85 hp seahorse v4 problem

[nate1220]

Hi all, I am working on a 1979 seahorse 85 hp v4. The problem is when you throttle the engine up it drops two cylinders then when you idle it down they kick back in, The guy who owns it has changed the coils and the cdi boxes, I have gone throught the fuel system and still no luck. the only thing I can think of is the stator. Also all 4 cylinders have good compression. Please help thanks.

 

[nate1220]

Re: 85 hp seahorse v4 problem

Should I pull the flywheel and see how things look?

 

[jimdd810]

Re: 85 hp seahorse v4 problem

First pull the plugs how do they look? I think your high speed orifeces are plugged on one side so i would pull the carbs and do a good cleaning on both of them

 

[emdsapmgr]

Re: 85 hp seahorse v4 problem

Check the stator.

 

[nate1220]

Re: 85 hp seahorse v4 problem

I pulled the flywheel today and the stator is brand new, all the wires are good no breaks in them and I have good spark at idle, put it back together fired it up after cleaning every single electrical connection on the motor and same thing idles great but throttle it up and it drops 2 cylinders on the same side, I rebuilt the carbs last night and now they are spotless, anymore ideas.

 

[Daviet]

Re: 85 hp seahorse v4 problem

When you say throttle up, do mean on muffs or in the water under load? You can use an inductive timing light and check for spark when the problem occours, will tell you if your problem is fuel or electrical.

 

[nate1220]

Re: 85 hp seahorse v4 problem

on muffs

 

[Daviet]

Re: 85 hp seahorse v4 problem

What is the rpm when you loose the cylinders? Have you tried backing the boat in the water and run up the engine under load, leaving it on the trailer?

 

[nate1220]

Re: 85 hp seahorse v4 problem

I haven't tried it under load but the guy that owns it says it does the same thing under load, it looses the cylinders about 300 to 400 rpms off idle

 

[emdsapmgr]

Re: 85 hp seahorse v4 problem

It almost sounds like some wiring moves to ground when the throttle linkage moves. The timer base is something that moves with the throttle movement. Check it's wiring and be sure none of the wires are grounding to the block as the timer base moves. You can also remove the link arm to the timer base and leave it in one position, then throttle the carb separately to see if it will take throttle while the timer base does not move.

 

[nate1220]

Re: 85 hp seahorse v4 problem

thanks I will try that. I have been racking my brain.I took all the wiring off the motor and checked it all for breaks or burnt wires and the whole wiring harness is in perfect condition. I will have to disconnect the timing linkage and try it. Thanks again.

 

[emdsapmgr]

Re: 85 hp seahorse v4 problem

You could have an open in one of the wires from the constant movement of the timer base.

 

[nate1220]

Re: 85 hp seahorse v4 problem

I will have to look again but I checked all the wires like a surgeon. I have been working on outboards for about 5 years and have learned my lesson about let's say "not using a fine toothed comb"

 

[emdsapmgr]

Re: 85 hp seahorse v4 problem

What stator voltage outputs are you seeing? In the 150 volt range?

 

[nate1220]

Re: 85 hp seahorse v4 problem

I took the linkage for the timing advance off and the motor throttled right up without a problem all four cylinders ran great so I hooked the linkage back up and adjusted the linkages so that the butterflies on the carbs open up more before the timing starts to advance and now it seems to run really good. was this the right thing to do?

 

[emdsapmgr]

Re: 85 hp seahorse v4 problem

The factory service manual describes the sync and link procedure. This procedure is the adjustment of the relationship of the spark advance to the opening of the carb butterflys. It does require a specific relationship for optimal operation. You may find it runs even better if you follow the manual as you do the adjustment.

 

[tashasdaddy]

Re: 85 hp seahorse v4 problem

you have 2 power packs. one for each bank of cylinders. swap the power packs. then see if the problem follows the park to the opposite side.

 

[nate1220]

Re: 85 hp seahorse v4 problem

it has four coils and two cdi boxes which are all brand new and I have swapped them from side to side and the problem stayed in the sme place.