Mercruiser 260 lost power to prop

[germaneighter]

It has been about 20 years since my last boat, ('74 16' Glatron w 140 Mercruiser) New boat is a '84 Chris Craft 21' Scorpion w a 260 Mercruiser. I've had the boat out about 3-4 times without any problems. Yesterday while pulling my wife on a ski about 28 mph, I lost power to the prop. The motor reved-up but the boat stopped. Looked at instuments and water temp was about 200. (I think it usually runs around 140) I killed the motor and let it cool down to 160. Motor fired right up but when I push throtle forward or backward, nothing happens. No sounds at all. Also, the engine temp climbed quickly to 180.<br /><br />Earlier in the day we had churned up some mud with the prop while trying to leave from a shallow area. It was a low speed thing and I was not too worried. The boat ran well afterward. <br /><br />It seems like I have an overheating problem and some type of drive coupling problem.<br /><br />Is there an easy test to isolate the drive issue?<br />Any advice or suggestions?<br /><br />Thanks in advance.

 

[achris]

Re: Mercruiser 260 lost power to prop

Sounds like you snapped a driveshaft or chewed up the gears in the top box. <br /><br />To test. Put it in forward gear and see if there is a ratcheting noise when you turn the prop clockwise. If not, you have a 'disconnection' in the line somewhere. At the same time see if you can turn the prop counter-clockwise. It should be 'locked' by the engine. Make sure the key is 'off' when you do that. Better still, put the keys in your pocket!<br /><br />The other thing I would do is to remove the top cover on the top of the leg and have a look at the gear teeth. Remember to re-torque the screws to 20ft. lb. when you replace the cover.<br /><br />Chris........

 

[outboardguy]

Re: Mercruiser 260 lost power to prop

Sounds like you either spun the engine coupler or the gears in the upper are gone.I would start by pulling the vent plug in the port side of the upper drive( it has a slot for a flathead screwdriver)if metallic oil comes out, you probably blew up the upper.Then you can remove the top cap to confirm. If oil is clean it is most likely engine coupler.Put shifter in fwd gear and then remove drive by removing rams, then remove six nuts and pull drive free. Look at the driveshaft for the condition of the splines then look into the bell housing and check the condition of the coupler splines. Let us know what you find.<br />In edit Chris kinda beat me to the post

 

[achris]

Re: Mercruiser 260 lost power to prop

OBG,<br /><br />If it was a spun prop, it wouldn't be overheating....

 

[outboardguy]

Re: Mercruiser 260 lost power to prop

Chris did I say anything about a spun prop????? <br />I believe I only talked about the Engine coupler and the Upper gears as you did.

 

[achris]

Re: Mercruiser 260 lost power to prop

OBG,<br /><br />Sorry, right again. Read it too quickly. Please don't beat me.......<br /><br />Chris.............

 

[germaneighter]

Re: Mercruiser 260 lost power to prop

Chris/Outboardguy,<br />Did the tests that you mentioned. In gear, rotating the prop clockwise produces a strong ratcheting sound. At first try, I could not rotate counter-clockwise. Then I applied a little more pressure and could rotate CCW but it was tough. I pulled the small top cover and it appears that the gear on the shaft going towards the motor in "skinned clean". When I rotate prop CCW the veticle shaft spins but no movement on the horiz shaft. I can see this would cause the drive problem. Does it also contribute to overheat issue? Is this a tough repair? Ballpark cost to have it done? Cost to do myself? What are the major points of the repair?<br /><br />Thanks for your help.<br /><br />dave in Tulsa

 

[flashback]

Re: Mercruiser 260 lost power to prop

Germaneighter, yes, the situation you described would certainly cause the engine to overheat.. looks like it might be time to try one of those new drives advertised here on the forum. I believe it would be less expensive than rebuilding the one you have.......

 

[achris]

Re: Mercruiser 260 lost power to prop

Germaneighter,<br /><br />Sorry to hear the bad news. To rebuild yourself requires a few special tools and unless you plan on doing quite a few, it's not economical.<br /><br />Chris............

 

[germaneighter]

Re: Mercruiser 260 lost power to prop

Can you tell what ratio outdrive you have if you count the gears at the top of the outdrive? drive gear is 20 tooth and driven gear is 22 tooth.<br /><br />thanks,<br />dlg

 

[codyandamber]

Re: Mercruiser 260 lost power to prop

After you find out exactly what you have check Ebay. They are much cheaper than anything you will find in a marine shop. If you only need the upper you might be able to find one for as cheap as $250 with shipping. Of course, they are used for the most part. Anywhere else and you are looking close to $1000 for a rebuilt. They have them on this site.

 

[Bondo]

Re: Mercruiser 260 lost power to prop

Your drive ratio is 1.5/1..............