stiff as hell, probably from sitting in that bubble pack for ten years on the wall of the marina before someone as crazy as me paid the asking price.
I complained to my Mercury mechanic, and he said try the newest Mercury primer bulbs. These are much improved, he claimed. So I bought another one and tried it.
The results were the same. The primer never got very firm, but the engine ran fine.
This spring, I was over at the shop checking on the boat (which is having some work done on the engine lower units) and complained to the mechanic about those primer bulbs. Then he showed me the problem.



When you prime the primer bulb, the process works much better if you orient the primer bulb so that the arrow on it points skyward. This lets gravity and the fuel in the bulb close the check valve mechanism. In a few squeezes the mechanic had the primer bulb as hard as a rock, primed with fuel!

Of course, once the magician reveals the trick, it makes perfect sense.
When I re-rigged the fuel lines, I had inadvertently changed the location of the primer bulbs so that the orientation of the arrow in the bulbs pointed downward. This tended to make the check valve not work as well, and the result was I could seldom (if ever) squeeze them to a nice firm primed state.
Those days are now over. I just have to move the primer bulbs to a section of the fuel line where they will point upward.

Am I the last boater on earth to discover this trick? I've never seen it mentioned anywhere.

(Me now..YEP, as the rear flapper valve will NOT close! )

After owning boats all my life, I just realized recently that this works. Always thought the arrow just meant "this way to motor". But tilting the bulb up like that makes the priming go much faster.

Ok 1st a few facts then my opinion (for what it is worth)

Fact 1 (or maybe this is an opinion?) Tempo products were typically above average quality for many years.

Fact 2 Tempo was owned by an old guy that wanted to dictate terms to his customers and they balked, so he shut the company down about 5 years ago. (This was from my supplier, Bell Industries).

Fact 3 Moeller bought Tempo a few years ago and brought back the name. Moeller is in my opinion low quality and the new Tempo is also.

Fact 4 is that ethanol deteriorates pre 2011 bulbs rapidly. Some products like the Moeller & Mercury bulbs just simply split open. Attwood become rock hard.

I use only OMC/BRP bulbs and fuel line.

Now regarding my opinion on the arrow pointing up; I too discovered the same phenomenon. I believe that in the old days (like 60s, 70s and such) that there was a check valve on both the inlet and outlet of the bulb. those old bulbs didn't seem to care how they were orientated so long as the arrow pointed to the engine. Newer bulbs only have the one check valve and need gravity to help them function.

my 62 merc 700 has the the same problem. i have to squeeze that bulb forever. i bought a 9 gallon plastic tank (i think tempo) from west marine. i can't remember if i had the same problem with the original metal mercury tank. so i have to hold the bulb skyward when i prime? what if the arrow is pointing towards the tank? or is that improbable? ron

I agree 100%!


jimandros wrote:

Ok 1st a few facts then my opinion (for what it is worth)

Fact 1 (or maybe this is an opinion?) Tempo products were typically above average quality for many years.

Fact 2 Tempo was owned by an old guy that wanted to dictate terms to his customers and they balked, so he shut the company down about 5 years ago. (This was from my supplier, Bell Industries).

Fact 3 Moeller bought Tempo a few years ago and brought back the name. Moeller is in my opinion low quality and the new Tempo is also.

Fact 4 is that ethanol deteriorates pre 2011 bulbs rapidly. Some products like the Moeller & Mercury bulbs just simply split open. Attwood become rock hard.

I use only OMC/BRP bulbs and fuel line.

Now regarding my opinion on the arrow pointing up; I too discovered the same phenomenon. I believe that in the old days (like 60s, 70s and such) that there was a check valve on both the inlet and outlet of the bulb. those old bulbs didn't seem to care how they were orientated so long as the arrow pointed to the engine. Newer bulbs only have the one check valve and need gravity to help them function.

vuyosevich wrote:

my 62 merc 700 has the the same problem. i have to squeeze that bulb forever. i bought a 9 gallon plastic tank (i think tempo) from west marine. i can't remember if i had the same problem with the original metal mercury tank. so i have to hold the bulb skyward when i prime? what if the arrow is pointing towards the tank? or is that improbable? ron

I have the same "problem" with my Merc. 12 gallon tank in the middle rear my Flat Bottom. Yes arrow must point the direction of flow, like to the motor. My bulb (Wally World, forgot make)is flat on the tank. I can pump it that way, but it will not flood the carbs to start. Just point it up and no problem.

A little more searching...

Orientation

It is also advantageous if the primer bulb can be position in such a way that during priming it can be oriented vertically, with the direction arrow pointing skywards. This will allow gravity and the weight of the fuel inside the primer bulb to help with the operation of the one-way valves. If the primer bulb is oriented with the flow arrow pointing downward, gravity and the weight of the fuel in the line above the inlet check valve may spoil its operation, and the primer will not work properly.

This subtle but important point—orienting the primer bulb skyward—is often overlooked in many installation, but it really helps the primer bulb to do its job. This trick was shown to me by an experienced Mercury outboard mechanic, after I complained that the new primer bulbs he had installed did not work well. The difference in results is amazing, and just by changing the orientation of the primer to vertical, its operation is much improved. In just a few squeezes it should be possible to fill the bulb with fuel.

gotcha...i'm able to hold the bulb vertically. will try next time out. thanks, ron

vuyosevich wrote:

gotcha...i'm able to hold the bulb vertically. will try next time out. thanks, ron

Glad to help as what worked effortlessly with no thinking the old days when at least me anyway.."learning" has been so "improved" now ya gotta learn all over again. Think it this way as I remember when everything came with twist off caps. NOW? "Everything been child proofed" Don't get me started on "stupid" fixing what worked, with "new and improved"..(if even can get the damn package open first!).

Life is fun, laugh and enjoy it. Be something new to figure out tomorrow anyway!

vuyosevich wrote:

gotcha...i'm able to hold the bulb vertically. will try next time out. thanks, ron

You should have a few weeks left to give it a try. Actually, you should be able to just try it in your driveway after the boat has sat a few days.

We had a rain snow mix last night, some areas had a white coating this morning but not at my house.

My original Honda bulb in the 2007 era deteriorated badly. I cut it open and it had black residue and cracks inside. I did notice the new bulb worked better. I shortened the supply so there was no unnecessary loops in the line and the bulb was hanging down about 10 inches from the motor so it was in the up mode. Nice to know.