Mercury 90 FOURSTROKE Lubrication Fitting

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
richiemac
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Mercury 90 FOURSTROKE Lubrication Fitting

Postby richiemac » Sat Jun 03, 2023 6:04 pm

The lubrication fitting which goes into the vertical case by the shift rod on a 2015 Mercury 90-HP FOURSTROKE engine does not accept grease. I have removed the fitting and checked with a pump. I think [problem is a result of\ the lubrication channel being plugged.

Give advice.

ASIDE: the engine is on a 2015 170 MONTAUK that is stored in a garage. When the engine has 200-hours of run time and was serviced, the fitting accepted greats. Crease came out from both upper and lower ends. The engine now has 300-hours run time.

jimh
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Re: Mercury 90 FOURSTROKE Lubrication Fitting

Postby jimh » Sun Jun 04, 2023 6:03 am

I think you are describing the grease fittings or zerk fittings which are intended to permit grease to be pumped into the tiller tube of the engine. If you cannot pump grease into that area, the old grease may have hardened. A possible remedy is to use a hot air blower to apply heat to the tiller tube to warm the grease inside so it becomes more soft. New grease being added should then be able to push out the old grease.

Jefecinco
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Re: Mercury 90 FOURSTROKE Lubrication Fitting

Postby Jefecinco » Sun Jun 04, 2023 10:27 am

You may also try applying pressure with a grease gun attached to the zerk fitting while a helper moves the steering fully left to right and back several times. If this fails apply heat as suggested by jimh.
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Phil T
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Re: Mercury 90 FOURSTROKE Lubrication Fitting

Postby Phil T » Sun Jun 04, 2023 11:17 am

If the above does not work, replace the zirk fitting in the tube.
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fno
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Re: Mercury 90 FOURSTROKE Lubrication Fitting

Postby fno » Fri Jun 09, 2023 9:04 am

Or the check ball in the Zerk is corroded and stuck to the fitting. Tap on the ball with an awl or scriber and a small hammer to free. If the above works or doesn't replace the Zerk fitting. Be advised that the fittings available at an auto parts store will be zinc plated and as such a temporary fix. If you never want to have this problem again, get 316 stainless Zerks from McMaster-Carr. (yes, I am an ardent pitch man for McMaster)