mercruiser free revved and now quits in gear

[john demint]

Hi- In have a 1986 Four Winns with the 3.0 mercruiser 140. We were cruising across the lake when all at once, the engine free-revved... I shut it down and checked to see if the prop fell off or something! It didn't, so when I started the engine it died as soon as I put it in gear (forward or reverse). Today I drained the lower unit to see if there was any metal shavings in the gear-lube, but it is clean... ANY IDEAS??? Any help is appreciated!

 

[Bt Doctur]

Re: mercruiser free revved and now quits in gear

Exactly how much did you drain out?
Motor dies ? like it locks up,or when you try shifting into gear?
With the key in your pocket:
shift into full fwd,full throttle
have someone watch the shaft where it enters the back of the motor
have someone stand on a prop blade and try to turn it
prop moves ,shaft dosent= drive issue
prop moves, shaft moves= engine coupler

 

[john demint]

Re: mercruiser free revved and now quits in gear

I drained all the lower unit lube and it is perfect.
The motor dies like you turn the key off
When you say- have someone watch the shaft, do you mean the cable that goes from the engine to the outdrive?- Thanks

 

[Bt Doctur]

Re: mercruiser free revved and now quits in gear

Free reving means something broke. You watch the drive shaft where it goes into the back of the motor into the coupler. if the prop turns and the shaft dosent, it`s a drive problem, if the shaft does turn the coupler went bad.