1974 Mercury 115hp flywheel rotates backwards

[jmark111]

well i have been having all sorts of issues with my 1974 mercury 115hp inline six. Well turns out that while the motor is cranking over trying to start its spinning Clockwise like its supposed to. as soon as the motor fires up the flywheel then starts turning counter clockwise. That's why my water pump spits water while cranking the engine over and doesn't spit water when it starts idling, and that is also why my gears are reversed is because the motor is running backwards!!! I greatly appreciate anyone's help i am fairly mechanically inclined but this one has stumped me for sure! I don't even know where to begin or how to stat troubleshooting this issue.

 

[jimmbo]

Interesting, as you should not have a reversed reverse, just a lot of ratcheting noise.
Is this a new-to-you engine, or did it run fine and just start doing this?
Sounds like you timing is way out. You need to check the distributor to flywheel sync. Was the distributor R&Red recently?
Bad plug wires or poor routing of them can cause the wrong plugs to fire, but I suspect the distributor is way out of sync

 

[jmark111]

well as the gear problem being reversed it has nothing to do with the lower unit and the gearing there, it engages reverse just great but since the motor is running backwards reverse actually makes me go forward. forward on the control handle is now not engaging forward or what actually would make me go backwards if that makes sense. Not an issue right now because it will all be back to normal once i get the motor to start and run the proper way. This engine has been in my possession for about 3 weeks now. i bought a project boat for very cheap that came on a trailer and with this inline six 115hp motor. long story short i hardwired the controls to the motor, replaced impeller (three times now). have done a few other minor things to the motor and now have finally realized what is happening. All plug wires from the distributor are correctly routed and going to the correct cylinders. no idea if the distributor has been R&Red recently. My first thought once i realized this issue was the motor is WAY out of timing as it was one thing i have yet to check. the strange part is this motor is a pain in the *** to start but once it fires and idles for a few seconds it idles great and runs really good, that is why i still havnt checked the timing or did the link and sync process. How do i go about checking the distributor to flywheel sync?

I appreciate the response and thank you for your time! hopefully i can get this figured out and enjoy a few days cruising around the lake before the dreaded white stuff hits the ground UHGGG!

 

[jimmbo]

Horrible pics but...
http://www.boatinfo.no/lib/mercury/manuals/mercury_1965-1989_40-115.html#/200

 

[Ibl0wstuffup]

I had a dirtbike that did the same thing, I found it had a sheared flywheel key and the flywheel was 120 degrees or so off.

 

[jmark111]

well headed to the boat now, going to look into the timing and may take the flywheel off and inspect the key. that manual is very hard to understand for me becuase i am a very hands on person and without seeing what im reading makes it hard to understand! thanks for your help. i will update this post as soon as i dig a little deeper!

 

[Faztbullet]

No key to shear.....sounds like firing order reversed in cap....

 

[jmark111]

spent a few hours at the boat yesterday and checked timing. checked out all good and did the link and sync following the video on youtube by cturboaddicts channel. everything was set up great and need very very minor adjustments. how would the firing order get reversed at the cap? all wires are in the correct place from dist cap to cylinders? should i take the cap off and clean it? scared to work on those parts with them being so fragile and so important. and most of all very pricey to replace if something went wrong!

 

[jimmbo]

Two stroke engines can run in either direction, it all comes down to the spark timing. In the late 50s Mercury introduced its Dock Buster, and engine with no neutral, just forward and reverse. It was done by starting and running the engine in both directions. The arrangement of the plug wires on the cap never changed only the direction of the rotor which of course is belt driven off the flywheel. It wouldn't hurt to look inside the cap to check condition of rotor and terminals, Just take your time and no rough handling.
After all you inspection/adjusting, does it run in the correct direction now?

 

[jmark111]

i havn't had a chance to start the motor up yet. i dont think the adjustments i made would be enough to correct the problem. everything was adjusted properly and made very very minor adjustments. im at a standstill here in my project. i have worked one many small HP outboards but nothing this big. honestly have no idea where to begin to troubleshoot this so all your help is greatly appreciated! will take the cap off the distributor and take a look inside.will i have to repeat the link and sync if i do this or can i mark the dist cap and put it baack on in the exact same position?

 

[jimmbo]

Remove the cap doesn't change any settings, but removal of the distributor will require syncing it to the crankshaft, and at the least a verification of the link-and-sync

 

[jmark111]

Well i took the distributor cap off and holy smokes it was disgusting! Cleaned it up and cleaned the points up. Also got brand new plugs just to help in starting and hopefully help the cause. New plugs never hurt. Couldnt get the boat to the water today to try it out. Muffs are my next purchase. Will keep yea posted

 

[Canufixit2]

Wait a minute ... this makes no sense. IS the starter wired backwards and it's starting the engine in the wrong direction ????

 

[ondarvr]

Wait a minute ... this makes no sense. IS the starter wired backwards and it's starting the engine in the wrong direction ????

Read his first post again.

 

[jimmbo]

If you had some crossfiring inside the distributor cap, that could have been what started the engine to reverse direction, and then it just kept running.

 

[flyingscott]

Put up a video of whats happening. Usually when the motor tries to reverse itself with a misfire it is not a subtle.

 

[jmark111]

i will try get a video, going to pick up a pair of muffs tomorrow and then hopefully get to the boat to give it a shot. i will keep you guys posted!

 

[jmark111]

well started it up on muffs and she ran great after the lync and sync and new plugs. everything worked great, water pump pumped water gears worked great. so i headed to the lake. upon putting the boat in the water it started up within 2 key turns. idled great, threw it into gear and got out from the boat launch. everything was going good until i gave it some throttle. it surged power and never even had enough power to get the boat up onto plane. surged and sounded like it was bogging out. brought it home and put it back on the muffs and it ran great! so confused but one step further ahead so thats a plus! any help is greatly appreciated and thanks for your guys time!

 

[ondarvr]

What it does or doesn't do on muffs doesn't mean much, it can sound great and still actually have all kinds of issues.

 

[jmark111]

The weird part is before i changed the spark plugs. And before i knew it was running in reverse we had it in the lake and once we got it started we took off and it had great power only i had the shifter in the reverse position but we were going forward and only for 100 feet till i relized it wasnt spitting water. Then i changed the plugs and it started right up everything was normal it idled great but upon giving it throttle it did not run good just surged a bit. Wouldnt even get up on plane. And im totally aware that motors will run on muffs but not in the lake. And to set the idle a bit higher on the muffs.