Honda BF115A will not start

2004 Honda BF115A ran good two weeks ago. This weekend tried to start and starter worked, motor turned over but will not start. Battery good, battery cables to engine good (new connectors), voltage 12.7 v with ignition switch on. When ignition switch turned to start voltage drops to 9.6 v. No fuel getting to cylinders, cannot hear fuel pump running when ignition switch first turned on. Fuel pump connector has 12.6v for 2 seconds after ignition switch turned on. No spark to spark plugs when engine turning over. Power relay removed and tested good. All fuses tested good. Control cable continuity test good. Something causing voltage drop when ignition switch turned to start. Fuel flow to vapor separator good. Could faulty fuel pump cause voltage to drop when trying to start but not when ignition switch turned on? Don't have MIL indicator lights on boat so have not tried ECM diagnostics. At wits end! Any ideas?

Do you get two beeps and do your two lights come on for two seconds when you turn the key switch to on?

The voltage drop at the starter is caused by the current draw of the the starter causing a voltage drop in the battery cables. If you are measuring the voltage at the battery, then there may be problems with the battery.

If you can not hear the fuel pump when the key turns to on but you are getting voltage to the connector.....jumper 12 v directly to the fuel pump. That will give you an opportunity to listen when all else is quite. If you do not hear the pump, reverse the leads and see if you can jar it loose (it could be frozen for one reason or the other).

Drain the vapor separator into a glass jar and see what the fuel looks like.

You say there is no spark, but the spark is very hard to see on these motors.

Check that fuel pump first and let's see what you find, before jumping to other things.

Mike

Thanks for reply Hondadude.
Got two beeps and two lights for two seconds. Very little voltage drop at battery, voltage drop at starter solenoid seems too much. Rd somewhere that Honda motor will not start with volage below 10.6v. Tried two batteries, both tested good.
Used jumper in parallel with starter cables and got voltage drop to 10.5v. but would not fire up.
Drained some gas from vapor separator, looked and smelled Ok.
Will reversing voltage on fuel pump hurt pump?
Could ECM need resetting?
Thanks,
Jack
























`123456790-=QWRTY
IOP[]ASDGHJKL;ZXC
VBM,.
start

Have you checked your ground cable to make sure you have a good ground?

Reversing polarity on fuel pump is ok. It is a DC motor, it will run both ways.

Mike

Could be the fuel pump problem, you can test it easy,give direct 12v to pump connector and see.if fuel pump is good you should hear the sound,when you turn on the ignition SW.

But you mentioned no spark at the plugs. even cant you see little spark on the plugs ?

First make sure the fuel pump,


wajira

Thanks Mike, will check fuel pump tonight. My hearing is getting bad along with eyesight but that happens with old age. Might try to use a stethoscope on fuel pump. This fuel pump is mounted in canister beside vapor separator and not below as on some older models. I guess it will be loud enough to hear.

Thanks wajira, will try tonight and see what happens.

Something else came to mind. Dirt daubers had built two nests under timing belt cover.One nest was next to balancer belt tensioner and other nest was next to timingbelt driven pulley. All seemed to turn freely with nest intact. Removed nestand vacuumed out loose dirt. No visible damage to components but could this have done any damage to alternator?

Can't say for sure that there was no spark at spark plugs. Had neighbor looking for spark as I cranked. He's old like me so he might not have seen spark even if there was one.

Thanks for reply Skooter. Ran #4 welding cables parallel to battery cables and connected directly to engine ground and + terminal on starter solenoid. With cables in parallel voltage drop was 10.5v when trying to start but motor would not fire up. My first thoughs were bad battery, bad cables or bad connectors. Have pretty much tested and ruled those out. Batteries load tested and tested good, a little over charged. Had that problem with an older carbureted Honda 90 a while back and new connections fixed the problem. Not so lucky with this 115.

Another question. Malfunction Indicator Light connector. Everything I see in the wiring diagrams shows a three pin MIL connector with Yel/Blk, Wht/Blu and Red/Blu wires. I can only find a six pin connector on the motor right next to the 14 pin main control connector. This six pin connector has Yel/Blk, Wht/Blu, Red/Blu, Blk and Light Green wires going to it. I don't have an MIL so nothing is connected to this connector. Is this six pin connector the MIL connector on this motor and I assume the black wire is ground, but what is the light green wire?

Yes it is the mil connector. The mil lights only use the y/b, w/b and r/b leads. The other two leads are for ground and fuel pulse lead for the old Honda digital gauges.

You should be able to hear the motor with just holding a screwdriver against the fuel pump housing and the other end up to your ear. A stethoscope should work fine too.

As for not seeing spark. The spark on these things is very small and hard to see.

Since you said you had mud dobbers in the engine....the nest may have caused the timing belt to jump time. You will have to remove the timing belt cover to check the timing marks.

I would not bother with that unless you hear the fuel pump running.


Mike

Fuel pump not working. Connected it directly to battery, forward and reverse polarity, used stethoscope, no noise at all. Measured resistance across winding and it read 2.2 ohms. Not sure what it should read. Guess that means a new fuel pump, no new shoes for the kids this winter. Would this have caused voltage drop or is that kind of voltage drop normal when starting? Is there anything in particular that would cause the pump to fail?

dirty fuel,water in a fuel can badly stuck the fuel pump motor.
.the pump should work with direct battery supply, open pump and see you can find the problem easily for sure.

Thanks wajira! Will take out fuel pump tonight and see if it may be something that can be fixed internally. Hate to buy a new pump if I don't have to.

You probably already have taken it apart....but when you do check the connections to the motor inside the container. They may just be corroded. Pull the connectors off and apply 12v directly to the two contacts on the pump.

Try not to jar the pump while checking.....

I say that, because that is the next thing to try....

If the pump still does not run, try tapping it on a firm surface while the 12v is applied to the pump.

If there is gooed up fuel, you might be able to soak the pump in some brake clean or sea foam for a little while (do not use carb cleaner) then try the test again. Try reversing polarity several times.

If it is just gooed up and you are able to get it running, it may likely continue to run ok.

If there is evidence of corrosion or water, just buy a new pump....Even if you get it going, it will stop again....probably...when you are at the farthest distance from your home port.

If things look bad there, you should also take your vapor separator apart and check that out. It probably needs a good cleaning too.

If in any case you boat on anything more than a small lake, it will be best to just buy a pump.

You are probably talking $250 - $300 for all the necessary parts and seals. Cheap insurance...especially if your wife is on board when it goes out.

Mike

Thanks hondadude! Had storm last night so didn't get to remove fuel pump. Placed order for new one with new o-rings, etc., not sure I'd trust this one again and wife is allergic to paddles, she gets red in the face and very vocal at mention of the word.
Based on your experience is that voltage drop to 9.6v normal at starter solenoid when starting or do I need to do more checking?
Thanks,
Jack

I would not be too concerned with the voltage drop at this time. The minimum service limit, per the manual, is 7.5v cranking under load. There may be something going on there, but you have found one major "known" in your puzzel. Fix that problem and the others may work themselves out....if there are problems.

Just like eating an elephant.....you do it one bite at a time.

Mike

Hello Mike: It was the high pressure fuel pump. Finally got the new one in and installed and it started right up and ran great. Took the old one and tapped on it with a small hammer, tried to blow it out with the compressor and hooked it up to battery, forward and reverse. Never could get it to run. There was no trash in pump cannister and filter was not in bad shape. It would draw a spark on the leads and jump slightly but would not rotate. Almost like something was jammed inside. I understand that it is rare for these pumps to go bad but it makes me a little shy about taking this thing very far out. The old carbureted motor might spit and sputter every so often but never just shut down completely.
Thanks for you help!

Glad things worked out. I understand about the fuel pump reliability. It is 10 years old. I do not know if you are the original owner....if not....who knows what kind of crap the previous owner tried to run the motor on.

Many add a small kicker motor, for the "just in case" situations.

It is always good to error on the side of safety.

Mike