Hard plane after switch from points ignition

[kbreks]

1985 mercruiser 4.3L engine. Engine is in a 1985 arrow glass carisma 188. Boat originally had a 3.8L mercruiser. Boat ran fine but the points distributor was at the end of its life. The mechanical advance was seizing and springs were shot. Advance would get stuck. Skip forward to this year. I just installed a sierra marine EST kit. Set up base timing by following the instructions that came with the kit. Set base timing to 8⁰ as per manufacturer spec. Idles amazing and runs great on plane. My issue is that it now struggles to get up on plane. Previously i had an amazing hole shot. Wouldnt even hit half throttle. 9 mph and id be off to the races. Any ideas on what may be the issue?

 

[matt167]

Delco EST utilizes less advance. You may have to bring your base timing up a little to get the performance you want

 

[alldodge]

installed a sierra marine EST kit.

You should get 20 to 22 degrees advance with the EST

Your points ignition used a full 12V feed to start and a resistance feed when running. The EST needs full 12V to start and run. Where did you get the 12V?

 

[kbreks]

You should get 20 to 22 degrees advance with the EST

Your points ignition used a full 12V feed to start and a resistance feed when running. The EST needs full 12V to start and run. Where did you get the 12V?

I ran a new wire from the ignition switch to my coil.

 

[Scott06]

I ran a new wire from the ignition switch to my coil.

What is the total timing advance you get at 2800 rpm? Would focus on matching that to what your engine had for timing curve from the factory

 

[kbreks]

What is the total timing advance you get at 2800 rpm? Would focus on matching that to what your engine had for timing curve from the factory

I will have to get a different timing light and check that. I havent been able to find much info other than what factory wants for base timing

 

[alldodge]

I will have to get a different timing light and check that. I havent been able to find much info other than what factory wants for base timing

Don't pay much attention to everything in pic except for the steps involved in setting timing. Then special attention to note 8 and seeing how much it advanced

 

[Bondo]

Previously i had an amazing hole shot.

Ayuh,..... Welcome Aboard,........ How old is the fuel, 'n the fuel filter,..??

 

[kbreks]

Ayuh,..... Welcome Aboard,........ How old is the fuel, 'n the fuel filter,..??

Both are brand new. Only started after changing the distributor.

 

[ROY WILLIAMS]

1985 mercruiser 4.3L engine. Engine is in a 1985 arrow glass carisma 188. Boat originally had a 3.8L mercruiser. Boat ran fine but the points distributor was at the end of its life. The mechanical advance was seizing and springs were shot. Advance would get stuck. Skip forward to this year. I just installed a sierra marine EST kit. Set up base timing by following the instructions that came with the kit. Set base timing to 8⁰ as per manufacturer spec. Idles amazing and runs great on plane. My issue is that it now struggles to get up on plane. Previously i had an amazing hole shot. Wouldnt even hit half throttle. 9 mph and id be off to the races. Any ideas on what may be the issue?

so the 3.8L engine 1985 or 1985 4.3L engine ?
so 1985 ignition 4- 8 BTDC timing 650-750 RPM ...

 

[cyclops222]

You MUST check the Timing Advance at several different rpm speeds. How else can you be sure the FULL ADVANCE is occurring ?

 

[matt167]

You MUST check the Timing Advance at several different rpm speeds. How else can you be sure the FULL ADVANCE is occurring ?

Delco EST does not use mechanical advance. Advance is controlled by the module

 

[cyclops222]

You can still check it with a INDUCTIVE pickup lead.

 

[kbreks]

1985 4.3l. base timing 8⁰BTDC. At 650 rpm. I will be confirming that the electronic advance is working when i get a chance to pull the boat out again.

 

[nola mike]

1985 4.3l. base timing 8⁰BTDC. At 650 rpm. I will be confirming that the electronic advance is working when i get a chance to pull the boat out again.

You can check it easily on the water.

 

[flashback]

did you replace the coil when you went electronic ignition? They are different from the std.

 

[kbreks]

did you replace the coil when you went electronic ignition? They are different from the std.

Yes i did. It came as a kit. Coil, distributor, plug wires

 

[kbreks]

You can check it easily on the water.

I meant pull it out from storage. Wont get back to the boat for a couple weeks.

 

[kbreks]

Got to checking the timing. Im guessing bad module or distributor. Only get 18⁰ total timing.

 

[kbreks]

Today i swapped out the module for an Ac delco module. Now i get 15⁰ total timing. 10⁰ base plus 5⁰ advance. At this point i am at a complete loss. Getting ready to ditch the sierra EST and find something different.