2004 2.5L Carb to EFI Conversion - Knock Sensor Question

[TMANN]

Looks like I waited to long to actually make the swap and my previous thread was closed.

Good Motor - 2004 200HP Carb Serial# OT946483 Quicksilver Reman Powerhead Part#813043R00 Serial # QSJG-44820S1

Donor Motor - 2000 200HP EFI Serial# OT143783

While finishing up swapping all the EFI stuff over to the carb motor, I noticed two things about the knock sensor. The knock sensor from the EFI motor was missing. Not to mention a new one is $350ish. Also, Mercury changed the design between 2000 and 2004. The 2000 style screwed onto a head stud. The 2004 style screws into the head.

Can the 2004 style sensor be used on the earlier detonation box? Can I just do away with the knock sensor all together? Suck it up and buy the 2000 style and swap a head bolt to the 2000 style so it can be installed?

A set of cut heads and some 93 may be in this motors future.


As always Guys, Thanks for any advice!

[JOE54]

if they are same part numbers they should work , id use them on cdm ign mtrs

[TMANN]

Totally different designs. 2004 200 Head.jpeg2000 200 EFI.jpeg

[JOE54]

almost positive knock sensor does not go there does go on bolt

[EuropeanAM]

+1... that plug is there to permit the cylinder head to be used for EARLY-style (drop in hole) temp sensors OR the later-style threaded-in temp sensors (as are used with the later single-butterfly, down-draft model engines).

Knock sensor should still be on a head bolt.

[TMANN]

Thanks guys. New head stud mounted knock sensor on the way.

[TMANN]

Got it all together. Runs good on the hose at idle, but have no timing advance. Trigger tests good, 1200-1300 ohms. Any ideas? Do you guys know of a way to test the control module?

[leonreno]

I don’t know much about EFIs but do know they use a throttle position sensor that a carbed motor does not, is that installed on the new conversion and has it been tested.

[EuropeanAM]

If you have NO spark advance, make sure that the trigger is actually connected properly, shaft is set at correct length dimension, and that the trigger is advancing and retarding properly.

[TMANN]

That's correct Don. Zero spark advance. The trigger coils test good per the manual. The stem is adjusted correctly. I can grab the linkage with the engine running and see the timing retard. I have another trigger here from the donor motor I will try. The donor motor has a brand new stator and trigger installed so it lead me to believe I was chasing the previous owners ghosts.

TPS has been tested. Made a small adjustment to fine tune.

The control module was replaced. No change.

[TMANN]

Could the detonation module cause zero spark advance?

[EuropeanAM]

It could retard the timing- unlikely it is causing ZERO advance, though. ADI ignition it's a separate device and can be removed (completely). Not so easy with CDM ignition (which utilizes an ignition module).