have to pump ball after engine sits for more than 15 minutes

[lbhsbz]

Boat is relatively new to me....just got back from my second weekend out with it....87 merc blackmax 200hp, 2.4L

I put a new ball in line because the one that came with the boat was cracked, and I replaced the 2 gaskets, diaphragm, and a couple o-rings in the stock fuel pump, as well as cleaning the screen. Oil injection has been removed, and I put a vacuum cap over the oil inlet on the fuel pump. Fuel lines have all been replaced....first weekend out I found a pinhole that was causing pump to suck air and not prime. I originally just cut the bad spot out and shortened the hose a bit, but it would run out of gas over 5000RPMs so I replaced the lines from the quick connect to the pump, and from the pump to the top carb and used hose clamps instead of zip ties. Turns 6300-6400 now no problem.

If we pull up at a beach or something, or even just shut if off to float for a bit, It'll start and run off of the fuel in the bowls, then die and will not restart until I pump the ball. After having done this a few times, I started pumping the ball before restarting and it works fine like that, but is annoying. I can usually get 2 or 3 pumps before the ball gets hard.

WTF is going on here??....bad check valve assembly in the pump? The ball seems to work so I can't see a bad check valve in the ball being the issue. Also, makes no difference whether I tilt the engine up or not, problem exists regardless.

[laglass69]

Check to see if there is a anti-syphon valve in your tank, if so remove it.

[XstreamVking]

The primer bulb should point up (outlet up) Theres a check valve in the bulb that seals best in the verticle position..... Might be just that easy....

[lbhsbz]

The primer bulb should point up (outlet up) Theres a check valve in the bulb that seals best in the verticle position..... Might be just that easy....

Hm...mine's laying on the floor in a pile of other crap. I'll add some zip ties and try it again.

Thanks.

[sjcolwell2]

mine usually takes a few weeks to do that and its not vertical

[laglass69]

mine usually takes a few weeks to do that and its not vertical

:iagree: Every boat I've ever had that a primer ball in it, I've never worried about what position it was in. Not saying it couldnt be the problem but If it only takes 15 mins to lose prime, I think something else is going on. Anti-syphon valve, air leak or could be faulty connections on the ends of the hose.

[perfmarine1]

:iagree:
The primer bulb should point up (outlet up) Theres a check valve in the bulb that seals best in the verticle position..... Might be just that easy....


The anti syphon valve would prevent gas from running back in to tank. Although for hi perf use we always remove them.

[XstreamVking]

Short discussion on primer bulb install from the whaler site...To explain the reasoning of vertical install....


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.

[flabum1017]

did you replace the check vlves in the fuel pump too?

[lbhsbz]

Ok, the plot thickens.....put the boat in the water friday night, pumped the ball till hard, fired it up, idled out about 100 feet and got it up on plane. ran it around 3000rpms for a mile or two, then got on it....started loosing power at about 5700rpms like it was running outta gas, so I lifted, switched tanks, pumped the ball a few more times, and tried it again...same thing happened. Installed a new Attwood ball/hose assembly (only thing I could find in town) and it now runs fine to 6200 or so. Good enough.

Another thing I noticed, as well as losing prime when sitting, is that it will not pump fuel at low RPMs. If I idle for more than about 30 of 40 seconds while motoring out of coves or such, it will die as soon as I try to get on plane. Runs fine over 3000 rpms.

I know the pump runs off of crankcase pulses....and I'm assuming from the center cylinder on the port bank. Last compression test I did showed 70 psi on the port bank, while over 100 on the starboard bank....Yeah, I know it's hurt, but it still runs in the high 70s/low 80s at 6200 w/ a 24 pitch chopper. The cylinders are all scarred up on that bank, so the block isn't really worth fixing I don't think. I'll run it till it spits a rod, unless this stupid fueling issue is a result of the hurt cylinders not creating enough of a pulse to run the fuel pump.

[perfmarine1]

I would not keep running it.Right now it is rebuildable,if you keep running and seize a piston,chances are you will break a rod and break the block,then you cant rebuild it. After you rebuild it throw that pump in the trash and go electric.

[lbhsbz]

Isn't it about $200/hole to fix the block? Is it worth spending $600+ on a 2.4L? I've got a good XR4 block to build after I blow this one up, and a complete 83 200hp drop on to use in the mean time....just kinda wanted to see how long this would live with the abuse I dish out to it. So far, I'm impressed.

[perfmarine1]

Right now its only $35 a hole. If rod goes through block it's a anchor! You aint fixing it with a sleave!

[racer]

I agree fix it while you can. You might also want to check your tach as 6200 with a 24 is 75 before slip.

[lbhsbz]

Well, now it'll need at least 3 holes bored and replated or sleeved. $35 each hole? where do I send it?

[perfmarine1]

Well, now it'll need at least 3 holes bored and replated or sleeved. $35 each hole? where do I send it?

Do you know that it is a coated block? You should if you have seen the scars,that would be my mistake I was thinking bore,sleeves are indeed 200+ a hole. I have a 150 merc from the era 86 and it is steel.

[surfjeepzx]

I would ditch the Attwood bulb and cough up the change for a Merc/Quicksilver model. The difference is so obvious as night and day.

[lbhsbz]

Do you know that it is a coated block? You should if you have seen the scars,that would be my mistake I was thinking bore,sleeves are indeed 200+ a hole. I have a 150 merc from the era 86 and it is steel.

Right. Mine are chrome bores. Not worth spending the money on it...being a 2.4 fishing mota and all...

[service860]

sorry but low compression and wont warm restart and idle lol.

[lbhsbz]

It starts fine and idles till the bowls run dry, then the ball is soft for a few pumps. Aside from the compression problem, I've got a fuel issue.

[laglass69]

If the ball keeps going soft, its sucking air somewhere in the fuel system.

[lbhsbz]

Took the tanks out, cleaned 'em up (didn't find anything in 'em) and got rid of the anti-siphon valves. Idles/starts awesome now....didn't have the pump the ball at all over the weekend, except when I launched it.