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AQ225B-manual choke conversion?

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lodka

Member
I have a 32' Coronet with twin AQ225B's (305ci/5.0L). One engine is very difficult to start cold, impossible to start warmed up, and tends to flood easily. I'm not looking forward to another summer of this and I'm wondering if a manual choke is a possible solution. I ask those with experience if this is a practical idea?
Thanks for any advice.
 
I once bought a 25ft Bertram that the previous owner had "given up" on. Exact same starting issues with one of its engines ( 6 cylinder In line Chevys). It turned out that the thermostatic coiled spring in one of the chokes had been installed backwards by the "certified Mercruiser mechanic" who had charged a generous amount to "rebuild" the carbs ( I saw the bill). I found out this was the problem as follows: I waited for a cold morning and removed both flame arrestors. I went to the helm and cycled both throttles wide open then shut, then opened slightly. I looked down throat of both carbs and saw that one choke was closed, and one was wide open, i.e., choke plate vertical. I reached in a finger to move the open choke plate thinking it was frozen and discovered that it was free and moved freely, but snapped back to vertical soon as I let my finger off. I propped the choke half shut and was able to get the engine to start and warm up, HOWEVER as the engine warmed up the choke CLOSED and engine kept flooding at idle. I removed the black plastic cover plate of the choke spring housing and removed the spring (it slides out) and installed in in reverse. Problem solved.

That may not be you exact problem, but chokes aren't rocket science and fixing yours will be less work that trying to jury rig a manual one. Buying a cable for a manual choke that won't rust out in a season will cost you a few bucks as well.
 
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Thank you both. I will definitely not install manual choke controls. Capt Bob, that's an interesting story and could very well be the same problem as mine. Oddly enough (or maybe not so oddly) the carb on the engine that is difficult to start was rebuilt by the previous owner. The other carb has never been rebuilt, as far as I know, and that engine is the least troublesome to start.
Rick, thanks for the links. In fact, the choke stoves each have the coil springs, but I don't see anything like them in the diagrams. I don't want to put words in your mouth; I only want to understand. Are you saying that the choke stoves with the bimetal springs are wrong for this engine? Should there be no electrical connections to the carbs?
Thanks again to you both.
 
The "Helix" is the bi-metal coil spring unit that functions due to change in temperature.... whether heated by the electric element, or by the exhaust-cross-over "well" in the intake manifold.
This unit pulls the choke plate "open" upon warm-up..... and also closes the choke plate upon cool-down.

The "B" engines are older (1975, 1976, 1977 etc), and I'd not be surprised if the Helix units will remote... (as in the intake manifold "well")
The MarinePartsEurope web site images for the "B" engines do not help us.

What I'm suggesting is...... that you correct what/which choke system you now have.... but I'd rather see you with the electric units.


,
 
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lodka

RicardoMarine said:
The "Helix" is the bi-metal coil spring unit that functions due to change in temperature.... whether heated by the electric element, or by the exhaust-cross-over "well" in the intake manifold.
This unit pulls the choke plate "open" upon warm-up..... and also closes the choke plate upon cool-down.

The "B" engines are older (1975, 1976, 1977 etc), and I'd not be surprised if the Helix units will remote... (as in the intake manifold "well")
The MarinePartsEurope web site images for the "B" engines do not help us.

What I'm suggesting is...... that you correct what/which choke system you now have.... but I'd rather see you with the electric units.


,
Click to expand...
That's very helpful, thank you! The choke heaters on my engines are in sheet metal housings, mounted pretty much down on the manifold and open at the top, so that you can see into them from above. (They're different from all the automotive automatic chokes I've seen. ) I'll check for +12v at ignition-on, and go from there. If I can find replacments, I'll get them.
 
Re: lodka

lodka said:
The choke heaters on my engines are in sheet metal housings, mounted pretty much down on the manifold and open at the top, so that you can see into them from above. (They're different from all the automotive automatic chokes I've seen. ) I'll check for +12v at ignition-on, and go from there. If I can find replacments, I'll get them.
Click to expand...
You'll see both the older Automotive and Marine Q-jets using either the electric choke units, or the mechanical choke units.
Either uses the Helix..... it's just that the Helix receives heat differently in each scenario.


I believe that the Q-jets for the remote Helix do not accept the Electric units.

Here's one that is being listed as OMC. I believe that this is actually an early Volvo Penta Q-jet due to the primary throttle shaft plate.
Note the fuel inlet orientation.

http://www.ebay.com/itm/like/370589288870?lpid=82


Here's a Volvo Penta Q-jet being listed by Carlos of I-5.
Again...... note the primary throttle shaft plate! This is unique to Volvo Penta
Also notice the fuel inlet orientation......... Some enter the carburetor angled towards Stbd....... some enter parallel to the engine crankshaft.

http://www.ebay.com/itm/MARINE-CARB-ROCHESTER-QUADRAJET-VOLVO-PENTA-V6-17088142-/370501642678





.
 
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Ah, ok. So much for checking the voltage at the Helix. On a slightly different subject, I note that my carbs don't have the "J" pipe at the top near the choke plate. I hope this doesn't indicate the wrong type (automotive?) carbs.
Is Carlos at I-5 considered a reliable supplier among the boating community? Let's say I order a reconditioned carb for a AQ225B-can I be sure that's what I'll get, with proper jets for that engine, etc?
Thanks for the links.
 
I hope the question about I-5 wasn't tactless in the way i worded it. I probably should have put it this way-can anyone vouch for this seller?
 
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