Robby321
10-03-2014, 08:44 PM
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! )
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! )