83 50 hp merc bogs and cuts out at higher rpms

[Marshman]

Hi all<br /> Im new to these forums but hopefully I can provide enough info to get an answer on my problem.<br /><br /> I run my my boat for 2-3 minutes it will turn about 4000 rpms tops (which I dont think is right either) then it will start to bog and rev a little and bog and rev. Then I will try to go full throttle again it wont let me will bog again. The olny way to move is slow 3000 rpms max or it will bog?? Im stumped I've changed lots of parts this year.<br /> 1 new carbs gaskets and fuel pump diaframs<br /> 2 all new fuel lines inside the engine area<br /> 3 new plugs<br /> 4 new CDI box last year<br /><br /> When I take the plugs out after running it they are fouled im pretty sure.<br /> I have adjusted the low speed screws on the carbs as per my manual. Set to idle at 900 rpms. I have 2 carbs are they supposed to be adjusted differently? One richer or leaner? If I try to lean it out at all it wont idle. I am stumped any help in this matter would be greatly accepted.<br /><br /> THX. Marshman

 

[12Footer]

Re: 83 50 hp merc bogs and cuts out at higher rpms

If you're pretty confident in the werk you have allready done, I would re-inspect the spark at the plugs. These 4 cylinder mercs will run (poorly, but will run) on 2 cylinders.<br />I think you'll find a bad trigger,switchbox,or fouled plug or two. Triggers seem to be the most frequernt failure (from what I have seen) on these motors. The switchboxes are not bulletproof, but as long as it has good connections, good insulation, is kept relatively dry and the engine does not overheat, they hold-up better than most.

 

[Marshman]

Re: 83 50 hp merc bogs and cuts out at higher rpms

THX 12footer<br />I was curious if you or anyone know a way of testing the trigger or the switch box? <br /><br /> Thanks again<br />Marshman

 

[Marshman]

Re: 83 50 hp merc bogs and cuts out at higher rpms

Anyone else have any ideas any input is greatful!!<br /><br />Thx Marshman

 

[Marshman]

Re: 83 50 hp merc bogs and cuts out at higher rpms

Bump