AFB Carter/Weber choke problem?

[sjm32157]

I have a 1995 Mercruiser 4.3 LX 205 hp with the Y43 AFB Carter/Weber 4bbl carb. The boat runs great after it warms up but it pops and sputters (fuel starvation?) the first few minutes of operation. I have checked the front choke plates and they have about 1/8" of play. The previous owner mentioned that he rebuilt the carb himself. I'm wondering if something is out of adjustment or my electric choke is shot.

 

[Don S]

Re: AFB Carter/Weber choke problem?

I'm wondering if something is out of adjustment

Could be that, could be water in the fuel (Check & replace water seperating fuel filter) which puts water in a rebuilt carb.

I have checked the front choke plates and they have about 1/8" of play.

not sure what you mean by play.
Does the choke plate move to full open after the engine has run for about 5 minutes?

 

[sjm32157]

Re: AFB Carter/Weber choke problem?

Replaced the filter/seperator. I'm assuming the plate opens when warm since the engine runs fine at all throttle settings. I looked for some type of adjustment on the choke linkage but couldn't find anything. This was last summer, my boat is in storage now.

 

[Don S]

Re: AFB Carter/Weber choke problem?

Nothing you can check while it's in storage. Did you check the contents of the old filter when you took it off? When was the last tuneup? Compression check, you should also check the fuel system for problems like this http://forums.iboats.com/showthread.php?t=167561

 

[sjm32157]

Re: AFB Carter/Weber choke problem?

I haven't done a tune up on the boat yet, we purchased last June. That might be worth a try before wrenching on the carb. I think my model has traditional points and condensor.

 

[Don S]

Re: AFB Carter/Weber choke problem?

I think my model has traditional points and condensor

Nope, it doesn't.
Go up to the Adults Only sticky at the top of this forum, locate and download the OEM manual for your engine and outdrive, and spend some time reading and looking around in there. Lots of info.

 

[180shabah]

Re: AFB Carter/Weber choke problem?

I have a 1995 Mercruiser 4.3 LX 205 hp with the Y43 AFB Carter/Weber 4bbl carb...or my electric choke

How much is original? A '95 4.3LX should be 175hp and no electric choke on the weber.

I have checked the front choke plates and they have about 1/8" of play...

IIRC - base setting for the choke is 5/32", although you will probably find opening it up a "hair" will be needed to keep the transom from turning black. All of the base settings and measurements are in the manuals along with tuning steps.

 

[sjm32157]

Re: AFB Carter/Weber choke problem?

Everything is original. Is the choke vacuum activated?

 

[fuzzybob]

Re: AFB Carter/Weber choke problem?

Have you downloaded the manual for your engine and outdrive??? They are free up in the "Adults Only" sticky at the top of the forum. The manual will have a great section on the weber carb.... it's the easy way to go.

My boat's a couple years older but my choke works off heat from the mani. Has a heat coil with a coil rod that moves the choke plate.

 

[180shabah]

Re: AFB Carter/Weber choke problem?

Choke on the webers has a bi-metalic spring and a vacuum pull-off, both are adjusted by bending different parts of the linkage to match the measurements in the manual.

 

[achris]

Re: AFB Carter/Weber choke problem?

How much is original? A '95 4.3LX should be 175hp and no electric choke on the weber.

IIRC - base setting for the choke is 5/32", although you will probably find opening it up a "hair" will be needed to keep the transom from turning black. All of the base settings and measurements are in the manuals along with tuning steps.

Hmm.... 1995 4.3LX should be 180 propshaft hp... These are the Gen II block (balance shaft and solid engine mounts). The 205 was the Gen I block (with fluid mounts). You're correct about the choke, the originals were 9600 models with a heat pipe. There were a lot of problems with them and in '96 they were replaced by the 9666, with an electric choke. It's very possible that he does have an electric choke as a lot of the originals were replaced.

The 5/32" measurement is for a cold choke, not the setting for a warm choke. The amount of 'play' you're seeing when the engine's warm sounds about right...

If you have an electric choke, you can check for correct operation by just turning the key to the 'ON' position and watching the choke plate. Over a period of a few minutes it should go from fully closed to fully open. The other thing those carbs do is gum up the accelerator pump. Is your spluttering as your gently accelerating? If so, that will be the problem.

Chris.......

 

[sjm32157]

Re: AFB Carter/Weber choke problem?

I dug up the manual for my power package and it is rated at 180 hp. I did download the manual for my carb and I am anxioius to give it a look/see when I get it out of storage. The engine runs great. Smooth running, good performance (20 ft cuddy, 21 inch prop, 48 -50 mph all out) reasonable fuel economy. The only dig is that is extremely "cold blooded". Thanks for all of the info. Much appreciated.