1977 merc 188hp fuel issue

[Ted K]

This boat has been in storage 7 years. Have done all my preliminaries and went to start it but don't seem to get fuel in carb. Do I need to prime? Fuel/water separator? pump? Maybe battery went down before I cranked it enough. Any ideas? Thanks!

 

[duped]

Re: 1977 merc 188hp fuel issue

My 73 888 had the same issue. Nature of the beast with a mechcanical fuel pump, especially if the tank is far away, boats been sitting, etc...The old fords like ours seem particularly worse for some reason.

I fixed mine by adding a small electric booster pump near the tank. I run it on a push button switch. Once I see fuel at my clear filter after the water separator, I shut it off.

http://www.amazon.com/Mr-Gasket-12S-Micro-Electric/dp/B000BWCERY

Otherwise just get her going on starting fluid thru the carb, it wont take long then for the mechanical to start pumping.

The other possibility is that your mechanical pump is corroded beyond use from stale gas. Its another cheap fix though, I believe under 20 bucks...

 

[Bondo]

Re: 1977 merc 188hp fuel issue

Ayuh,... It could be the Tank or the lines inbetween too...

 

[Ted K]

Re: 1977 merc 188hp fuel issue

So, I don't need to prime or pre fill the fuel water separator? Maybe I should remove line from separator and blow air to dislodge any clogs between there and tank. (thinking out loud here)

 

[haulnazz15]

Re: 1977 merc 188hp fuel issue

No reason to remove any lines unless you want to verify fuel pressure. I also haven't noticed the Ford fuel pump taking any longer than a Chevy. Have you looked at the fuel pump glass container (or fuel vent line) to make sure the fuel pump diaphram hasn't ruptured?

 

[Ted K]

Re: 1977 merc 188hp fuel issue

Update: No fuel at carb, removed and replaced fuel/water filter separator, checked sight glass on pump (dry). Next??

 

[Ted K]

Re: 1977 merc 188hp fuel issue

What if float is stuck? Would it then not allow air to bleed out and fuel to reach carb? I have been looking for a delivery problem but it might be pumping just no where to go. Maybe?

 

[duped]

Re: 1977 merc 188hp fuel issue

Have you tried filling the float bowl with fuel, or running on starting fluid to allow it time to pump fuel? There is a lot of apparatus for the gas to be pumped through before it reaches the carb. Its been sitting for 7 years, the lines are surely dry, if not needing replacement anyways. When I saved mine from the grave it took maybe 10 seconds of running on spray before gas reached the carb.

Either way a stuck float will not typically cause an engine to get no fuel. It will do quite the opposite actually

But for when you do get it pumping, if it has the holley carb, you can check float level by removing the sight plug at the side of the bowl. Gas should just start to trickle out with engine running. Clockwise lowers the float level and counter clockwise will raise the level on the screw at the top of the float bowl.

Anyways try what I said first. For all you know right now the engine doesnt run anyways. I'd be on the starting fluid in a heartbeat. If fuel still doesnt pump, replace all the lines, and the pump. Its old and could use it anyway. Cheap insurance. End of story.

 

[Ted K]

Re: 1977 merc 188hp fuel issue

Thanks, I will try that tomorrow. Been holding off using starting fluid but, what the heck. What I do know is that it ran and was professionally winterized before storage. (the owner died shortly afterward) I will update tomorrow.
BTW: This engine has a Rochester carb!

 

[Ted K]

Re: 1977 merc 188hp fuel issue

Update: Found no fuel @ Carb fitting, removed line from fuel/water separator to tank @ separator. Removed Fuel cap and applied air to fuel line (30psi) no bubbles, increased all the way to 100 psi and got nothing. I am going to pursue this as a clogged fuel probe unless anyone has a better idea. I would have continued to the probe already but ran out of time.

 

[supercab78]

Re: 1977 merc 188hp fuel issue

If your trying to push air into the fuel tank, you should know there may be a anti bleed back valve (check valve) on top of the tank. That would prevent you from doing that. If the needle & set are stuck shut fuel may not be able to get in the carb. Depends on the type, more then one float or not. What type of carb is it. I've had Holley's stick shut on me before after sitting a long time. Say 6 months.

 

[Ted K]

Re: 1977 merc 188hp fuel issue

Rochester 2bbl. carb. The top of tank looks to me to just have a barb going into an elbow which is threaded on a nipple to tank. I have diconected the line @ carb to no avail.
Edit: My point here and the reason for previous post is that I do not see an anti siphon valve but was aware there may be one. Could this be a part that would be hidden, (IE, in the tank) ?

 

[supercab78]

Re: 1977 merc 188hp fuel issue

The one on my old 1975 searay didn't look like one(anti siphon) until I took it off and saw the inside. From the outside all it looked like was a brass fitting about 1 inch long once it was off. I found mine while looking for a fuel restriction. The O ring in it went bad. Have you pulled the line from the tank and carb to check it for blockage. When starting my old searay for the first in the season or after a long period of no use, it would take a long-long time to get fuel in the carb. My cheap fix was to install a outboard fuel primer bulb. Do to the tank to engine distance- 9 feet- it would sometimes take about 40-50 squeezes to get fuel in the carb. You could use basting tube to put some gas in the vent hole on top the carb. Maybe about 2 oz. -------BE CAREFUL OFTHE FUMES-------- just to see if it will start. The good news would be the engine should be primed of oil now.

 

[HT32BSX115]

Re: 1977 merc 188hp fuel issue

Howdy,


You might have an anti-siphon valve.

I'm not sure they were required in 1977 though....

I would probably look carefully at the fuel pump too. If it's that old and hasn't been run in all those years, you may have a dry (possibly ready to crack) diaphragm and/or stuck check-valves inside.

If the (mechanical) fuel pump is suspect in that manner, and it's been all these years, you should probably replace it.

If you run it you may find that it's filling the pan with gas (and gas in the sight tube to the carb)

Regards,


Rick

 

[Ted K]

Re: 1977 merc 188hp fuel issue

Well, just goes to show that looks are deceiving! Have not had the chance to go further but by Rick's photo, I have to assume I DO have an anti siphon in there. I hope to check that next. Thanks.

 

[ziggy]

Re: 1977 merc 188hp fuel issue

have ya tried running it on a remote fuel tank?
if it gets fuel off the remote fuel tank, the problem would lie in ft. of the fuel pump. if it don't run, the problem would be either the fuel pump or after. heading off towards the carb.

 

[Ted K]

Re: 1977 merc 188hp fuel issue

It's Alive! Low and behold I had a clogged anti siphon valve. Removed, cleaned, replaced and removed line from carb. and hooked hose to empty container. Cranked engine and pumped gas! Hooked everything back up and first turn of the key she fired up! Good oil pressure, alternator working but don't think it's cooling properly. Next step, lower unit I guess. Thanks every one! Wonder if I can do an impeller change myself?

 

[HT32BSX115]

Re: 1977 merc 188hp fuel issue

Wonder if I can do an impeller change myself?

Yeah. It's pretty easy. look around on the net,
there are videos on Youtube and I think "Mercstuff" and/or Marineengine.com has step-by-step's with pic's if you don't have a service manual.....

 

[Ted K]

Re: 1977 merc 188hp fuel issue

Thanks Rick. I have the manual from here (before they were removed) but the extra material you suggested will be great. Your photo saved me a lot of wasted time yesterday, again, thanks. I would have never thought the anti siphon was that small. I suppose I better go get some gaskets before dropping the gear housing? I believe there is a replacement impeller in my bag 'o parts already. Should I just get the whole water pump kit maybe?

 

[HT32BSX115]

Re: 1977 merc 188hp fuel issue

My previous boat (1966 MarkTwain 150 Mercruiser)

needed a raw pump. I replaced EVERYTHING that was raw water pump. impeller, housing, everything.

It's probably a good idea make sure all the parts are new.