need help up here in boston

[bill1967hump]

the boat will run if i hold down choke plate covering one of the two holes on the choke plate, can run it for a while this way. but the second i take my thumb off the plate it dies.

 

[NHGuy]

Re: need help up here in boston

What year & engine?

 

[ChrisCraftJohnny]

Re: need help up here in boston

Hi,

Do you mean when you open the choke plate by hand the engine idles OK, right?

Then, when you release the choke plate the engine dies, Correct?

If this is the case, you have a bad choke. I don't know if you have a electric or vacuum actuated choke. I just replaced my Mercarb 2BBL electric choke this season. It's very easy.

For a quick fix so you can get out on the water: You can safety wire the choke plate open. Just make sure you warm up the engine on the trailer at home with muffs on before you head for the launch. Cary a can of starter fluid to help ensure any cold starting issues on the water. You see that choke closing when the engine is warm is causing a lack of air flow into the carb. At sea level an engine burns Approx. 1500 gallons of air to one gallon of gas. No air, no go. That's why no internal combustion engines for NASA in space! LOL

Only do this latter method if you feel confident with the boat.

Johnny.

 

[HT32BSX115]

Re: need help up here in boston

For a quick fix so you can get out on the water: You can safety wire the choke plate open.

Or you can do what I did and PERMANENTLY adjust the choke "open" and disconnect it.

I only boat in warm weather. I don't need it!

OTOH, if it will only run when you hold the choke plate closed, then you probably need to rebuild the carb......


Cheers,


Rick

 

[ChrisCraftJohnny]

Re: need help up here in boston

Rick,

You have no hard starting issues with your engine when cold? (ambient temp)

I know you can get a carbed engine started without a choke. But the idea of an automatic choke is so you do not have to goose or mess with the carb/throttle to get the engine started. Also, when an engine is cold,(ambient temp) The engine needs a richer mix, hence the choke. But each to his own I guess.

Johnny

 

[HT32BSX115]

Re: need help up here in boston

Hi Johnny,

I have disabled the choke on every boat I've had. It's just not a problem. Yes, I need to pump the throttle a couple of times to get get it running and I have to run it at a fast idle but it's never been a problem with this 454 or my previous 150 Mercruiser (230 cu-in 6)

Once it's warmed up it starts every time, first time. And I don't have to wait for the choke to "run its course" each time. The engine is closed cooled so the engine warms up VERY quickly and stays warmer longer after shutdown.

If I was going to operate in cold weather, I might have a different plan but it works just fine without it....Even in Western Wa! The ideal setup would be a manual choke of course.


Cheers,


Rick

 

[sea wolf]

Re: need help up here in boston

Have you done any of the things suggested in your other thread? What do u mean that u can run it for a while this way?

 

[libellav15]

Re: need help up here in boston

aaaaaahh - manual choke - pull the knob when needed - those were the days

the laziness of mankind - electric windows etc etc just more things to go wrong - and more appointments in the workshop's diary

 

[bill1967hump]

Re: need help up here in boston

ive tried all, i mean that if i prime carb by throttling a few times and have somebody else start it i can keep the boat running by holding the choke plate closed covering on of the holes on the plate with my thumb. while the engine is running i can kkep it running by slighltly opening it or closing it depending on how the engine sounds. if i open it a little to much it will start to stall, if i keep it completely closed for to long it sounds poorly to. i dont know what to do next. is it fuel or vacum? gas is being delivered, i got spark,and the motor will start if i hold the choke closed. thanks for your help

 

[ChrisCraftJohnny]

Re: need help up here in boston

Billy Beantown....

Sounds like time for a rebuild of the carb. The Choke plate should not cause all those runability problems you are having. More like improper mixture setting or bad float/adjustment or sticking check ball etc.

If it's a Mercarb 2BBL it's pretty easy to rebuild. I did mine last winter. Needed a new choke $55.00, a Merc (not Sierra) rebuild kit ($75.00) and lots of cleaning in carb dip (autozone $20.00) to remove internal gunk and the PO's heavy touch with phantom black on the outside.

Makes a huge difference when it's done. Took my time and made sure everthing was super clean and set to factory specs. After about 2 hours of masking everywhere with blue masking tape, I put a nice light coat of Merc Phantom black. The carb not only runs the engine 100% better, but also looks new.

What ever you do, don't buy a Sierra kit. And if it"s a Quadra-Jet, be xtra careful or really consider someone who knows Q-jets inside and out. And remember, no Automotive parts for the carb rebuild.

Johnny

 

[bill1967hump]

Re: need help up here in boston

thats just it, i just sent the carb out to be rebuilt by the carb specialist in georgia. cost me 300.00. that carb was bench tested and set before being sent to me.(at least thats what they told me)

 

[sea wolf]

Re: need help up here in boston

In your other thread u said that u backed out the idle mixture screws 9 turns each. Why? Does the choke close when u pump the throttle when the engine is cold? Mind telling us what setup u have?

 

[bill1967hump]

Re: need help up here in boston

i backed the screws out because someone told me that when you hold the choke plate down it creates a "rich" condition. they suggested to me to back out ths screws to make the carb run "richer". the screws were set from the rebuild place, one was 3 turns and the other was two turns. i ended up bringing the boat to a marine repair place last night. i appreciate evryones help. hopefully its just something small that was just over looked, but thats never the case lol. i should know by the end of the day what the problem is. i,ll post it when i found out