1985 90hp regulator/rect. effects?

[captain catfish]

i have ordered a new reg/rect, but it wont be here until tuesday. i am replacing it because it doesnt seem to be charging the battery(the battery never shows voltage over 12.6 running or not) we took the boat out today and at wot the max speed was 17 (normally its around 24) we have had the boat out a few times and it ran great prior to today, but the battery had been charged (start of the summer/ 1st outing of the boat this yr), the battery still shows 12.6, but could it actually not be providing enough power to the motor with a bad reg/rect?


im sorry if that is to confusing.
thanks
mark

 

[Fed]

Battery charging & ignition are completely separate systems.

 

[boobie]

Agree with the above. Sounds like you have two separate problems. What rpm does the motor turn up to ??

 

[captain catfish]

[FONT=Calibri, sans-serif]well I cant say what rpm, because the tach will not function properly due to the reg not working. what I can say is the highest I ever saw on the tach was around 2400 but that was with it jumping all over the place, all I can tell you is speed (gps), I've been fighting this problem for a yr or so now, that's why I bought a tach for it, but that has shown me the regulator problem. I hope after I get it changed I can further investigate the problem. this is a pontoon boat and all we do is ride out to a slew and swim or chill out. I have had it out 2 times this yr and it did great, but that was on a fresh charge each time. when we brought it home yesterday I didn't do anything to it, just parked it and took it back today, it never ran correctly. [/FONT]
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[FONT=Calibri, sans-serif]I have, been through both carbs, several times (kits each time), several new plug changes( various brands), new fuel pump (deleting the oil injection) , hoses, hoses/ primer bulbs, cleaned the fuel tank and added another clear filter to see any trash headed to the fuel pump (its staying clean). [/FONT]
[FONT=Calibri, sans-serif] [/FONT]
[FONT=Calibri, sans-serif]when all is right with the stars and planets, it will run 24mph, when its having problems it runs 17, just like clock work. I have check the link and sync, the timing, and the spark.[/FONT]
[FONT=Calibri, sans-serif] [/FONT]
[FONT=Calibri, sans-serif]the only thing I have not changed is the reg because I never knew it was bad until I installed the tach.[/FONT]
[FONT=Calibri, sans-serif] [/FONT]
[FONT=Calibri, sans-serif]so any suggestions would be greatly appreciated. I have rebuilt cars/trucks/motorcycles/gocarts/ and feel really comfortable working on anything with an gas burning engine. but this thing is kicking my tail. [/FONT]
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[FONT=Calibri, sans-serif]the problem is so intermittent .[/FONT]
[FONT=Calibri, sans-serif] [/FONT]
[FONT=Calibri, sans-serif]thanks[/FONT]

 

[emdsapmgr]

Erratic tach reading are typically a sign of a failing rectifier/regulator. This charging system is separate from the ignition side of the engine's electrical system. The fact that the boat voltage never goes above normal battery voltage is also a sign of problems with charging. You did not say just what engine you have. Many of the OMC's only use the battery for starting and for operating the trim. (obviously also for the lights, radio, bilge pumps, etc.) Once the engine starts, it runs off it's own internal voltage-battery not required. Years ago, before battery chargers on engines, an owner could use a starting battery for months on a single charge. Only recharged the battery every month or two. But back in those days, the engines were 25 to 40 hp only. Did not take much juice to turn those starters for 15 seconds...

 

[captain catfish]

there are no tags/model #s on the motor anymore.
it is a 1985 90hp evinrude. ihope to install the new reg today and maybe test it on the water tonight or tomorrow depending on weather.

 

[emdsapmgr]

There is a casting plug on the top of the block. I has the same serial/model information that the transom bracket tag has/had. Check it out. Here is a picture of what one looks like. Yours will be painted over, so look carefully. This tag is for a 1975 , electric start, long shaft 135 hp engine.

 

[captain catfish]

thanks for all the input, today/tonight i changed the reg, now i have 13.9 volts at idle, also i found the Trigger base linkage had fallen off, its not as secure in its base (i'm talking about the arm with a ball that attaches into a socket just under the flywheel) as i think it should be, i used a zip tie and some small floral wire to help secure it until i can find out if the piece is replaceable. the motor sounds different than it did before, started very easily and idled a lot more smoot than it ever has. i hope i can put it on the water tomorrow. also the tach is dead steady with no twitching at all.

i will update after a test on the water.
thanks again for all the input.
Mark

 

[captain catfish]

i was really hopeful i had fixed this thing, i have fixed the charging and the tach problem. i took the boat out this morning and it ran great (1st time since the reg/rect change) . i only ran it about 15 min because of the weather. we took it out again tonight and ran it for a good 30 mins, and everything was perfect, best its ever run. until we stopped in a slew for about 30 min, when we went to leave it was obvious that something wasnt right, we could only turn 3000 rpms vs the 4200 we were turning prior to stopping.

i didnt have any test equip on the water with me, but when we got home, i check for spark (while running) some little hand held test that lights up, i have spark at each cyl. but when i pull the plug wire from 3 cylinders i get a reaction, but on the 4th nothing, i hooked up a spark test tool, and have a good spark, i didnt set it to 7/16s probably a 1/4 judging by eye, but it does have spark, i swapped leads from the power pack with cylinder above (the lower right is the problem) and plug wires, but the problem didnt follow the "coil" so i did a compression test and both cylinders were 116 and 120.

pulling the plug wire off the bottom right cylinder does nothing to motor, each of the others will have a noticeable impact on the idle, but not this 1 cylinder? someone please help me.

thanks
mark