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Removing omc out drive to check flywheel

J

Jason O Harris

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Hello all my name is Jason and

Hello all my name is Jason and from okc. I just got a 87 cheetah 20'. I have had it for two days and sunday after a long few days of fixing ods and ends it started some weird noise! I was told it was a new 4.3 merc engine. It sounds like a broken crank but it runs really good. So i need to inspect the flywheel some how? It sounds like crap and it shifts in gear good. Help.
 
Oh The knocking noise goes awa

Oh The knocking noise goes away about 1500rpm and goes away in gear. But it sounds like a broken crank but the engine runs to good. It started after we put it in the water. Thanks
 
Is this a Stringer drive or a

Is this a Stringer drive or a Cobra? It sounds like ball gears or U joints.
 
Hey Rick how do you tell the d

Hey Rick how do you tell the differents? Im new to the boat world. And i was reading down the line here that the out drive is to be down when engin is running? I had it up as i was fixing alot of loose ends. And the out drive says omc on it. Thanks
 
"I jad a similiar problem, and

"I jad a similiar problem, and 3 mechanics diagnosed it as a shot Rod bearing, and said to rebuild the bottom end. So i pulled the motor, and got it out, only to find the couping that bolts onto the crank and holds the flywheel in place was only held in by 2 hand tightened bolts and 4 really loose bolts. It made an awful racket before, sounded like rods banging around inside, but after it was tightened up, it ran like a top. Might not be the same problem, but check U joints, and make sure everything is running tight."
 
How do you pull the out drive

How do you pull the out drive off to check it? I am a mechanic but never work on out drive. Thanks Jason
 
"i'm not sure how you woul

"i'm not sure how you would do it that way. it wasnt until i got my engine right out of the boat that i realized the problem, so i came at it from the front (pull the engine forward) as opposed to pulling off the drive from the rear.
with my problem, as soon as you cranked the engine and it fired it sounded like rods were about to come flying through the block.
it sounded like yours was funning for a while then made some noises?"
 
Thanks Mark. I hope some one c

Thanks Mark. I hope some one can chime in and tell me how. Im still waiting on the board to approve me so i can post more often.
 
"If this is a Cobra drive then

"If this is a Cobra drive then it's fairly easy to remove, first you take off the nuts hodling the trim rams to the drive and push the shaft out one side, then you take off the 6 nyloc nuts holding the drive to the transom mount and slide the drive off. Be careful and try not to let the drive shaft just drop down on you (another pair of hands helps) once the shaft comes out the gimbal bearing there is nothing to support it so it drops. You should really get a manual for this and other repairs that I'm sure you'll be doing later. I'm puzzled about it being a Mercruiser engine? Also if you could find the model number of the drive on the port side maybe we can nail down the year for you."
 
Thanks Bob when i get back in

Thanks Bob when i get back in town i will look at the model number. That is how i bought the boat with a Merc 4.3 and omc cobra out drive. Im puzzled on this rod like noise in back even after i pulled the out drive out?
 
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