2005 Mercruiser 5.0 thunderbolt V ignition has no sparks

[achris]

which screw is used for GND or its not in this new sensor model with three wires(one wire being GND)

The black wire is ground, not one of the screws.

 

[dubs283]

that screw is not coming out

Is there by chance a nut fastened to the screw on the bottom of the distributor housing?

 

[Scott06]

Rotor is not loctited to the shaft, its just a press fit and is nasty for removal due to rust on the shaft from lack of routine tune up/maintenance.

I use the hooked jaw of a suitable sized channel lock to pry the rotor off. Clean all rust and other gunk with emery cloth. New rotor slides on great

Read attached page from manual 31 specs loctite 271 threadlocker on dist shaft and key

 

[dubs283]

Read attached page from manual 31 specs loctite 271 threadlocker on dist shaft and key

Interesting, never seen loctite remnants on the shaft nor have I ever heard of anyone applying it

 

[Scott06]

Interesting, never seen loctite remnants on the shaft nor have I ever heard of anyone applying it

Yeah makes no sense to me but u have to destroy the rotor to get it off . I changed my cap and rotor last season after six years -there was a little green corrosion on the brass contacts in the cap. what should’ve been a 10 minute job took a half an hour and required chisel …stupid

 

[lost_boys]

Is there by chance a nut fastened to the screw on the bottom of the distributor housing?

haha, just found the root of my issue...there's a nut holding a BLACK wire to that screw...on the bottom of the housing....arggggg!!!!!

removed that and with a vise, was able to remove the exposed screw....only took all day to remove this....two trips to shop to buy tools to remove stripped screw, none worked

I had to chisel the sensor our to expose the screw...do you think the hammering would do any damage to the distributor.....hope not????

 

[nola mike]

Rotor is not loctited to the shaft, its just a press fit and is nasty for removal due to rust on the shaft from lack of routine tune up/maintenance.

It is loctited...(is that a word?)

EDIT: late to the party, @Scott06 beat me to it...

 

[Scott06]

haha, just found the root of my issue...there's a nut holding a BLACK wire to that screw...on the bottom of the housing....arggggg!!!!!

removed that and with a vise, was able to remove the exposed screw....only took all day to remove this....two trips to shop to buy tools to remove stripped screw, none worked

I had to chisel the sensor our to expose the screw...do you think the hammering would do any damage to the distributor.....hope not????

No put the new sensor in and move on

 

[lost_boys]

No put the new sensor in and move on

agreed....first thing tomorrow morning...then wait for rotor

 

[dubs283]

haha, just found the root of my issue...there's a nut holding a BLACK wire to that screw...on the bottom of the housing....arggggg!!!!!

...do you think the hammering would do any damage to the distributor.....hope not????

Mercruiser tried several different methods of grounding various components of the thunderbolt system over the years. One was using the distributor housing/sensor screw as a ground, still had issues. When you install your (hopefully) oem, fully potted three wire sensor be sure to run the ground to the same stud as the main battery cable ground on the flywheel cover.

Very little chance you did any major damage to the distributor housing, they are quite stout

 

[lost_boys]

When you install your (hopefully) oem, fully potted three wire sensor be sure to run the ground to the same stud as the main battery cable ground on the flywheel cover.

of course I didn't...that would be no challenge ....arggg, the aftermarket sensor screw holes dont align up to the housing....I only bought it cause it was one day shipping....will order the OEM today

 

[lost_boys]

maybe recovering from covid is making me do crazy stuff...

yesterday, rip the old sensor apart without stepping back to understand why the screw popped loose but then locked up...

today, grinded the new sensor to align to the holes in the housing, didnt want to wait for new part....install the rotor and boat started right up...yea!!!!!

thanks everyone for helping and advice...per ur advice, grounded the wire to the GND nut where the battery is connected to...thanks again