|
| Gray Fireball 188 mechanical fuel pump |
| Author |
Message |
    
Mike Disbrow
New member
Username: spectrum
Post Number: 1
Registered: 08-2010
| | Posted on Tuesday, August 17, 2010 - 02:08 pm: | 
|
Just joined here because I am absolutely out of ideas, beyond frustrated.
'64 Lyman 25' Hardtop with a 327ci Fireball 188hp and 1:1 Velvet Drive. NOT running original Carter side draft carbs. Have a 2bbl Holley on it.
Many years ago the mechanical pump failed on my grandfather. He removed it, blocked off the opening and installed a new electric pump. He's now over 80, loves the boat and the two of us have spent countless days fishing from it since I was a little kid. I've taken over much of the upkeep responsibilities so that he and I can still enjoy time together in this boat.
Back to the point, the last two years, nothing but fuel delivery issues. We've burned through 5 electric pumps while rarely ever getting away from the dock. Each time I replaced one, I changed something, looking for the cause. Rewired, new fuel lines, filter, and placement of the pump. I've suspected that the model of pump was just junk, but couldn't ever be sure until this weekend.
The pump always seemed to lose its prime, randomly. When it did work, once out on the lake, when the RPM were run up to 1600-1800, the motor started to starve for fuel. Idled great, but would run out of gas after a while at times. Carb bowl would be empty, could see the fuel 6" down the line when I disconnected it from the carb, but pump would barely move fuel when trying to pump into a bucket.
I managed to scrounge up parts for the mechanical pump and got one working. Installed it, removed the electric, and she runs like a champ. However, I have little experience with this mech. pump. There appears to be a small, maybe 1mm hole, in the top half of the pump housing, that faces toward the exhaust manifold (pump located on port side of motor). At higher RPM it seems to spray/mist either oil or gas from this hole with each stroke of the pump. I'm hoping it's oil and I'm not getting gas above the diaphragm. The gasket leaked a little oil when I installed the pump, so I cut a new one, reinstalled and cleaned up the little bit of oil. Since I had gas and oil on my hands, when I wiped up what was coming from that little hole, I couldn't tell by smell exactly. I'll be finding out for sure this evening.
What is this little hole for, is this a problem, etc. Any input?
Also, anyone have any recommendations on electric fuel pumps for this setup? I refuse to buy the same pump again. I've been looking at the Holley marine Red pump, and considering the higher pressure blue pump and installing a regulator near the carb. I'd love to be able to hang an electric pump off the front of the motor rather than back underneath the starboard rear bench seat, but given that they recommend pushing fuel versus pulling fuel with an electric pump and heat from the motor... I'm not trying to kill $150 fuel pumps.
Any help would be great. I'd really appreciate it. The fact that the motor runs with the mechanical pump tells me not to buy the same little inline Carter pump that's been dying ever again. But I'm still not pleased because I don't know what's going on with that little hole in the mechanical, and constant wondering how long it's going to last, and if gas is getting into the crankcase.
Sorry for the long post, but I really do appreciate anything y'all can tell me. |
kim hartshorn
New member
Username: kimhartshorn
Post Number: 1
Registered: 08-2010
| | Posted on Tuesday, August 17, 2010 - 04:01 pm: |
|
Maybe you alread checked this but does it run better with the gas cap off? Could it be a partial vacuum in the tank situation? Maybe somebody plugged the vent so as not to dump gas in the lake on filling. |
Mike D.
New member
Username: spectrum
Post Number: 2
Registered: 08-2010
| | Posted on Tuesday, August 17, 2010 - 04:32 pm: |
|
The vent is clear. I've disconnected it and checked that. I've tried w/o the gas cap on, partially screwed down, fully closed as well.
The tank is relatively new. My grandfather had a new one made within the last 10 years.
I even put in a primer bulb I had sitting around new in the package. Just wanted to use it to join the fuel line together temporarily to bypass the water separator and make sure there wasn't a problem there. When the motor started to starve, a squeeze of the bulb would keep it running.
This is the electric pump he's been buying. http://www.napaonline.com/Search/Detail.aspx?R=NFPP74029_0202258085#
After seeing the specs on it, I wouldn't be surprised if it can't keep up. I won't buy the same again (the only pump his local NAPA carries). I tried the mechanical to confirm that the problem is indeed that electric pump.
I'm still hesitant to tell my grandparents they can take the boat out w/o worrying, because I'm not sure what's going on with that little vent hole spitting. I'd feel better with a reliable electric pump, or at least knowing why the mech. pump is doing that. |
lynn ault
New member
Username: luckylyman
Post Number: 1
Registered: 07-2012
| | Posted on Thursday, July 05, 2012 - 05:46 pm: |
|
this is a response to Mike D,'s message of August 2010.
I've been told the hole in the pump body is a vent for gas vapors, and to release the vacuum, and it should have a small line running up to the air filter (spark arrestor).
I've also been told that electric pumps are better pushers than pullers, and therefore should be located close to the tank, not close to the engine. |
david garvin
New member
Username: old_school
Post Number: 2
Registered: 05-2012
| | Posted on Friday, July 20, 2012 - 05:44 pm: |
|
in the event of a diafraghm rupture hole is there to allow gas to vent rather than filling up the crankase and dilluting the oil,and Lynn is correct there should be a hose leading to the intake side of carb from the hole incase it happens. |
|
|
|
|
