Q-jet choke coil

[erikgreen]

What would the engine problems be of having a qjet carb with the choke coil detached?

Edit: I don't think that's the right name for the part. I'm talking about a spiral spring about a half inch wide coiled vertically and attached on the side of the carb near the base. It's covered in a little sheet metal housing.

I noticed today that even though I connected it during the rebuild of my motor last summer, the coil came loose sometime after and it's now fully broken off and dangling on the side of the carb along with the cover. I wonder if it ever worked?

Edit 2: Here's a pic from my rapido longblock thread... you can see the sheet metal housing in this one:

This is on my Sea Ray SRV 210 with a rapido longblock 350 and mostly new bolt-ons, but the distributor and intake are from the old 305. It ran ok last summer, but I had the wrong prop on and couldn't get beyond 3200 rpm... which I thought was odd because I was underpropped.

I presume I can replace this with a standard Qjet part?


Erik

 

[Fishermark]

Re: Q-jet choke coil

That is a bi-metal spring that helps open the choke on a mechanical choke when the engine heats up. Without it, the choke will not open fully when warm and the engine will run rough and rich - it at all.

 

[erikgreen]

Re: Q-jet choke coil

Okay... but I thought Mercruiser marine engines had an electric choke? I'll take a better pic of it tonight, just to let people see what I have.

Erik

 

[Fishermark]

Re: Q-jet choke coil

Depends on the vintage. I know the original carb on my dad's boat (Mercruiser) had a mechanical choke that required the heat tube. When the carb shop rebuilt the carb they put on an electric element instead. But that style is fitted on the top / side of the carb. If I'm not mistaken, your carb has a rod which is connected to the bi-metal spring - correct?

 

[bruceb58]

Re: Q-jet choke coil

I have seen that type before. It happened to be on a mid 70's OMC with a Q-Jet. They take a long time to heat up and remove the choke.

 

[Silvertip]

Re: Q-jet choke coil

If the exhaust crossover (provides manifold and carb heat) is blocked for whatever reason (intake manifold gasket doesn't have the crossover hole), the choke coil will indeed take a long time to heat up. You do not have an electric choke.

 

[Don S]

Re: Q-jet choke coil

You look to be living dangerously in how you have your engine stand hooked up. Especially with all the weight of the manifolds and everything else.
You should be bolted to the stand in the holes shown below. You are really asking a lot of the stand and threads.

 

[JustJason]

Re: Q-jet choke coil

you can just make it out from the picture... its one of the cheaper stand... with just one leg in the center... versus 2 on the outside.... hope your using grade 8 bolts.

 

[erikgreen]

Re: Q-jet choke coil

You look to be living dangerously in how you have your engine stand hooked up. Especially with all the weight of the manifolds and everything else.
You should be bolted to the stand in the holes shown below. You are really asking a lot of the stand and threads.

Thanks Don... fortunately I made it through the assembly and install... I had bought and used some grade 8 bolts for holding the engine to the stand, so maybe that helped.

Anyway, I'll keep that in mind for the next time I use the stand.

 

[erikgreen]

Re: Q-jet choke coil

If the exhaust crossover (provides manifold and carb heat) is blocked for whatever reason (intake manifold gasket doesn't have the crossover hole), the choke coil will indeed take a long time to heat up. You do not have an electric choke.

Well, I did manage to get it screwed back on sort of... and I know the exhaust passages aren't blocked, because I measured their temp last year near 200F.

But what are we talking about when we say "a long time".... would I be better off replacing the carb (and intake) with something more modern? Or will this work if I can keep it screwed in place?

 

[erikgreen]

Re: Q-jet choke coil

Depends on the vintage. I know the original carb on my dad's boat (Mercruiser) had a mechanical choke that required the heat tube. When the carb shop rebuilt the carb they put on an electric element instead. But that style is fitted on the top / side of the carb. If I'm not mistaken, your carb has a rod which is connected to the bi-metal spring - correct?

Yes, correct. So I can get a conversion kit or some parts somewhere, then... that's good.

 

[erikgreen]

Re: Q-jet choke coil

Okay, I did a little research and I think I can answer my own question now

This type of choke is called a "divorce choke" because the mounting for the bi-metal coil spring is "divorced" from the carb and instead is on the intake manifold. It's a type of automatic choke that's activated by engine heat, the non divorced type being a similar spring mounted on the carb itself.

It can be converted to electric choke with about a $50 kit, or else the spring can be twisted/removed to disable the choke (not recommended).

I'm looking into ordering a conversion kit that will make my choke electric. Long term I'm thinking about replacing the intake and carb with something that's not a pile of rusting parts, but we'll see how this works for now.

Erik

 

[krisnowicki]

Re: Q-jet choke coil

when you find it let me know I have a mech choke and want to convert bad .... Thanks

 

[erikgreen]

Re: Q-jet choke coil

Well, I'm gonna order one of these:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=140219829444

I asked the seller and he says it will work on a marine 350 if the manifold has a bolt location for a choke (which it does for the divorce choke).

Erik