85' 90 hp inline 6 spark problem!!

[ryanalaska1990]

okay.
i changed the recifier first. it started up and ran good. then i let the motor sit over night and came out and nothing.... so i replace the stator, ran great for about 5 days then i left it sitting for 3 days and the no spark agian... so i just got a used trigger online and replaced that. it fired right up. ran great all day. then it sat overnight last night. i came out and tryed to start it. it was having trouble as it always does the first start of the day but it was trying to fire. then the battery cabels got really hot and the battery died. i took the battery off and charged it up. and then tried it agian and now im back to having no spark at all in any cycilder agian! rectifier is still powered up.

so does anyone know what happened here? or what the problem may be. i have put in plenty of money in this boat and i really wanna keep it and use it more then a week at a time!
im at the end of my rope!
thanks agian
-Ryan

 

[ryanalaska1990]

Re: 85' 90 hp inline 6 spark problem!!

i also replaced one of the switch boxes and the starter solinoid.

 

[j_martin]

Re: 85' 90 hp inline 6 spark problem!!

Cables hot is a clue. When the starter nears end of life, current draw typically goes way up, and RPM goes down.

Check you starter motor current with a hold it against the wire amp gauge. Should be around 125 amps.

Proper diagnostics is the fastest and least expensive route to a repair. Throwing parts at it is generally the slowest and most expensive.

 

[ryanalaska1990]

Re: 85' 90 hp inline 6 spark problem!!

the starter is definitly on its last legs. but would that cause it to loose spark? i just ordered a new starter. when it was firing(had spark) the starter would kick out 3-5 times before it finally started up.

 

[ryanalaska1990]

Re: 85' 90 hp inline 6 spark problem!!

can a bad starter make a trigger go bad? anyone have any ideas on whats going on here. new starter is in the mail .

thanks agian
-Ryan

 

[Cogburn]

Re: 85' 90 hp inline 6 spark problem!!

Firing of the switchbox is dependent on the trigger voltage.

If cranking speed is low then the trigger voltage will be low because it's signal voltage is generated by magnets in the hub rotating by it.

If the trigger voltage is too low the switchbox won't fire the coils.

Viola-no spark...because of a bad starter,bad connections,low battery,etc.(or more specifically low cranking speed).

 

[ryanalaska1990]

Re: 85' 90 hp inline 6 spark problem!!

that makes me feel a little bit better that a may just be the starter and i wont have to replace the trigger...agian.. however. sence the battery connections were getting roasted, could i have fried my trigger?

thank agian everyone any help is GREATLY appricated!

 

[Cogburn]

Re: 85' 90 hp inline 6 spark problem!!

The battery should have no connection to the ignition system. The ignition system doesn't need the battery to make spark other than to turn the engine over.

The only connections that even come close are the black/yellow kill wire that is grounded through the ignition switch to shut down the engine(which should never have any voltage on it in any switch position) and the red wire which connects to the rectifier output for charging the battery.

Therefore; the connections at the battery should not do anything to the trigger as the trigger should only be connected to the switchbox inputs.

 

[ryanalaska1990]

Re: 85' 90 hp inline 6 spark problem!!

ok i found and fixed the problem. itwas the mercury switch. the switch that kills then engine when its tilted past a certin point. now. its running but the idle is really high. i tryed lowering it using the screw but it didnt change anything

any ideas on how to lower the idle??? once the idle is down then im finished and its good to go!

-Ryan

 

[j_martin]

Re: 85' 90 hp inline 6 spark problem!!

ok i found and fixed the problem. itwas the mercury switch. the switch that kills then engine when its tilted past a certin point. now. its running but the idle is really high. i tryed lowering it using the screw but it didnt change anything

any ideas on how to lower the idle??? once the idle is down then im finished and its good to go!

-Ryan

I suspect that after messing with it for weeks without knowledge, you may have it pretty well fuddled up.

No problem. Get the factory manual. In that manual is a linkage and timing adjustment procedure. Once that is properly performed, it's just set the idle speed, and maybe idle mix to perfect running.

Without the preliminary link and sync setup, all other adjustments are a crap shoot.

hope it helps
John

 

[Cogburn]

Re: 85' 90 hp inline 6 spark problem!!

The idle is actually controlled by the timing.

The carbs should be shut at around 3? btdc timing. That will probably get a high idle and is called the primary pickup point(when the throttle is advanced there is a cam that "picks up" the throttle arms) .

Idle speed is lowered from that point by retarding the timing and is set by turning the lower bolt stop on the big vertical throttle arm and adjusting the throttle cable to put a slight tension on the lower stop bolt while in neutral.

The upper bolt in the big throttle arm is the throttle stop which is there to prevent breaking the throttle linkage and stops on the carbs.

There are two screws to the left and above the top carb and the outer on controls the max timing, the inner screw controls the throttle primary pickup point.

There is a description of how to do a link and sync both here...

http://forums.iboats.com/showthread.php?t=128495&highlight=link+sync

http://forums.iboats.com/showthread.php?t=168855

Getting the motor properly timed and synced is extremely important as these engines do not like being improperly timed and will burn pistons if not correctly set up.

 

[vnvet72]

Re: 85' 90 hp inline 6 spark problem!!

Does anyone know the amp rating of the stator and is it capable of running a tachometer ? 1986 L6 90Hp. I'm rewiring the whole boat 17'Montauk, new accessories, dual batteries etc..

Thanks for any help.

 

[Chris1956]

Re: 85' 90 hp inline 6 spark problem!!

Those stators were no more than 12A. They can run any std marine tachometer.

 

[vnvet72]

Re: 85' 90 hp inline 6 spark problem!!

Moved to new thread "ELECTRICAL"