slow starting, have to pump gas to carb. after sitting for a week

S

Searay 24

New Member
Jan 21, 2013
3
tn
Boat Info
1994 searay 24' select cuddy cabin
Engines
454 mercruiser w/ bravo 1 drive
I have a 1994 Searay 24' cuddy cabin, 454 merc w/ bravo 1 drive. After sitting for about a week have to keep pumping handle to get gas back up to carb, then runs fine, also starts easy and runs fine if used on daily basis. My best guess is the gas is draining back into the tank over time. Is there a part that is not working or is this normal with the fuel pump connected to the raw water pump drive? Help needed, Thanks
 
Very common compliant with that generation of carb motors. Depending on the carb, the gas basically drains into the engine not back to the tank. If it is the original carb (Quadrajet, Weber, Carter etc.) that's the issue. It does't help that the fuel pump is also mechanical. The fix if you are so inclined is to replace the carb and/or put an electric marine fuel pump in to fix the problem. A marine Holley carb has two fuel bowls and solves the draining problem (evaporation will still be a problem if it sits for a few weeks). The combination of a Holley carb and electric fuel pump give you the closest thing to turn key starting you can get.

-John
 
Before you start pumping the throttle, try doing a couple few second turn overs w/o pumping the throttle, this will get the gas up to the carb, after that a couple pumps is all you should need.
 
PlayDate said:
Very common compliant with that generation of carb motors. Depending on the carb, the gas basically drains into the engine not back to the tank. If it is the original carb (Quadrajet, Weber, Carter etc.) that's the issue. It does't help that the fuel pump is also mechanical. The fix if you are so inclined is to replace the carb and/or put an electric marine fuel pump in to fix the problem. A marine Holley carb has two fuel bowls and solves the draining problem (evaporation will still be a problem if it sits for a few weeks). The combination of a Holley carb and electric fuel pump give you the closest thing to turn key starting you can get.

-John
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Thank you for the detailed fix, was hoping would be a less expensive way to correct, at least I know how now. Thank you Mike
 
Thanks for the info, will try, sounds like an expensive fix to correct. Thanks Mike
 
My experience is identical to yours and my solution is identical to the one offered by susanandlance. My engine turns right over if I do that and I don't consider it to be a big inconvenience.
 
Put some Marvel Mistrey oil in gas it lubes up accelator plunger the gas blend today destroys the rubber it works wonders and will start with no pumping.
 
Very common issue on Rochester carbs...well plugs leak and the fuel in the float bowl leaks into the engine. Pretty easy fix if you know a carb guy and can get a carb kit.


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Mine had, and when cold has the same issue. We rebuilt both qJets and when they get cold I still need to pump the throttles. I look at it this way, when I owned an old Ford truck and even when I drove an old Ford Firecat, you had to pump the throttle as you started the thing. A rebuild will help, but it won't stop the problem. It just is what it is. Take your time, start them up, let them warm up, and go enjoy your day on the water....
 
I had the same problem with ours if not run for a few days. Did a complete rebuild on the carbs and re-epoxied the main well plugs. They commonly shrink over time and begin to leak draining the fuel into the engine. Both engines fire right up now no matter how long they sit.

Here is one of many websites that go through problems and rebuilding quadrajets: http://www.crankshaftcoalition.com/wiki/How_to_rebuild_a_Rochester_Quadrajet_4MV_carburetor
link referencing the main well plugs: http://www.crankshaftcoalition.com/..._4MV_carburetor#Leaking_float_bowl_well_plugs

Good Luck with a fix! :thumbsup:
 
Lance is right on. I had a dock mate with a beautiful old Cruisers UltraVee with two Cruisader 454s w/1200 hours. The PO had told him to pump the throttle 10 times while cranking. What he really needed to do was crank for 10 seconds to get the mechanical fuel pump to fill the bowl, then pump the throttle once or twice - the first pump sets the choke for start and lets the accelerator pumps shoot a squirt of fuel in the carb throats. The second pump shoots another prime into the throats. Then crank and it starts right up. Once he did it that way, she always cranked perfectly and quickly.

Remember back to your older carbureted cars - you had to pump the gas once to set the choke and that also shot a prime of raw fuel into the manifold. Same thing here. If you run it every day there is fuel in the bowls and you don't need the 10 second crank to refill them.

One fuel injected cars (and 8.1's in boats), you just crank and they start...
 
This is just old school, an extra 30 seconds to start the engines when not being used omg. The bright side you will know if anyone used the boat if it fires right up.
 
Well I have same problem with my weber.I tanked it,rebuilt, and repainted,It did have a bent needle.I thought that and being dirty my problems were gone.Nope! I too have starting issues after a while not running.Plus after a long day on hook same problem.Runs great idles great.Bad start ups are getting old.I thought fuel pump would be next go.If that doesn't fix may try electric pump then try Holley.I have two buddies with same set up.They start up like fuel injection every time.
 
Common QJet issue. The good part is the engine is prelubed before it fires! I crank my 454 until I get 45psi oil pressure and stop. Pump twice to set the choke and crank her over and she fires right up, Mike.
 
northern said:
CV-23
How long do you crank the engine to get 45PSI
Click to expand...

About 15 seconds. My engine holds about 50 psi constant at 160 degrees at 3800rpms cruise. 40 psi after a hard run at idle and then back to 45psi at 1200rpms. 60psi at start-up. I use Delo 15w40. I only run the starter 15 seconds at a time and wait 10 -15 seconds to cool. Crank again and she fires. When warm it's an instant start, Mike.
 
Thanks for the thread. I only got our 330 with the twin 7.4 just before Christmas. I was having problems starting and trying a few different starting procedures. I think I will try cranking over before pumping. Awesome resource this forum :) Making a mechanically dummy a bit smarter
 
It took my dealer to teach me the way...... I ran one battery dead.....flooded the port side more than once, and felt like a complete idiot, but he taught me how and very well. As for the forum, I met the PO to my boat here and have learned more about boating and Sea Rays than I could ever wished.
 
CV-23 said:
About 15 seconds. My engine holds about 50 psi constant at 160 degrees at 3800rpms cruise. 40 psi after a hard run at idle and then back to 45psi at 1200rpms. 60psi at start-up. I use Delo 15w40. I only run the starter 15 seconds at a time and wait 10 -15 seconds to cool. Crank again and she fires. When warm it's an instant start, Mike.
Click to expand...

Hello all. I would like to resurrect this thread with one more question. Are you seeing issues with burning up the starters cranking them for that long? Some of the mechanics on my pier just cringe when they see me cold crank the engines for even more than one or two revolutions trying to get them to start. They also cringe when they see me pump the throttles, but I don't think they know this carb issue very well.

Also, are you giving it full range pumps of the throttle and back? Or just half way?

I just found this VERY helpful thread tonight as I am dealing with this exact issue. I'm in my first month of owing and living on our 1991 Sundancer and we are just now finally getting ready to start taking her out after repairing a number of things including new bilge pumps and blowers. NONE of them were working. Long story. Thanks in advance for any advice. Steve
 
With all due respect to the previous posters.....you need to address the problem not crank the engine. No engine needs to be cranked for 15 seconds before it starts. If that were the case, every manufacturer would require it......and no one does.

The problem is that the carb leaks down and the mechanical fuel pump has to refill it. Pushing the throttles up and down without fuel in the carb does nothing and frankly looks silly. You have two choices if you want to fix the problem: 1) Put a a marine grade Holley carb on it....it has much larger fuel bowls that don't leak down. 2) Install a marine grade electric fuel pump to replace the mechanical pump. Your choice. A lot of owners do both and have the equivalent of TKS turn key starting.
 
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