Serial number not correlating. What timing to use? Choke on power wire?

[lr3guyjoe]

I just got done installing a sniper efi on my 3.0l.

Want to double triple check I have the timing dialed in. According to the book there are one of three to use. The trouble is I can figure out what my serial number translates to. It M023026 and that is nothing like the ranges listed.

Also I read somewhere here that there should be an inline choke on the power wire going from the coil to the distubtror. My wire has been cut and spliced at some point an there is nothing inline on the wire. Does there need to be?

Timing will be when placed in base timing mode

1-BTDC for serial number 0L096999 and below
1-ATDC for serial number 0L097000 - 0L0340999
2-ATDC for serial number 0L341000 and above.

Plugs MR43LTS

Advance

• If initial timing is 1° BTDC: 12° BTDC, plus or minus 2°. At 2400-2800 rpm maximum
(total) advance is obtained and should be 23° BTDC (plus or minus 2°).

• If initial timing is 1° ATDC: 14° BTDC, plus or minus 2°. At 2400-2800 rpm maximum
(total) advance is obtained and should be 25° BTDC (plus or minus 2°).

• If initial timing is 2° ATDC: 15° BTDC, plus or minus 2°. At 2400-2800 rpm maximum
(total) advance is obtained and should be 26° BTDC (plus or minus 2°).

 

[jimmbo]

First Things first. Is that Sniper EFI, USCG approved, or is it an Automotive Unit?

 

[Fun Times]

Your serial number (0M) is above the serial number 0L341000 as 0M is a newer engine model vs the 0L. 0M should be about 2001ish or a bit higher in year model. 0L is an bit older model... late 90's roughly.

This mentioned, if still in place and legible, the black plastic cover over the top of the engine/carburetor should have a sticker with some engine specifications on it and should mention the OEM timing specifications.

An example,

 

[Fun Times]

Wire harness item number 19 would have the diode type component inline of the wire.

EST IGNITION COMPONENTS - 1996 Stern Drive 3.0LX [ALPHA] 430L000JS | Crowley Marine

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www.crowleymarine.com

 

[lr3guyjoe]

Thanks gents. The flame arrestor is still there but looks like it arrested a big flame at some point in its life and the sticker is cooked.

I ordered a nos #19 wire harness.

Per Holley: United States Coast Guard Approved Certified to ISO 8846, SAE J1171 Requirements

 

[lr3guyjoe]

Lastly is the module (77-8M6008208) in the distributor Mercruiser specific? Or will just a quality GM replacement suffice?

 

[Scott Danforth]

good luck with your sniper.

 

[Scott06]

I just got done installing a sniper efi on my 3.0l.

Want to double triple check I have the timing dialed in. According to the book there are one of three to use. The trouble is I can figure out what my serial number translates to. It M023026 and that is nothing like the ranges listed.

Also I read somewhere here that there should be an inline choke on the power wire going from the coil to the distubtror. My wire has been cut and spliced at some point an there is nothing inline on the wire. Does there need to be?

Timing will be when placed in base timing mode

1-BTDC for serial number 0L096999 and below
1-ATDC for serial number 0L097000 - 0L0340999
2-ATDC for serial number 0L341000 and above.

Plugs MR43LTS

Advance

• If initial timing is 1° BTDC: 12° BTDC, plus or minus 2°. At 2400-2800 rpm maximum
(total) advance is obtained and should be 23° BTDC (plus or minus 2°).

• If initial timing is 1° ATDC: 14° BTDC, plus or minus 2°. At 2400-2800 rpm maximum
(total) advance is obtained and should be 25° BTDC (plus or minus 2°).

• If initial timing is 2° ATDC: 15° BTDC, plus or minus 2°. At 2400-2800 rpm maximum
(total) advance is obtained and should be 26° BTDC (plus or minus 2°).

What do you mean by inline choke in coil to distributor wire? Never heard of inline choke…do you mean the shift interrupt?