OMC Charging

[caiman]

After following the micro genset thread,it has just occured to me,is there an easy way of boosting the charging output of my 1988ish Evinrude 8hp Sailmaster outboard?Different coils maybe?Re magnetise the flywheel?The engine is standard as far as I know,and the charging system is working,although I don't know at what ampege.I am using a 105 A/H battery.
Also,can anyone point me towards a 'high thrust' prop please?(9 1/4x6 1/2 part number 0392183)
Cheers

 

[VicS]

First the model and the year.
Sailmaster was the Johnson name, Evinrudes were called Yachtwin I think you will find

You can determine the year from the model number

The Evinrude will be E8SRLCCS, the Johnson J8SRLCCS where CC are the date letters for 1988 but you can determine the year if not '88 from the code INTRODUCES code where I=1, N=2, etc to E=9 and S=0 ( so CU = '87, CE =' 89 ES = '90 )
The final suffix letter will be different but has no significance

There is no alternative charging coil listed..
That one was fitted from 1985 to 1988 and a completely different flywheel/ignition and charging system was fitted in 1989/90 and changed yet again in 1991/2.

I am not sure of the maximum outputs. The 1984 version was only 4 amps. The later ones may have been 6 amps but no more.

You will only get anything like the max current at fairly high revs and for a small sailing boat in which you run the engine for the minimum time the total amount of charging you get is so pathetically small that its is best ignored and a solar panel or wind generator used instead.

The 9¼ x 6½ high thrust prop fitted to both the 6 and the 8hp Sailmasters and Yachtwins is no longer available ... so take care of the one you have!

 

[caiman]

Hi VicS
You are right it is a Johnson.The engine number is J8SRLCRM.I think I've figured that J Johnson 8hp rope start long shaft,but am lost on the CRM bit.I'm not certain of the year but I think it's 88ish.
You are right again about the low use on a sailing boat not charging the battery adequately,and this is my problem.
Has anyone fitted non standard coils to this engine to boost the charging rate?
Wind power is out,and I've had limited success with the longevity of the 'cheapo' type solar panels.The cheap panels must work though, since I frequently could smell 'battery gas' on initialy opening the boat.
I've settled for a cheap two stroke gen set for the time being(I certainly cannot afford a £600 jobbie) purely for battery charging.It just seems daft carrying two engines to do the same job.I used the outboard to charge the battery a bit this morning,at low revs it was acceptably quiet but as you say,the output is low also.I used the gen set this afternoon,not really any quieter,and without an ammeter,I'm not really sure what charge is going into the battery.
Can you tell me the reccomended NGK plug please?
I agree with the 'Vote of Thanks',I've read some of the very helpfull replies that you have given to lots of people,Nice One Dude.
Cheers

 

[VicS]

CRM makes it a 1984 model The same age as my 6hp Yachtwin.


C = 8 and R = 4 hence '84 . As explained above in the "INTRODUCES" code

"M" s just a production suffix without significance

Evinrude and Johnson only recommend Champion plugs to which end the currently recommended plugs are QL77JC4, or QL86C which are slightly hotter.

The Q indicates inductive suppression so if you do not need interference suppression L77JC4 or L86C would be acceptable

The currently recommended gap is 0.030" ( 0.7 - 0.8 mm), originally 0.040" (Use which ever works best if there is anything to choose)

The nearest NGK equivalents are BZ7HS-10 (or B7HS-10 if you do not want the inductively suppressed "Z" one). You can ignore the -10 as that indicates that the plug is supplied ready gapped at 1 mm (0.040")

DO NOT use NGK "R" series plugs they are resistor plugs and will give poor performance with the OMC CD ignition system . If you are offered BR7HS go elsewhere! **

For what it is worth I find no difference between the original Champions ( they were QL77J4 back then) and NGK B7HS or between 0.030" and 0.040" gap.

If you can find any higher output coils then please let us know but remember that the rectifier is only rated at 6 amps and is non regulated. The big engines with much more powerful stator coils also use a water cooled rectifier/regulator.

I have a small, 5 watt, Spectra solar panel that is adequate for my needs. Original recently replaced with this one from Seateach. If I had room I'd fit a 10 watt one probably.


** Full technical explanation of the need for low impedance inductive suppression at http://members.iinet.net.au/~pauldawson/iame26-spark-plugs.PDF


BTW any cooling problems... look at the grommet at the top of the water tube. Check that you get good flow through it whenever you replace the impeller. In fact you might as well replace it at the same time!
PITA as it needs the powerhead to be removed to get at it. Modified mine... time will tell!

 

[Stu Jackson]

Vic's spark plug recommendations are right on. That's what we use on our 1990 Evinrude, no alternator. No difference in performace between brands, I use the regular ones, not the noise suppression ones 'cuz the engine's for my dinghy.

The use of small outboards to provide adequate battery charging is truly a joke. A solar panel, and depending on your house bank size, a regulator, is the most appropriate way to go. Find a quality solar panel and it'll last a lot longer than the el cheapos you've been used to.

What batteries really need? Download the ample Power Primer, tech tab, here: www.amplepower.com

Your batteries and your pocketbook, will thank you.

 

[caiman]

Thank you gentlemen for the info about the plugs,and about the water tube grommet.
It looks like solar is going to be the way to go,backed up by the genset.
I toyed with the idea of an alternater driven by belt from the flywheel on the outboard,but I havn't seen any alternaters that small.
Now I've seen it again,INTRODUCES makes sense to me!!-Cool.
Thanks for your help so far.
Cheers