Carb engine owners...how many "primer pumps" before starting?

pdxsearay

Member
Jun 4, 2020
89
Boat Info
2005 Sea Ray 185 Sport
Engines
4.3 merc
Dealership told me three...is that consistent with what others do? It always works.

In case my terminology is wrong, referring to the middle-button-engaged throttle stick pumps that you do prior to starting.
 
Yup, 2-3 usually get's the job done for me. It really depends on how long it's been sitting, how far it was towed to the water, etc. (1989 4.3 merc)
 
I usually only pump once. 1995 5.7 merc
 
If it's only been a day or two, one pump, set throttle about 1/3 and it fires right up. It it has sat for a week or more, I usually crank it for about 10sec first, this fills the carburetor bowl, then I pump it one or twice and it fires right up. Every engine seems to have it's own little personality.
 
If it's only been a day or two, one pump, set throttle about 1/3 and it fires right up. It it has sat for a week or more, I usually crank it for about 10sec first, this fills the carburetor bowl, then I pump it one or twice and it fires right up. Every engine seems to have it's own little personality.
Good idea in the spring I pump many times while starting. It starts fine takes 10 to 15 seconds to start
 
If it's only been a day or two, one pump, set throttle about 1/3 and it fires right up. It it has sat for a week or more, I usually crank it for about 10sec first, this fills the carburetor bowl, then I pump it one or twice and it fires right up. Every engine seems to have it's own little personality.

You have the boat in gear when you start it?
 
After having my outboard in the up position between use, I squeeze the bulb until it becomes firm and move the throttle about one third forward in neutral. It still takes 5 to 7 turns of the key until the engine starts. Would pumping the throttle 2 to 3 times before I turn the key reduce the number of times I have to turn the key before it starts?
 
No, use the neutral button to advance the throttle.

yeah that’s what I thought. When you say “set the throttle at 1/3 and it fires up” you mean throttle sticks stays at 1/3 forward but with middle neutral button pushed in?

That had not occurred to me. I thought it was pump & then back to neutral. My boat generally starts reliably but once every 10 times or so it takes 5 key turns, that might help for those occasions.
 
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After having my outboard in the up position between use, I squeeze the bulb until it becomes firm and move the throttle about one third forward in neutral. It still takes 5 to 7 turns of the key until the engine starts. Would pumping the throttle 2 to 3 times before I turn the key reduce the number of times I have to turn the key before it starts?
All the old 2 strokes I've owned had electric chokes. Push the key in as you turn it to crank.
 
After having my outboard in the up position between use, I squeeze the bulb until it becomes firm and move the throttle about one third forward in neutral. It still takes 5 to 7 turns of the key until the engine starts. Would pumping the throttle 2 to 3 times before I turn the key reduce the number of times I have to turn the key before it starts?

I pumped the throttle 3 times today before I turned the key. I set the throttle at 1/3 in neutral before turning the key. The boat started on key turn number 4. Pumping the throttle definitely helped. I'm going to try pumping the throttle 5 times before turning the key the next time I take the boat out.
 
If the boat sits for a week it takes some cranking to fill the carb bowls. I expect I have the Rochester carb leak down issue. Starts no problem though. If I have run it the day or two before one pump to set the choke and it starts right away.
 
When we had our 1986 250DA I would pump it once then set it to about 1/3 throttle and it would fire right up. Our Crownline is carb'd but has a TKS solenoid that richens the mixture on a cold start so no throttle is needed.

Carb'd engines will typically apply the choke flap on a thermostatic choke with the first pump. Any more pumps is adding fuel to the engine. I have had cars that needed 3 pumps. It really depends on the application and the settings on the carb. Do what works for you.
 
Folks on this thread ...one more question from a first time boat owner. How long do you hold the key in the crank position when starting after pumping the throttle a few times ? If I’m only doing 1-2 seconds is that too short?

Boat engines have more of a “grinding” sound than cars which I’m still getting used to. Do you also pump while cranking or does leaving the throttle on with neutral button on do enough ? Is there any way to “flood” the engine where too much pumping or neutral throtttle is too much ?

My engine has yet to “not start” on me and runs great once on, but last time we were out it definitely took a minute or two after an hour of anchoring. I know it’s not the battery. I’ve noticed a recurring issue of it starts ok at first , we cruise for 10-20m, anchor for a whole , and re starting is much harder. Trying to figure out if more pumps is a good or bad idea. 05 4.3 carb merc here with 120 hours total. Thanks!
 
Folks on this thread ...one more question from a first time boat owner. How long do you hold the key in the crank position when starting after pumping the throttle a few times ? If I’m only doing 1-2 seconds is that too short?

Boat engines have more of a “grinding” sound than cars which I’m still getting used to. Do you also pump while cranking or does leaving the throttle on with neutral button on do enough ? Is there any way to “flood” the engine where too much pumping or neutral throtttle is too much ?

My engine has yet to “not start” on me and runs great once on, but last time we were out it definitely took a minute or two after an hour of anchoring. I know it’s not the battery. I’ve noticed a recurring issue of it starts ok at first , we cruise for 10-20m, anchor for a whole , and re starting is much harder. Trying to figure out if more pumps is a good or bad idea. 05 4.3 carb merc here with 120 hours total. Thanks!
Sounds like there may be something that needs fixing on the carb. It could need a rebuild and choke adjustment. My 23 year old 454s only need pumping after it is sitting for a week or more. If I have run it the day before it starts with one pump of the throttle and fires almost instantly. If it has been only turned off for a few hours, I generally just hit the start buttons with no pump and it fires up right away.
 
Folks on this thread ...one more question from a first time boat owner. How long do you hold the key in the crank position when starting after pumping the throttle a few times ? If I’m only doing 1-2 seconds is that too short?

Boat engines have more of a “grinding” sound than cars which I’m still getting used to. Do you also pump while cranking or does leaving the throttle on with neutral button on do enough ? Is there any way to “flood” the engine where too much pumping or neutral throtttle is too much ?

My engine has yet to “not start” on me and runs great once on, but last time we were out it definitely took a minute or two after an hour of anchoring. I know it’s not the battery. I’ve noticed a recurring issue of it starts ok at first , we cruise for 10-20m, anchor for a whole , and re starting is much harder. Trying to figure out if more pumps is a good or bad idea. 05 4.3 carb merc here with 120 hours total. Thanks!


As stated above, with a warm or hot motor, just turn the key, no pumps.

On a cold motor, as few pumps as necessary.
trial and error will give you the answer.

As far as 1-2 seconds of cranking, that seems short to me. Holding the key around 5 seconds seems more reasonable.


Every boat is different, you have to figure out what works for you.
 
Cold engine - crank 5-10sec, pump throttle and it fires up, warm just bump the key and it starts like a car.
 
I have a four barrel Rochester car with the manual choke on my 5.7. if the engine has been run within the last day or so it will usually fire right up on the first or second crank.

If the engine has been cold and sitting for a week then it will not start for me unless I pull the manual choke and give it one third throttle and then I release the choke let it idle on its own for a few seconds then go down to neutral and it's fine.

I'm wondering if the people that say they only have to give it two or three pumps and fires right up are the people that have automatic electric chokes.


mine never fires the first time if it's been sitting for a week I always have to use the manual choke regardless of temperature unfortunately.
 
I pumped the throttle 3 times today before I turned the key. I set the throttle at 1/3 in neutral before turning the key. The boat started on key turn number 4. Pumping the throttle definitely helped. I'm going to try pumping the throttle 5 times before turning the key the next time I take the boat out.

I figured out what I was doing wrong. I was pushing the key in when the key was in the "off" position. This wasn't doing anything. The trick is to turn the key to the "on" position (NOT "start") and push in for about 4 seconds. With the throttle set at 1/3 in neutral the engine is starting every time on the first turn of the key after pushing the key in for about 4 seconds in the "on" position. I also make sure the fuel bulb is firm before starting. Pumping the throttle is not required.
 

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