Hard starting issues

Hard starting issues

Joined: January 4th, 2006, 10:39 pm

January 23rd, 2006, 1:05 pm #1

I sat in the marina this weekend and ran the engines, ha ha, because there was no need to venture out onto the Tennessee River in the pouring rain. Problem is, the motors don't want to start very well. I've checked fuel filters, the ignition points appear to be properly set becuase once started, everything works well. Several guys came over and listened to the motors running, they sure sound good under the roof of the marina. Very few people were actually going out this weekend, most of the action was right in the slip.

Any tips on the starting issues?

Thanks,

Howard
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Paul
Paul

January 23rd, 2006, 3:07 pm #2

Hi Howard,

I think you’re running 427s with carter carbs, so if I’m wrong please let me know as the answer may be different.

First thing I’d do would be to toss those ignition points and install Pertronix Ignition. It’s simple, cheap, and very reliable.

Secondly, I would wire the chokes on your carters wide open, as they’re more trouble than they are helpful, because once the motor is hot and you’re out running, if they malfunction, it can lead to a very rich charge and possible flooding. I’d rather have more difficulty starting, than difficulty trying to figure out what those crappy choke assemblies are trying to do..

Electric choke kits, and electric choke carb replacements are available, but in reality these run no better when the engine is hot, than the stock carter does. Rebuilding these old carbs is a simple task. You might consider doing this before next season.
I think your starting problem is generic with the carter carb. In other words, I believe just about everyone with an original Commander has the same issue. The carbs don’t atomize well at cranking speed. The carters will either slightly drain down or evaporate fuel from the bowl, and this makes starting a bit of a challenge. You’ll notice that if you run in the morning, and then try to start in the afternoon, the motors will probably fire right up because the carbs are still primed up and ready to run. There is a very simple solution, however, and it is NOT electric fuel pumps. More about that later.

The solution is to pump the throttles and then catch the motor before it stumbles. It is very simple but it takes a bit of practice to know just how many pump strokes it will take, depending on the carb and the time it has been sitting up.

Knowing the fuel may be low in the carb bowl if the boat has been sitting a while, if I have not run the motors for a while, I always pump the throttles 10 to 15 times. If it’w been two weeks, perhaps more. What this does, is put enough gas vapor into the intake manifold to cause the cylinders to light off, but it also further drains down the bowl. This vapor is getting to the motor from raw gas dumped into the intake manifold instead of the carb being primed by continuous cranking up to the point where it will atomize fuel enough to start. This assumes your chokes are junk like 99.9% of all marine chokes are on Carters. If you get enough raw gas pumped into the intake manifold, the motors will catch just fine, but the fuel bowl may take just a few seconds to fill up with that fuel pump pumping away.

What I do is crack the throttles open far enough to provide a 1500 RPM engine speed. This takes a little practice. When the motors start, then will very quickly build up fuel pressure, but they may want to stumble a bit, so be prepared to jab another squirt of gas to keep engine speed up high enough for that initial fire up. Crank crank, varooooooommmmmm, burble burble, start to cough just a bit, give it a bit more gas before it stalls, and varoooooommmmmm and running fine at 1500 RPM fast warm up idle speed for a short while, and then back off so as to not scare all the rest of the people out of the marina. It may take a few times to know just how much fuel to pump, depending on how long the motor has been sitting.

I’ve heard a lot of comments about electric fuel pumps, but I don’t like them on a boat. There are literally MILLIONS of cars still out there running with traditional fuel pumps, and just doing fine, pumping a lot more fuel than our 300 hp detuned 427 motors need at a max of (only) 4000 RPM. This is 2000 RPM less than the factory warranted speed of some of the higher performance motors, by the way, and I’m sure the carbs and pumps were different too, but the point is, 4000 RPM really doesn’t put that much of a demand on a fuel pump.

I don’t like electric pumps because they’re one more electrical component tied to switches, connections, batteries, that can corrode in a marine environment and fail. The mechanical pump is a slave situation, and it is almost “dead reliable”. Why go to something that certainly has a higher probability of failure? Answer: 427 fuel pumps are difficult to get to, and this is the reason some go to the electric pumps. If you use an electric pump, in my humble opinion you MUST use an oil pressure switch to shut off the pump if pressure drops with the motors running, to avoid pumping raw gas into the boat in the event of some sort of engine failure or emergency situation, and this is just one more reliability issue that can fail and be very tough to diagnose.

You can install a fuel pressure gauge to tell exactly how your pumps are working, but do NOT install the direct pressure type on a boat, because that is one more very serious safety issue you will be flirting with and there is no need to do so. Also, I would think a sharp USCG or marine surveyor inspector would see this and write you up. If you use a fuel pressure gauge, in my opinion, you must use one with an electric sending unit.

I do not view electric pumps to be the panacea some do. I view them to be sort of an easy way out approach to not replacing the standard pump. I would rather adapt to the starting procedure noted, than have the danger and potential unreliability factor associated with so many additional electric connections, etc.

If you want instant starting you can go with a new marine carb (“marine”) with electric chokes, or you can simply adapt to the routine I’ve noted here. Personally, on a boat I like the “keep it simple” format, and with fewer things to go wrong, fewer things “will” go wrong. I understand there have been elec fuel pumps in operation (often as the “cheaper” and “easier” solution) for years, but I personally don’t like the corrosion issue in a marine environment, and I also don’t like the potential safety issue.

Hope this helps a bit.

Regards,
Paul
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Dave Mehl
Dave Mehl

January 23rd, 2006, 3:40 pm #3

....generally works great, except in colder weather I have to pump them more. My chokes are gone too, don't think it was a good design in the first place. I agree the electric fuel pumps can be very convenient, but I also do not like the added things that can go wrong, and I also believe they represent a bit more of a safety issue, not just from potential fire, but from the corrosion and reliability factor too.

Dave
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Joined: January 4th, 2006, 10:39 pm

January 23rd, 2006, 5:29 pm #4

it's comforting to know I'm not the only one with this problem.

Howard
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Joined: September 16th, 2005, 3:49 pm

January 23rd, 2006, 5:32 pm #5

Hi Howard,

I think you’re running 427s with carter carbs, so if I’m wrong please let me know as the answer may be different.

First thing I’d do would be to toss those ignition points and install Pertronix Ignition. It’s simple, cheap, and very reliable.

Secondly, I would wire the chokes on your carters wide open, as they’re more trouble than they are helpful, because once the motor is hot and you’re out running, if they malfunction, it can lead to a very rich charge and possible flooding. I’d rather have more difficulty starting, than difficulty trying to figure out what those crappy choke assemblies are trying to do..

Electric choke kits, and electric choke carb replacements are available, but in reality these run no better when the engine is hot, than the stock carter does. Rebuilding these old carbs is a simple task. You might consider doing this before next season.
I think your starting problem is generic with the carter carb. In other words, I believe just about everyone with an original Commander has the same issue. The carbs don’t atomize well at cranking speed. The carters will either slightly drain down or evaporate fuel from the bowl, and this makes starting a bit of a challenge. You’ll notice that if you run in the morning, and then try to start in the afternoon, the motors will probably fire right up because the carbs are still primed up and ready to run. There is a very simple solution, however, and it is NOT electric fuel pumps. More about that later.

The solution is to pump the throttles and then catch the motor before it stumbles. It is very simple but it takes a bit of practice to know just how many pump strokes it will take, depending on the carb and the time it has been sitting up.

Knowing the fuel may be low in the carb bowl if the boat has been sitting a while, if I have not run the motors for a while, I always pump the throttles 10 to 15 times. If it’w been two weeks, perhaps more. What this does, is put enough gas vapor into the intake manifold to cause the cylinders to light off, but it also further drains down the bowl. This vapor is getting to the motor from raw gas dumped into the intake manifold instead of the carb being primed by continuous cranking up to the point where it will atomize fuel enough to start. This assumes your chokes are junk like 99.9% of all marine chokes are on Carters. If you get enough raw gas pumped into the intake manifold, the motors will catch just fine, but the fuel bowl may take just a few seconds to fill up with that fuel pump pumping away.

What I do is crack the throttles open far enough to provide a 1500 RPM engine speed. This takes a little practice. When the motors start, then will very quickly build up fuel pressure, but they may want to stumble a bit, so be prepared to jab another squirt of gas to keep engine speed up high enough for that initial fire up. Crank crank, varooooooommmmmm, burble burble, start to cough just a bit, give it a bit more gas before it stalls, and varoooooommmmmm and running fine at 1500 RPM fast warm up idle speed for a short while, and then back off so as to not scare all the rest of the people out of the marina. It may take a few times to know just how much fuel to pump, depending on how long the motor has been sitting.

I’ve heard a lot of comments about electric fuel pumps, but I don’t like them on a boat. There are literally MILLIONS of cars still out there running with traditional fuel pumps, and just doing fine, pumping a lot more fuel than our 300 hp detuned 427 motors need at a max of (only) 4000 RPM. This is 2000 RPM less than the factory warranted speed of some of the higher performance motors, by the way, and I’m sure the carbs and pumps were different too, but the point is, 4000 RPM really doesn’t put that much of a demand on a fuel pump.

I don’t like electric pumps because they’re one more electrical component tied to switches, connections, batteries, that can corrode in a marine environment and fail. The mechanical pump is a slave situation, and it is almost “dead reliable”. Why go to something that certainly has a higher probability of failure? Answer: 427 fuel pumps are difficult to get to, and this is the reason some go to the electric pumps. If you use an electric pump, in my humble opinion you MUST use an oil pressure switch to shut off the pump if pressure drops with the motors running, to avoid pumping raw gas into the boat in the event of some sort of engine failure or emergency situation, and this is just one more reliability issue that can fail and be very tough to diagnose.

You can install a fuel pressure gauge to tell exactly how your pumps are working, but do NOT install the direct pressure type on a boat, because that is one more very serious safety issue you will be flirting with and there is no need to do so. Also, I would think a sharp USCG or marine surveyor inspector would see this and write you up. If you use a fuel pressure gauge, in my opinion, you must use one with an electric sending unit.

I do not view electric pumps to be the panacea some do. I view them to be sort of an easy way out approach to not replacing the standard pump. I would rather adapt to the starting procedure noted, than have the danger and potential unreliability factor associated with so many additional electric connections, etc.

If you want instant starting you can go with a new marine carb (“marine”) with electric chokes, or you can simply adapt to the routine I’ve noted here. Personally, on a boat I like the “keep it simple” format, and with fewer things to go wrong, fewer things “will” go wrong. I understand there have been elec fuel pumps in operation (often as the “cheaper” and “easier” solution) for years, but I personally don’t like the corrosion issue in a marine environment, and I also don’t like the potential safety issue.

Hope this helps a bit.

Regards,
Paul
I am "old school" in my fear and respect for the explosive properties of gasoline, and don't prefer an electric pump in a closed environment, nor would I ever use a mechanical fuel pressure gauge. I would use one with an electric sending unit, as they are pretty dormant, and would not represent a danger or a reliability issue.

Charlie
Commander35
Cape Vincent, NY
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wot
wot

January 23rd, 2006, 6:39 pm #6

Hi Howard,

I think you’re running 427s with carter carbs, so if I’m wrong please let me know as the answer may be different.

First thing I’d do would be to toss those ignition points and install Pertronix Ignition. It’s simple, cheap, and very reliable.

Secondly, I would wire the chokes on your carters wide open, as they’re more trouble than they are helpful, because once the motor is hot and you’re out running, if they malfunction, it can lead to a very rich charge and possible flooding. I’d rather have more difficulty starting, than difficulty trying to figure out what those crappy choke assemblies are trying to do..

Electric choke kits, and electric choke carb replacements are available, but in reality these run no better when the engine is hot, than the stock carter does. Rebuilding these old carbs is a simple task. You might consider doing this before next season.
I think your starting problem is generic with the carter carb. In other words, I believe just about everyone with an original Commander has the same issue. The carbs don’t atomize well at cranking speed. The carters will either slightly drain down or evaporate fuel from the bowl, and this makes starting a bit of a challenge. You’ll notice that if you run in the morning, and then try to start in the afternoon, the motors will probably fire right up because the carbs are still primed up and ready to run. There is a very simple solution, however, and it is NOT electric fuel pumps. More about that later.

The solution is to pump the throttles and then catch the motor before it stumbles. It is very simple but it takes a bit of practice to know just how many pump strokes it will take, depending on the carb and the time it has been sitting up.

Knowing the fuel may be low in the carb bowl if the boat has been sitting a while, if I have not run the motors for a while, I always pump the throttles 10 to 15 times. If it’w been two weeks, perhaps more. What this does, is put enough gas vapor into the intake manifold to cause the cylinders to light off, but it also further drains down the bowl. This vapor is getting to the motor from raw gas dumped into the intake manifold instead of the carb being primed by continuous cranking up to the point where it will atomize fuel enough to start. This assumes your chokes are junk like 99.9% of all marine chokes are on Carters. If you get enough raw gas pumped into the intake manifold, the motors will catch just fine, but the fuel bowl may take just a few seconds to fill up with that fuel pump pumping away.

What I do is crack the throttles open far enough to provide a 1500 RPM engine speed. This takes a little practice. When the motors start, then will very quickly build up fuel pressure, but they may want to stumble a bit, so be prepared to jab another squirt of gas to keep engine speed up high enough for that initial fire up. Crank crank, varooooooommmmmm, burble burble, start to cough just a bit, give it a bit more gas before it stalls, and varoooooommmmmm and running fine at 1500 RPM fast warm up idle speed for a short while, and then back off so as to not scare all the rest of the people out of the marina. It may take a few times to know just how much fuel to pump, depending on how long the motor has been sitting.

I’ve heard a lot of comments about electric fuel pumps, but I don’t like them on a boat. There are literally MILLIONS of cars still out there running with traditional fuel pumps, and just doing fine, pumping a lot more fuel than our 300 hp detuned 427 motors need at a max of (only) 4000 RPM. This is 2000 RPM less than the factory warranted speed of some of the higher performance motors, by the way, and I’m sure the carbs and pumps were different too, but the point is, 4000 RPM really doesn’t put that much of a demand on a fuel pump.

I don’t like electric pumps because they’re one more electrical component tied to switches, connections, batteries, that can corrode in a marine environment and fail. The mechanical pump is a slave situation, and it is almost “dead reliable”. Why go to something that certainly has a higher probability of failure? Answer: 427 fuel pumps are difficult to get to, and this is the reason some go to the electric pumps. If you use an electric pump, in my humble opinion you MUST use an oil pressure switch to shut off the pump if pressure drops with the motors running, to avoid pumping raw gas into the boat in the event of some sort of engine failure or emergency situation, and this is just one more reliability issue that can fail and be very tough to diagnose.

You can install a fuel pressure gauge to tell exactly how your pumps are working, but do NOT install the direct pressure type on a boat, because that is one more very serious safety issue you will be flirting with and there is no need to do so. Also, I would think a sharp USCG or marine surveyor inspector would see this and write you up. If you use a fuel pressure gauge, in my opinion, you must use one with an electric sending unit.

I do not view electric pumps to be the panacea some do. I view them to be sort of an easy way out approach to not replacing the standard pump. I would rather adapt to the starting procedure noted, than have the danger and potential unreliability factor associated with so many additional electric connections, etc.

If you want instant starting you can go with a new marine carb (“marine”) with electric chokes, or you can simply adapt to the routine I’ve noted here. Personally, on a boat I like the “keep it simple” format, and with fewer things to go wrong, fewer things “will” go wrong. I understand there have been elec fuel pumps in operation (often as the “cheaper” and “easier” solution) for years, but I personally don’t like the corrosion issue in a marine environment, and I also don’t like the potential safety issue.

Hope this helps a bit.

Regards,
Paul
Why electric fuel pumps? Sounds like trouble to me. Even NASCAR uses mechanical fuel pumps.

But, for your info:

ABYC Standards, Section H-24 Gasoline Fuel Systems

24.14.8 Electric fuel pumps, if used, shall be independently supported and located within 12 inches (305mm) of the engine with a maximum delivery hose length of 48 inches (1.22m).

24.14.8.1 Electrically operated fuel pump systems shall be connected to be energized only when the engine ignition switch is on and the engine is running. A momentary type override is acceptable for starting.

24.14.8.2 The outlet pressure of electrically operated fuel pumps shall be rated or controlled to the maximum carburetor fuel inlet pressure specified by the engine manufacturer.
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Bill Rayson
Bill Rayson

January 24th, 2006, 2:21 pm #7

....but I had them removed. It took a bit of hunting to find a source for marine fuel pumps, but they're certainly available. As someone noted, a mechanical fuel pump is a "dumb" device that just works automatically without the need for electrical switching, etc. I view it as a more reliable system.

BRayson
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Eric Jensen
Eric Jensen

January 24th, 2006, 3:24 pm #8

Why electric fuel pumps? Sounds like trouble to me. Even NASCAR uses mechanical fuel pumps.

But, for your info:

ABYC Standards, Section H-24 Gasoline Fuel Systems

24.14.8 Electric fuel pumps, if used, shall be independently supported and located within 12 inches (305mm) of the engine with a maximum delivery hose length of 48 inches (1.22m).

24.14.8.1 Electrically operated fuel pump systems shall be connected to be energized only when the engine ignition switch is on and the engine is running. A momentary type override is acceptable for starting.

24.14.8.2 The outlet pressure of electrically operated fuel pumps shall be rated or controlled to the maximum carburetor fuel inlet pressure specified by the engine manufacturer.
No argument from me regarding the effectiveness of mechanical fuel pumps - however, the original post was searching for reasons for hard starting. If he DOES have electric fuel pumps and they are correctly wired to an oil pressure switch, he will have to crank for several seconds to build fuel pressure. If he is pumping the throttle before he attempts to start and the carb is empty, he is not really putting significant amount (if any) of gas into the engine. It's possible that he is cranking just up to the point where he will build enough oil pressure to switch on the fuel pump. Then out of concern for his vintage starters he stops and lets them cool for several seconds. Then he repeats the process. This scenario had me scratching my head for a several weeks as to why my 427's were so reluctant to start after taking the week off. (still looking for mechanical pumps)I finally decided to wire in an intermitent override to prime the carbs before cranking. It involves a trip to the engine room before starting, but you should be down there checking things out anyway, before you fire things up. You could make an argument for an oil pressure switch on the grounds that the engine should have oil pressure before it fires up. I guess additional wear on the starter is a better bargain than wear on on internally lubricated surfaces.
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Joined: July 15th, 2005, 8:09 pm

January 24th, 2006, 10:46 pm #9

Excellent comments Eric, thanks for the post. This is of interest to just about "all" gas Commander owners, because most of us with the small block Chevy, Lincoln, and Ford motors all have essentially the same Carter AFB design, and the same crappy choke assembly.

With the Carters, it seems that everyone, regardless of mechanical or electric pumps, still has to pump the throttles to start engines without a choke. For me, the issue is knowing how much raw fuel to put into the motor to cause it to light off, as not enough won't give a rich enough charge, and too much can flood out the motor.

I added the comments about the elec fuel pump, because I really don't see them helping or hurting the situation much.

Even if the fuel bowl is not totally filled, you can still pump and prime the motor by pumping the throttles back and forth and start it. Once the motor starts for even a split second or two, the bowl is "instantly" filled with whatever thimball full it needs. At that point (first start on a cold week-end morning) the motor may stumble and stop, but I normally catch them by pumping a bit more gas one time, and at that point the fuel bowl is full and all is well.

There are some ignition mods to be used for hotter startup spark, but I think it's predominantily a fuel mix issue. Given the right mix, the engine should roar to life. The tough part is getting the right start-up mix without a choke.

My bet is, mechanical pump or electric, if the guy swaps over to a new carb with electric chokes, the motors will roar to life when he touches the starter. For me, the trick appears to be getting the same general mix by pumping raw gas into the intake manifold, and trying to start without a choke. I really don't have a problem starting my motors, because I basically pump the living daylights out of the throttles before hitting the gas. If the boat has been sitting for two weeks, I pump probably 15 to 20 time, hit the ignition, and they fire up.

More comments will be appreciated!

Regards, Paul
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Joined: January 4th, 2006, 10:39 pm

January 24th, 2006, 11:05 pm #10

I sat in the marina this weekend and ran the engines, ha ha, because there was no need to venture out onto the Tennessee River in the pouring rain. Problem is, the motors don't want to start very well. I've checked fuel filters, the ignition points appear to be properly set becuase once started, everything works well. Several guys came over and listened to the motors running, they sure sound good under the roof of the marina. Very few people were actually going out this weekend, most of the action was right in the slip.

Any tips on the starting issues?

Thanks,

Howard
here is my "cut and paste" contribution to the thread !

I'll try the 15-pump on the throttle method in cool weather next weekend and I'll let you know exactly what happens! I have standard fuel pumps by the way, not electric.

I really appreciate all the comments so far, thanks

Howard












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