1997 mercuiser 5.7 running real bad need HELP.!!!

[jws123]

1997 mercuiser 5.7 2barrel mercarb spring needle NOn vortex sent carb out to be rebuilt cause boat was stalling at idle all the time and lack of power now it wont run right blows black smoke hard to start ect ect i did intake seals due to a leak so now i am looking for the timing settings for the thunderbolt ignition and the correct float settings. All spark plugs wires cap rotor coil ect where changed it just wont run right i am at a loss.

 

[alldodge]

It was stalling and now after rebuild it has black smoke, won't run right and hard to start. Sounds like the carb rebuilder messed (flooding) up and needs to be redone correctly.

Have you checked compression?

 

[jws123]

It was stalling and now after rebuild it has black smoke, won't run right and hard to start. Sounds like the carb rebuilder messed (flooding) up and needs to be redone correctly.

Have you checked compression?

Yea compression is good i already took carb back twice now i took it apart its a simple carb but i need float settings the timing was also messed with

 

[alldodge]

Timing set at 8 BTDC and place distributer in base timing mode. Base timing is set by connecting the Purple/White wire coming from the ignition module to ground

 

[jws123]

Timing set at 8 BTDC and place distributer in base timing mode. Base timing is set by connecting the Purple/White wire coming from the ignition module to ground

Ty il make sure its set right later just need float settings tried looking in my manual but it sucks.

 

[alldodge]

I think you should have a weber carb and if so the float should be between 1/4 and 3/8, more to the 3/8 side but not all the way there.

 

[jws123]

I think you should have a weber carb and if so the float should be between 1/4 and 3/8, more to the 3/8 side but not all the way there.

Its a mercruiser 2 barrel carburetor i thought about throwing the whole 2barrel and intake out and goin 4barrel but dont have the money rn

 

[jws123]

this is the carb i have y-381 https://goo.gl/PQohJX

 

[alldodge]

Here is how to rebuild and adjust
http://www.boatfix.com/merc/Servmanl/18/18B5R2.PDF

 

[jws123]

Just went to check timing and i noticed i do not have numbers on timing chain cover Only a mark on balancer and 1 mark on plastic cover how do they expect people to set timing?

 

[alldodge]

Take some sand paper to the damper, get timing tape or need a advance timing light

 

[jws123]

Take some sand paper to the damper, get timing tape or need a advance timing light

ok thanks

 

[jws123]

OK timing set float set the dam thing is still running terrible black smoke hard to start runs good when warmed up if i turn it off let it sit few mins same thing hard to start have to full throttle it to start black smoke checked compression its good now its down to fuel pump even tho its new... i am getting about 6-7psi whats normal for a 2barrel? i have heard of people using regulators but not sure what one i would need or is there a better pump i should be using??? i am at a loss lol if i had the money i would go 4barrel asap just want to get the boat running factory.

 

[alldodge]

Your symptoms still show its getting to much gas. This is caused by choke, needle seat not closing fuel off or float level to high. Fuel pressure should be between 4-7 psi so your good. Changing to a 4 barrel just adds more barrels, it will not change your issues if it is not functioning correctly. The black smoke indicates its getting to much fuel

The Merc 2 barrel does have a needle seat issue and is identified in a bulletin. There is two needle valves can be used, one with a spring and one without.
http://www.marinemechanic.com/merc/distributors/mercurymarine/sterndrive/mercarb.pdf

 

[jws123]

Your symptoms still show its getting to much gas. This is caused by choke, needle seat not closing fuel off or float level to high. Fuel pressure should be between 4-7 psi so your good. Changing to a 4 barrel just adds more barrels, it will not change your issues if it is not functioning correctly. The black smoke indicates its getting to much fuel

The Merc 2 barrel does have a needle seat issue and is identified in a bulletin. There is two needle valves can be used, one with a spring and one without.
http://www.marinemechanic.com/merc/d...ve/mercarb.pdf

Yea i have taken this carb apart 100 times lol i switched from spring to solid needle then re set float to make sure that wasnt the issue i even took carb to a place i am ready to drop the whole fkin boat off at this point.... i am a mechanic and this one is driving me nutz makes no sense. its ether running to rich or my ignition system is fked up and letting it flood at first witch is rare for a thunderbolt ignition i have heard.

 

[alldodge]

Wonder if the check ball and spring are sealing off the pump discharge area like they should. Its for the accelerator pump, but if the check balls are not sealing off, the fuel could be coming in. If it was this piece you should see fuel drip when the motor is on and even off maybe. Don't see the issue being the ignition, it wouldn't cause black smoke

 

[jws123]

Ok messed with this thing for 5 hours today found the problem (profanity will not be tolerated, mis-spelled or otherwise) Ok so i get the thing running after a few mins of trying to start once running and warm runs great if u shut of off then fire it right back up runs good . HOW EVER if you let the boat sit a few mins for some reason it builds up a bunch of pressure in the fuel line???????????? tested this by cracking open fuel line right after i shut it off not much pressure but if i let it sit for like 10-20 mins the gas comes flying out i assume this is my flooding issue what the heck can cause this??? i checked the fuel tank vent and left cap off.....

 

[alldodge]

Pressure build up after running can come from heat. The pump should have its own pressure relief valve and should bleed off the excess pressure. You could install a secondary regulator to control this. Is this a Sierra pump? Reason for asking is their quality control is not worth using. You can get a good one, or otherwise

https://www.summitracing.com/parts/...lD4lBCy8vlZCRzC-NLdpMLtkCYfenOvRoCjmAQAvD_BwE

 

[jws123]

Pressure build up after running can come from heat. The pump should have its own pressure relief valve and should bleed off the excess pressure. You could install a secondary regulator to control this. Is this a Sierra pump? Reason for asking is their quality control is not worth using. You can get a good one, or otherwise

https://www.summitracing.com/parts/h...RoCjmAQAvD_BwE

Its a GLM pump whats a good brand to use? im going to get a new pump also going to get that regulator most likely

 

[alldodge]

You shouldn't need the regulator if you have a good pump. I don't think much of GLM either, but instead of getting another pump, just get the regulator. I use Aittex or Merc, Airtex makes the pumps for Merc but I also use BBC pumps

Another thought, do you have the spacer installed (item 5) between the pump and block?
http://www.mercruiserparts.com/bam/subassembly/31865/2344/60