New Mercruiser Ignition sensor does not fit

kdmiller8251

Chief Petty Officer
Joined
Jun 7, 2002
Messages
495
Hello:

I have replaced my old 1990 Mercruiser 5.7 alpha I, Thunderbolt ignition sensor. They sold me new sensor but it does not fit. The mounting bolts are raised up higher and hit the rotor in the distrubtor. Has anyone run into a similiar problem?

T
 

Don S

Honorary Moderator Emeritus
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Aug 31, 2004
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62,321
Re: New Mercruiser Ignition sensor does not fit

What's the part number of the sensor you tried to put in.

It should be 87-892150Q02
 

tystick

Petty Officer 1st Class
Joined
Aug 25, 2003
Messages
278
Re: New Mercruiser Ignition sensor does not fit

I am curious....
What were the symptoms of the old sensor going bad? Did it give signs or just stop working?
 

kdmiller8251

Chief Petty Officer
Joined
Jun 7, 2002
Messages
495
Re: New Mercruiser Ignition sensor does not fit

Don:

Yes thats the part number. They screw mounting holes are raised slightly higher than the old one. Kind of strange. Have you seen that before?


T
 

Don S

Honorary Moderator Emeritus
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Messages
62,321
Re: New Mercruiser Ignition sensor does not fit

Did some checking, back when your model first came out it had 2 styles of sensors. which also took 2 different lengths of screws. There were 1" screws Merc PN 10-66686 and the 1-1/4" screws Merc PN 10-72202.
If you have the 1" screws, you can either order the longer ones or go find a couple of pan head screws of the proper size and put them in.
 

muc

"Retired" Association of Marine Technicians...
Joined
Jul 7, 2004
Messages
2,391
Re: New Mercruiser Ignition sensor does not fit

Not sure what your problem is. Your distributor should have 1 of each length screw because 1 of the screws goes thru the bottom of the distributor and has a ground wire held on with a nut. If I remember right the area on the sensor that the metal teeth of the wheel go thru is much higher than the screw heads so I would think that’s where it would hit. Might want to try a new rotor. Good Luck Muc
 

Bondo

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Staff member
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Apr 17, 2002
Messages
71,489
Re: New Mercruiser Ignition sensor does not fit

Hey Tallman,.......

Transfered Again,..??......

Looks like you're getting the Help you Need,.... Good Thing as I have No Clue...........

Good to see you again Kelvin.................d:)
 

kdmiller8251

Chief Petty Officer
Joined
Jun 7, 2002
Messages
495
Re: New Mercruiser Ignition sensor does not fit

Hey Gang! Finally made it back... Ok FINALLY got the new sensor in, looks like the rotor assemble had slid down the dist. shaft. hence the height issues.

I got it in, and am getting ready to fire it up. Thanks for the help!

T
 
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