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Help, honda bf90a issue

H

hairdresser100

Contributing Member
I have a boat with twin 1997 Honda BF90A carburated Hondas and need help on what seamed like a simple issue. Turning over fast.

When I bought this boat last year it had 3 batteries in it and the stb motor always seamed to have a dead battery. I would charge the batteries and the stb motor would always have just enough cranking power to get it going in the morning ........once warm, it would be fine all day no matter how long I stopped.[FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]
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[FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]After watching the very short charge time on the charger, I realized the batteries were not dead. I had them tested and they were ok. Not great but not dead.


So, I replaced the batteries with two (changed from a 3 battery system to a 2battery system) new large batteries and the same thing happened so it wasn't battery related. This past winter I rewired everything the right way sparing no expense. Everything new. I figured I got it....NOT! Same engine turns over real slow on battery one or two then comes to a stop on the 3rd-4th crank. Switch to both batteries so two batteries are now running the starter and again, it sounds like I could have just enough to start it. Batteries and wiring not my issue.


The other motor always turns over very fast, no issues there.[FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]
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[FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]I have a parts motor and swapped the started....same thing..slow turn then it stops quickly about the 3rd crank. Does the same on battery 2. Other engine on battery 1 or 2 turn like a champ.[/FONT]
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[FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]I wired it correctly, batteries are strong............what would cause the motor to act like a dead battery all the time?? Internal engine parts, magnetic starter switch...... I should pull one spark plug out at a time and check the rate of spin to see if one of the cylinders makes a big difference.[/FONT]
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[FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]Last year I did get in a jam where the two charged batteries were not good enough and the motor stopped after 8 turns and was dead. I thought the motor was seizing up so I used a huge screwdriver to rotate the flywheel a little bit from what I assume was the compression stroke, then the starter was able to get a head start and spin past the next compression stroke and start.[/FONT]
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[FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]Any clues? The Honda manual didn't really help.[/FONT]
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[FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]No fuses blow.[/FONT]
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[FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]I do have one bad kill switch. Pull the lanyard off and it still runs. Not sure if that's port or stb though.[/FONT]
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[FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]I did a compression test on both motors and got 90 psi in all 8 cylinders. Should be 215 so I assumed by gauge was bad....if not it should spin even faster!!! [/FONT]
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[FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]THANKS!!![/FONT]

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After better understanding the magnetic starter switch that can't be the issue because it's doing its job, engage and tell the starter to rotate.
 
Most common cause of a problem like this is a bad battery cable to the engine. Could have deteriorated inside and does not allow enough current through to crank the engine.

Since you have a spare engine. Grab the battery cables from that engine and put them on the problem engine. You do not even have to take off the old one. Having two battery cables to the same battery will cut down the voltage drop and probably get you cranking.

Mike
 
I would certainly try what Mike suggests but, if that doesn't do the trick, I just wanted to say to you that it could indeed still be the magnetic switch. Much like the breaking down of the battery cable's ability to deliver AMPS, as Mike relates, the magnetic start solenoid is also tasked to deliver AMPS to the starter and can fail in delivering ENOUGH amps to properly crank the engine if it starts to break down too.

There is much info on the inner webulator about VOLTAGE DROP TESTING of these high amp components and it is pretty easy to find a good tutorial on how to do your own troubleshooting using this method. It is easy to do and will ABSOLUTELY aid you in PINPOINTING the offending components if done properly.

Many times, these types of problems are the result of MORE THAN ONE component OR CONNECTION being at fault and the VOLTAGE DROP method of troubleshooting your starting system will help you find ALL OF THEM.

Good luck.
 
Hi Guys!

Thanks for the info. As far as the pos and neg factory honda cables I will dig deeper and you bring up a great point that makes me 100% believe the owner was working on this issue. When I rewired the boat the previous owner had an extra battery and ran two #4 positive cables from the batteries to the on/off switches.

I reterminated both "boat ends" of the honda pos and neg cables and they looked great. Good quality stranded copper but that doesn't mean they're not broken at some high flex point. The "engine side" of the pos and neg looked crimped and soldered. I'll do that tonight. I have some extra #2 cable left over. These issues are usually on the ground side of things.

OK, I did read all about testing the mag switch last night so it does have something to do with this...interesting. When I was bench testing the old starter I learned about the switch. I'll swap switched from port to starboard and see if that's it. (My parts motor didn't have the magnetic switch or I would have swapped in already. I saw it was $70)

I'll also get a torque wrench and see if it takes the same amount of force to rotate the port vs the starboard to rule out a mechanical issues.

When I removed the starter from my motor and looked down the hole at the ring gear, all was clean and factory fresh...NOT like my parts motor. Glad for that!
 
Electromagnetic solenoid switches are relatively simple. Inside there is a contact disk and point device. After numerous starts the disk and point get burned, increase in resistance and reduce current flow thru the contact. Your only recourse is to replace them periodically as a preventative maintenance item to keep the starter healthy. If yours has two top studs just short them together to see if the starter flys...if it does you have solved the problem. They come apart very easily for inspection...take a look if you replace it.
 
"Good quality stranded copper but that doesn't mean they're not broken at some high flex point. The "engine side" of the pos and neg looked crimped and soldered"

A battery cable does not need to be "broken" to have it lose it's ability to carry current. Surface corrosion of the multiple stranded wires that make up a "0", "OO", "OOO" or four ought cable can increase resistance enough to cause the cable to have a significant "VOLTAGE DROP". This term is for the amount of power the cable is "robbing" instead of "delivering" as it should.

I keep pounding on this term and it's related testing technique using a simple, easy to use, inexpensive to purchase device, a DVOM because it will tell you EXACTLY what is being lost and where.

And, the world will be a better place when everyone knows how to do it:)
 
What a night! I have good news and during my celebration dance I was shocked!

Hondadude, you done it again! I placed a battery on a ladder near the engine and ran some #2 pos and neg cables to the starter and she turned over like it should have, fast! The problem was someone cut the pos cable in half, used some home thin metal connection that was cracked and broken, electrical taped it up then shoved it so far under the starter I could never see it. Amazing......and to think I never got stuck out there or the cable didn't short to the engine block.

Then during my celebration high / victory dance I did something just as stupid as who ever pieced this cable back together. I broke the #1 rule which is disconnect the negative cable from the battery first!!! I put the wrench on the positive starter cable nut and swung the wrench right into the regulator/rectifier sending sparks flying and ending my celebration high. Think I fried anything?

HondaDude/ jgmo does this site compensate you for your time? If not I'd send you a couple bucks for sure.
 
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guyjg, excellent point and I'm all for maintenance and hands on work. I'm going through this boat from bow to stern and things are looking up.

jgmo, you are 100% correct and I kind of screwed that point up. After finding this bad connection that was way low in the engine and at times in salt water, I cut the insulation back by 2 feet and the cable was still black and full of salt and absolutely junk. It was 100% not like the nice shiney/clean end I cut a day or two ago. It's all in the trash now!! More #4 coming tomorrow.

The bad thing is all salt water boats are full of these nasty cables and we don't even know it until something fails.

Love the site, way more polite and professional than The Hull Truth!!!
 
Glad you found the problem. You probably did not fry anything. The outside of the reg/rect is grounded, so most likely you just shorted the positive to ground for an instant.

Easy check...turn the key switch to on and is what the voltmeter on your dash reads. When you start the engine, the voltage should increase, generally to about 13 or 14 v when you run at high rpm.

Mike
 
Hairdresser100,
Really glad you solved your mystery. Too bad you didn't get to do it with VOLTAGE DROP testing but, hey, maybe next time?
I agree with Mike, you just did a bit of arc welding with the wrench and more likely than not you did no harm to anything except the wrench and your victory dance!
Thanks for the kind words and, after watching Mike save SO MANY boaters SO MUCH money since I've been on the forum, I will definitely kick in a few $$ if you get a hondadude "vacation in the Bahamas" fund started:)
 
Thanks guys!

I was hoping that was the case with my sparking of the regulator and thought for once Faraday's law would be on my side. Also, because of its location, I'm sure I'm not the only one who's made that mistake but it didn't seam to be a hot topic anywhere.

You guys should set up an address for "donations" for your good work. Thanks again for your help!!

I'll look into a DVOM meter today because I'm always working on things.

And lastly for people reading this in the future. After I untangled and pulled the bad cable out of the motor one could easily tell a huge difference in the cable's flexibility which means "it's under suspicion" and look at it more closely. The cable was 7' long and 4' of it was junk.
 
hairdresser100,

Just send lots of money to my paypal [email protected].

Only kidding of course.

Thanks for the kukos but this forum is a group effort to help each other. No one person knows it all. I know, I also make a living at fixing things, but I consider this a way to keep my mind active (as I get older) and a way to pay it forward.

I probably learn as much as you guys do. There is thousands and thousands of years of experience ready to help. You just have to put up with the times, we send you down the wrong path. We are not always right.

Mike
 
Hay guys, you were right. Zapping that regulator with the positive starter cable didn't hurt my charging system. I started them up today and that motor charged at 14 volts....thank God!
 
Well, I imagine that all I have to say would be very similar to what you had to say and that is..................



YIPPEEEEE!

and

WHEW!
 
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