This product has been discontinued.
Sierra
Sierra Merc Engine Coupler - 18-2175 - Sierra
Price: $327.94
Discontinued
Part # 18-2175
(Discontinued)
This item is found in the following Product Families
Replaces OEM part #
  • MERCURY MARINE 18643A7
For: Mercruiser Flex plate style, late model, small crankshaft bolt pattern style engines.
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Coupler
by Shane from North Billerica, Massachusetts on September 11, 2017
I am looking for the bolt pattern separation 1.750 between each other for it to fit on my rebuilt 1975 350 5.7 liter OMC chevy engine. The new engine has a bigger 6 bolt pattern than the engine that was in the boat and I bought a new fly wheel that fits but the old fly wheel and coupler won't fit the new engine so I am seeking the search for a new coupler to fit this application.
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awesome
by Kevin from Spencerport, New York on June 02, 2015
perfect fit now i can keep the coupler and splines greased
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Perfect
by Robert from Kimberly, Idaho on July 03, 2014
Excellent product and value. iBoats service is outstanding.
(1 of 1 people found this review helpful)
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coupler
by Robert from Kimberly, Idaho on June 12, 2014
Excellent value and service.
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Coupler Upgrade
by Robert from Haw River, North Carolina on August 02, 2013
...now I can grease the slip joint without removing the drive....perfect fit,arrived "the" day promised...and we are back on the water !!
(1 of 2 people found this review helpful)
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Q:
It's the bolt spread 1.750 apart from each other with a 2.500 center ?
A:
Manufacturer confirms they do not go off bolt pattern on the couplers. They match it by application because it meets OE specifications.


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