BajaKevin

iTrader: (1)

I just bought a 1990 Baja with a mercruiser 454 and bravo combo. It has the quadrajet carb and I'm having some issues with it. The previous owner had paper work showing it was rebuilt in March of this year and it looks like it was but I believe there is a part from the choke assembly missing like a spring or something. I'm mechanically inclined and know my way around EFI engines but am a complete noob when it comes to carbs. Can anyone make anything out from these pics and determine if there is something missing and if so point me in the direction of to get the missing part. If nothing is missing please forgive this post lol.

compedgemarine

first question would be what is it doing that is wrong? it is a pretty simple system, the coil mounted to the intake has a bi-metal coil that moves when the intake crossover heats up, that moves the choke off. the white plastic vacuum pod is part of the choke pull off. when the engine starts and vacuum comes up it pulls in and the lever will open the choke a small amount so the engine gets a little air as it warms up.

BajaKevin

iTrader: (1)

My choke is non functional at all. There is nothing hooked to the coil that moves it when heated up. I can't tell if it's just not connected properly or if there is something missing from the puzzle.

antisocial

the pics are alittle rough but I think the coil part isnt in the right place

antisocial

i think that spring piece on bottom is wrong

compedgemarine

best I can tell from the pics it looks like there is a rod coming from the coil and attached at the top. is that correct? if that rod is hooked to the coil you should be able to move the lever there outside the carb and see the coil move. from there the shaft that the lever is on goes into the carb body into a cavity where the rod coming down from the choke plate. inside there is a little lever that has to be put in place when the choke lever assembly is put on. some times the upper rod is not in the lever or someone did not get the lever on right when they put it back together.

Griff

Save yourself the trouble of messing with it. Boats really don't need a choke.
Just wire the butterfly open and run the boat at 1000-1100rpms for 30-60 seconds when you start it.

Budman II

iTrader: (1)

You will be able to tell if this part is missing if the choke butterfly just flops open and closed with no resistance. If the internal lever is not connected to the external choke shaft, you will probably have to pull the carburetor and hold it on its side to get it in place. This is probably one of the trickiest parts of reassembling a Q-jet.

As Griff said, if you just want to get out on the water quickly, and it is warm in your area, you may be able to get by with just wiring the choke butterfly open. One other thing to check is that the rod going to the secondary air flap is not keeping the secondaries from operating when the engine is warmed up. That is the new appearing shiny rod that goes from choke pulloff to the lever on the secondary flap. This is designed to keep the secondaries from opening when the choke is closed. To do so would cause a huge lean spot in a cold engine.

MEANGREEN231

Agreed, on my 750's I pulled all the choke hardware off.

NHGuy

It looks as if the previous owner did a choke-otomy. IF you want to fix it you'll need the linkage that goes down to the coil on top of the intake, and a fork that rides against the bend on the rod that comes out of the vacuum break.
The vac break pulls off the choke if you rev it before the motor has warmed enough for the coil to open the choke. It also damps the opening of the secondary air doors when you go to larger throttle openings (like wide open). Without that the carb will bog mercilessly.
Just wire it so the choke stays open til you decide what to do. Pump the gas before cold starts and feather the throttle till she settles and runs.
If you fix it, you can get parts and a book plus personal advice from Cliff Ruggles. He is a q-jet specialist and extremely knowledgeable. Check out cliffshighperformance.com