4.3L LX Mercruiser 4bbl carburetor issue, PLEASE HELP!

[i_timmers]

Re: 4.3L LX Mercruiser 4bbl carburetor issue, PLEASE HELP!

Does anyone think it is dangerous to blow(with an air chuck) carefully back through the pickup tube to clean out any debris that might be in there? Like I said before, am concerned about damaging the tank(poly) by attempting to remove that pickup tube? It just doesn't wanna budge... I believe I will be able to clean out any residual residue once I blow out that tube from the fuel sending unit access.

 

[i_timmers]

Re: 4.3L LX Mercruiser 4bbl carburetor issue, PLEASE HELP!

OK, Just picked up my carburetor from the shop, it's fine! The mechanic didn't even charge because he said it was clean and all jets were clear, no restrictions. Now, I have a new anti-siphon going in, a new fuel/water filter and a carb that is clean. I brought a sample of the fuel, it smelled ok in the mechanics opinion. Draining the tank is still happening and I will check the pickup tube at that time. Then there's the electric fuel pump that might have issues... What does this leave me with as far as options at this point if it doesn"t work? Electrical? The fuel was not getting into the secondary jets to fire up those barrels.

Could somebody please tell me at what point the electric fuel pump will energize during the starting procedure? I will be checking current, just don't know when to expect it to be there.

ANY IDEAS?

 

[180shabah]

Re: 4.3L LX Mercruiser 4bbl carburetor issue, PLEASE HELP!

Fuel pump gets its power from two places.

1. oil pressure switch, engine must be spinning AND key in the run position

2. the starter - energized whenever the key is in the Start position

 

[i_timmers]

Re: 4.3L LX Mercruiser 4bbl carburetor issue, PLEASE HELP!

Is it possible that the fuel pump isn't actually supplying the fuel? Reason being, When the boat was started, we pumped the throttle 2 times, it started and then died. 2 more pumps of the throttle and she started and ran until I get it up to 2400 rpm under load. Then, it leans out and won't plane. Then, at this point, when I held down the choke plate and the boat took off, running like a champ! Is is possible that the carb was able to pull from the fuel tank without the fuel pump, strictly from vacuum?

 

[i_timmers]

Re: 4.3L LX Mercruiser 4bbl carburetor issue, PLEASE HELP!

Thx 180!

I will be checking out my power into the fuel pump when I finish up with work tomorrow and I will share my results. At least I know I have power pretty much from the time the key is turned on, and until i shut it off. I sure hope I can get this figured out. Bringing anything into a shop makes me nervous and leaves you defenseless against scammers and thieves.

 

[180shabah]

Re: 4.3L LX Mercruiser 4bbl carburetor issue, PLEASE HELP!

Bringing anything into a shop makes me nervous and leaves you defenseless against scammers and thieves.

Or it could lead you to someone who is trained, factory certified, and able to isolate and fix the problem the first time.

Most mechanics are honest and dependable.

 

[Bondo]

Re: 4.3L LX Mercruiser 4bbl carburetor issue, PLEASE HELP!

Bringing anything into a shop makes me nervous and leaves you defenseless against scammers and thieves.

Ayuh,.........

Talk about Biting the hand that's Feeding ya,..........

Just who the 'ell do you think all of Us are,..??..??..??

No Brain Surgeons in here,......
But,..... There's Abunch of Mechanics...........................................

 

[i_timmers]

Re: 4.3L LX Mercruiser 4bbl carburetor issue, PLEASE HELP!

No offense was intended!

I have no referrals in the boating repair industry, and no one that can vouch for a mechanic that has done them right in the marine world. Does anyone have a boat mechanic in the Phoenix-metro area they can refer me to?

I spent 5years as a service writer, making mechanics great money. Learned alot from all of them! None of them are willing to take on a boat as a side job. They say there are tricks and methods that differ from the auto industry. Main point, they don't wanna make an expensive mistake trying to save someone some cash. For this, I don't blame them either.

This is why I have come here. There is so much experience on this site and I am learning tons just by reading the threads!

I have been thanking everyone for all their help through this process too.


Tim

 

[John_S]

Re: 4.3L LX Mercruiser 4bbl carburetor issue, PLEASE HELP!

"Does anyone have a boat mechanic in the Phoenix-metro area they can refer me to?"

I thought AZ had the largest per capita boat ownership? I do know that the lake just north-west of Phoenix (Pleasent Lake?) has some of the largest boat ramps I've seen. There has to be numerous dealers in the Phoenix area, with certified mechanics.

 

[i_timmers]

Re: 4.3L LX Mercruiser 4bbl carburetor issue, PLEASE HELP!

Lake Pleasant is closest to me, One of the boat ramps is 10 lanes and can be pretty scary on the weekends. People divebombing through there without even looking! It can be crazy... The other ramp there is 2 lanes I believe. Unfortunately, the levels are so low this season that there are some trees sticking outta the water.

If you can find me a mechanic(non dealer) in the Phoenix area that is reputable, I'm there! The closest dealer(Bayliner) in Phoenix(actually, Scottsdale)with a service center, is 30-35 miles from the house. Other dealers of other brands of boats seem to be a little reluctant about working on someone elses brand of boat(even though they have the same drives).

Convenience is somewhat important too...

 

[John_S]

Re: 4.3L LX Mercruiser 4bbl carburetor issue, PLEASE HELP!

I still had a pic of the ramp around:

 

[i_timmers]

Re: 4.3L LX Mercruiser 4bbl carburetor issue, PLEASE HELP!

WOW! That was when the lake had water in it! you can more than double (almost triple it) that ramp in length now. The water is so low. There are nothing but warning bouys out on the water, Everywhere! Great pic though... I usually park on that lower left side, that's your shortest walk to the water. It's like walking from one end of the airport terminal to another now.

 

[John_S]

Re: 4.3L LX Mercruiser 4bbl carburetor issue, PLEASE HELP!

That was from 2 years ago, this fall. Growing up in the NE, seeing a huge lake bordered by a desert was a new concept!


Anyway, lets us know when you have the carb back on and retestested.

 

[i_timmers]

Re: 4.3L LX Mercruiser 4bbl carburetor issue, PLEASE HELP!

I'm originally from Long Island myself(Coram area, Suffolk County). I kinda miss it sometimes. It's gonna be 100+ today. We are wondering if the summer is going to end this year.

Plan is to get it running and then going for a test run if time permits.


Carb is back on, new anti-siphon, fuel/water filter, fuel line to the tank, and did pull the electric fuel pump to check it's screen(it was clean). The pickup tube was clean. The fuel tank is also clean(siphoned it out last night). So, no restrictions on anything at this point. I do need to get the vacuum reading on this once I get her running, that will be a big factor.

I'll let ya know...

 

[i_timmers]

Re: 4.3L LX Mercruiser 4bbl carburetor issue, PLEASE HELP!

Well, Literally just got in from the lake! She runs like a top! It got up, and jumped to 4500+ rpms in a heartbeat! The temp stayed @ 160 and didn't rise higher either. The only thing the boat did was when I throttled back(slowly), idled the boat for 30 seconds and shut it down, it ran on for 2-3 seconds. It did this only once. Other than that, it is smoother than it has ever ran and the power didn't falter. Quick question, what's the highest rpm's that it is safe to run at? The tach shows anything above 4,500 is considered a "red zone". I figured it should be good till 5,000? Any ideas?

 

[180shabah]

Re: 4.3L LX Mercruiser 4bbl carburetor issue, PLEASE HELP!

WOT is 4400-4800RPM

 

[i_timmers]

Re: 4.3L LX Mercruiser 4bbl carburetor issue, PLEASE HELP!

Again, thanks to all for the knowledge and know-how!

 

[ksoren1779]

Re: 4.3L LX Mercruiser 4bbl carburetor issue, PLEASE HELP!

Hello

Not sure if you still visiting this site but thought I would try. I have the Year-Make-Model Capri Classic I believe. I'm not sure exactly which Carburetor I have except I know it's a 4bbl. The discussions were very interesting but I'm not very up on names/nomenclature of the carb.

My boat hasn't been started for 2-years
I had purged fuel tank before so all fuel is clean/new
New spark plugs with gap set to specifications

Problem:

Engine will start and run OK at about 1500 RPMS but will not idle. Higher the RPMS the better it runs.

I'm interested in messing with the carb but would feel better if I could find an Illustrated Parts Breakdown or I'm open to any suggestions.

The fuel tank Vent (that vents out the rear of boat) is not clogged but I don?t know if I have an anti-siphon valve or fitting.

Hopefully you still around and can get me going in the right direction

Kevin

 

[jdeeewp]

Re: 4.3L LX Mercruiser 4bbl carburetor issue, PLEASE HELP!

Ksoren, if your engine is running smooth at higher rpms I don't think you have to worry about fuel delivery to the carb,

I am no expert but it doesn't fit the logic.

i might check the timing and inspect/adjust the carb first.

 

[ksoren1779]

Re: 4.3L LX Mercruiser 4bbl carburetor issue, PLEASE HELP!

jdeeewp

Thanks. It will only stay running @ 1200-1500; it runs but not real smooth. I'm currently cleaning and lubing various carburator parts and linkages. I ran it out of gas the other day while trying to make adjustments to air/fuel so will be trying again tomorrow or Saturday.

I did find an illustrated parts break down for the carburator so hopefully that will help with that.

Any suggestion or guidance on checking the timing?

Thanks again

Kevin