1996 454 thunderb ign thompson wont get on plane

[Mattsbuoy]

Thank you for assistance. Used boat starts great idles great slow operation around 1100 in now wake is great. Will not get up on plane. Fresh gas and oil change and arrester cleaned and fuel sep changed. Going to do cap rotor wires and plugs tonight. Is there an electrical diag to confirm plug ins?
Not a mechanic but can do basics and know mechanics. Thank you

 

[Eric 3.7LX Alpha 1]

Thank you for assistance. Used boat starts great idles great slow operation around 1100 in now wake is great. Will not get up on plane. Fresh gas and oil change and arrester cleaned and fuel sep changed. Going to do cap rotor wires and plugs tonight. Is there an electrical diag to confirm plug ins?
Not a mechanic but can do basics and know mechanics. Thank you

Was that added to last years stale gas, or no old gas at all, tank was empty?

 

[Mattsbuoy]

Treated 1/2 tank old gas with proper seafood amount due to fiberglass tank in thompson. First run it wouldn't go up on plane either so I went to marina and filled up tank.
More seafoam? To retreat the old gas?
Thank u

 

[alldodge]

What's your serial number?

 

[Mattsbuoy]

Engine or boat? If ur asking engine I need to know where to look please and thank u.

 

[Rick Stephens]

If old gas is bad,, no amount of Seafoam dreamer's solution will fix it.

All it takes is a little crap in the carburetor and again, no amount of mechanic in a can is gonna get the passageways back open. Only a carburetor rebuild will do that.

 

[Mattsbuoy]

Great input. Thank you.

 

[alldodge]

Engine or boat? If ur asking engine I need to know where to look please and thank u.

Engine
Look for a plate above the starter on the side of the block

 

[Bondo]

Engine or boat? If ur asking engine I need to know where to look please and thank u.

Ayuh,...... Welcome Aboard,....... In this forum, We don't care what yer boat is,......'
We Gotta know what yer motor, 'n drive are,......

 

[Scott Danforth]

More seafoam? To retreat the old gas?
Thank u

you cant unmake bad gas. once gas turns to varnish, your only choice is to pump it out, pay to dispose of it, clean the whole fuel system and then start over with fresh gas

 

[Mattsbuoy]

Ayuh,...... Welcome Aboard,....... In this forum, We don't care what yer boat is,......'
We Gotta know what yer motor, 'n drive are,......

1996 mercruiser bravo with thunderbolt ignition. I cannot read the serial number as single screw its buried deep. Owner had nothing

 

[Mattsbuoy]

Engine
Look for a plate above the starter on the side of the block

Cannot read plate. Single screw so engine is deep in hull. Will try to gwt it at tune up. Owner had nothing. I have boat hull number.... can I search that way? Thank u everyone. I live on no wake but still I want to be able to shoot across the lake sometimes.

 

[Scott Danforth]

Carb or efi?

Smooth valve covers or ribbed? (gen 5 or gen 6 identification)

6 bolt or 10 bolt timing cover (gen 5 or gen 6 identification)

Fuel pressure?

Compression numbers?

 

[alldodge]

Does it have a carb, EFI, TBI or MPI?

 

[Mattsbuoy]

Carb. Smooth valve covers. Will look at timing cover when in there doing tune up. .035 gap on Delco plugs?
Will do compressions at tune up also. Thank u
Not sure about pressure other than idle and startup and 1500 and below are flawless fyi.

 

[Scott Danforth]

smooth valve covers means you have a 1991-1995 gen V motor (the 1996-2000 came originally with ribbed valve covers)

you can confirm as the timing cover should have 10 bolts vs the 6 on the 1996-2000 gen 6 motors

what is your fuel pressure? should be between 3 and 5 psi

 

[Mattsbuoy]

Thank you will have to test that

 

[Mattsbuoy]

Good plug but........ need to find wire for this sensor. Urgh. Where does it come from? Thabk ypu

 

[alldodge]

Tan wire goes to water temp gauge

 

[Mattsbuoy]

Distributor only using 1 socket. If looking at the engine from drivers seat socket on left is empty. Guessing this thing is a crazy girlfriend candidate.