Mercury 1976 (1150) Runs Backward

[EBAUGHMAN]

New to this site guys. Been down since 4th of july, checkmate died on river. Thought it was impeller and replaced it... fancy myself a shade tree boat mechanic but always I/Os.... not these old outboards. Engine starts, slows down and bucks then the crank-flywheel starts running counterclockwise. Summer in Pa is short enough..any help to get me back on the Allegheny River??? many thanks.. Erock

 

[daveswaves]

Re: Mercury 1976 (1150) Runs Backward

New to this site guys. Been down since 4th of july, checkmate died on river. Thought it was impeller and replaced it... fancy myself a shade tree boat mechanic but always I/Os.... not these old outboards. Engine starts, slows down and bucks then the crank-flywheel starts running counterclockwise. Summer in Pa is short enough..any help to get me back on the Allegheny River??? many thanks.. Erock

The engine should not be capable of actually running backwards unless the timing was waaaay off. It can lean sneeze and kick backwards CCW but should not stay running backwards. The older dockbusters, which did run either way, had a special distributor that allowed the engine to run backwards.

What happened when it died on the 4th of July, symptoms, how was it running before it died?

 

[EBAUGHMAN]

Re: Mercury 1976 (1150) Runs Backward

Dave..thank you for responding. Merc was running good, I was pulling grandkid on a tube, sudden shut down. Restarted but with throttle wide open only got about 700 rpm. If I pulled back to neutrel to get into forward gear merc stalled..got towed in to dock. Pulled out of water and with water boot restarted..no water cooling...thought heat had expanded pistons and impeller was suspect. Installed impeller and no water took lower down again thinking water tube was not installed in correct position..(did this 5 times). Finally pulled top hat cowl off and I saw what was happening, starter driving it one way and then occasionaly starting but not much..then slow and buck and take off counterclockwise at a great rate,that pretty much takes the fuel system out of the troubleshooting. I stopped it quickly because of no water. Timing belt is intact, cleaned cap, filed rotor. Got a junk motor of same year and style in my garage bought for 50 dollars...but dont know where to go from here. I checked TDC on #1 good...Could timing belt have jumped a tooth??? Fuel screen is clean. Thanks.. Erock...Where you from??

 

[daveswaves]

Re: Mercury 1976 (1150) Runs Backward

Dave..thank you for responding. Merc was running good, I was pulling grandkid on a tube, sudden shut down. Restarted but with throttle wide open only got about 700 rpm. If I pulled back to neutrel to get into forward gear merc stalled..got towed in to dock. Pulled out of water and with water boot restarted..no water cooling...thought heat had expanded pistons and impeller was suspect. Installed impeller and no water took lower down again thinking water tube was not installed in correct position..(did this 5 times). Finally pulled top hat cowl off and I saw what was happening, starter driving it one way and then occasionaly starting but not much..then slow and buck and take off counterclockwise at a great rate,that pretty much takes the fuel system out of the troubleshooting. I stopped it quickly because of no water. Timing belt is intact, cleaned cap, filed rotor. Got a junk motor of same year and style in my garage bought for 50 dollars...but dont know where to go from here. I checked TDC on #1 good...Could timing belt have jumped a tooth??? Fuel screen is clean. Thanks.. Erock...Where you from??

Thanks for the info, based on the mode of failure I suspect the timing belt has jumped a tooth, likely 2. The toothed pulley on the distributor could be worn or the belt worn to allow the jump. If you have a manual, even a seloc, it will walk you through aligning the distributor marks on the distributor gear with the mark or marks on the flywheel. If not I will try and post a procedure for you.

I'm up in Ontario Canada, Lake Erie.

 

[EBAUGHMAN]

Re: Mercury 1976 (1150) Runs Backward

Your too kind.... thank you.. gotta place to start anyway. Regular wheel puller get that fly wheel off?? If the rotor is in the proper position related to tdc gotta be somthing else..right? But does spark advance come into play in relation to position?? Erock

 

[daveswaves]

Re: Mercury 1976 (1150) Runs Backward

Your too kind.... thank you.. gotta place to start anyway. Regular wheel puller get that fly wheel off?? If the rotor is in the proper position related to tdc gotta be somthing else..right? But does spark advance come into play in relation to position?? Erock

A regular puller will take the fly wheel off, just remove 3 of the centre bolts to line up with your puller. Merc has a special puller that screws into the center of the flywheel that works much better, but I have pulled quite a few with a standard puller. Don,t forget the flywheel nut! I would not go by the position of the rotor as it will change depending where the throttle is. There is a dot on the top of the distributor that lines up with a dot or dots on the flywheel when the pointer is set to the .454 mark on the flywheel. The dot will be slightly off alignment, either side of the ring gear tooth that the dot is above. I suspect that if you line up the pointer with the .454 mark on the decal you will find the dots quite a bit out of alignment.

 

[EBAUGHMAN]

Re: Mercury 1976 (1150) Runs Backward

Thanks..Get back to camp this week and see what I can do. Just got laid off so lotta time on my hands. Terrible times..half my street laid off. Send you a bottle if this plays out. Erock

 

[daveswaves]

Re: Mercury 1976 (1150) Runs Backward

Thanks..Get back to camp this week and see what I can do. Just got laid off so lotta time on my hands. Terrible times..half my street laid off. Send you a bottle if this plays out. Erock

No need for a bottle, thats what this board is for, helping other boaters out. Heck you are almost my neighbor, just a little lake in between. I can see Erie PA at night. Nice fireworks on the 4th.

 

[EBAUGHMAN]

Re: Mercury 1976 (1150) Runs Backward

Good advice Daveswaves, was many teeth out. First attempt though, engine ran at 2000rpm... regret messin with the dist stops. 3 times later and i think i found right tooth, good idle at 750. Hard starting cold.... this morning before i left camp.. though... might be cause i am mixed much too rich,when its warm just touch the key and it comes to life, what do you call for 40/1?? River too high from rains to put in water for testing.. also thru week nobody around to pull you in if trouble comes. My father, up in years, called me last night at camp and asked me if i fixed it...told him a guy in Canada fixed it..he is not part of computer age and said what the h are you talking about... Send me that mix ratio if you would.. thanks. Erock

 

[Chris1956]

Re: Mercury 1976 (1150) Runs Backward

50::1 is the correct gas-oil ratio.

Are you sure you have it timed correctly? At TDC the cast pointer on the distributor pully should point at dot on flywheel. Is the timing belt good?

Idle pickup timing should be 4-6 degrees BTDC. Max spark advance should be 21 degrees BTDC.

 

[EBAUGHMAN]

Re: Mercury 1976 (1150) Runs Backward

Thanks Chris,
Going to pump out tank and refill with 50/1. as for btdc..over my head, belt in good condition, had to pry up with screwdriver on dist to change position. My kids and myself run it hard..... everybody wants to go full throttle, fun and flipable boat....worries we with my kids, very shallow draft,you can touch the water from drivers seat, cant understand how it jumped time. Dropping it back into river Sat going to put some belt dressing on belt see if it sticks and prevents jump.