Mercury 800 thunderbolt issues

[Alimuhassen]

Hi guys this is my first post, so bare with me. I have a mercury 800 thunderbolt, it' starts right up and sounds great. I recently bought the boat, the first time me and my girlfriends dad took it out, he decided to be a smart *** and lower the motor before he backed up in the water. The prop and lower unit fin hit the ground and got chipped pretty badly. It makes a grinding noise when its in reverse, prop still spins, just not as fast as it should be. So is this issue related to the prop hitting the ground?
And the Motor also dies in full throttle when its in the water. I'm thinking it's probably carb or fuel pump?

Any help would be greatly appreciated, thanks.

 

[Alimuhassen]

Re: Mercury 800 thunderbolt issues

Anyone? I need to fix this thing.

 

[ShowMeGuy]

Re: Mercury 800 thunderbolt issues

Dying at WOT sounds like the carbs need cleaned... the grinding due to it hitting the ground? Who knows... Time to get dirty it sounds like to me.

 

[mr 88]

Re: Mercury 800 thunderbolt issues

If the prop is banged up it's time to get it fixed or replaced.Unbalanced prop= prop shaft seal/carrier bearing blowing out and a vibration carried throughout the engine. Agree with the carbs being rebuilt.

 

[Alimuhassen]

Re: Mercury 800 thunderbolt issues

Thanks for the input guys. I started taking the carbs out. And i just rebuild the fuel pump, hope that cures my WOT issue. And I'm getting a new prop. Before I go out on the water again. Any ideas why its grinding in reverse? I mean, when I bought the boat, I put it in reverse and it was perfect?

 

[mr 88]

Re: Mercury 800 thunderbolt issues

Check your linkage on the motor,it may need adjustment as it sounds like it is not fully engaging.If it is still grinding then it's exploring time in the gear case.

 

[Alimuhassen]

Re: Mercury 800 thunderbolt issues

Ok so I checked the shift cable, and adjusted it as far as I can, and the prop spun better now and less grinding, but now forward is not fully engaging? I'll check the gear case, maybe the linkage in there is not connected right?