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1994 Honda bf9.9a/15a crankcase breather issues?

S

Staying alive

Member
My Honda starts and runs fine but after awhile it will lose power and shake and rattle then if I leave it it will go back to running fine this happens intermittently , I think it is a crankcase breather problem?.
ive changed fuel pump, cleaned carb,fresh fuel. Where is the crankcase breather tube and how can I trouble shoot it ,thanks for any help. It's the kicker on my fishing boat
 
Staying alive said:
ok here's a crazy question after reading other threads --would having too much oil in it make it do that ??
Maybe I need glass's
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im going to try seafoam tomorrow . I'm going to put some in the oil and some In a small portable tank and use the spray in the carbs, smoke out the neighbours and see if that helps, maybe it's because the motor has hundreds of hours trolling
 
All of the following assumes that the motor runs ok for a while and after it warms up good...the problem happens.

My first guess would be an electrical issue. You can try the Sea Foam...if that doesn't work, take a timing light and check the spark at each plug wire and see if you see a difference or if the spark is following the uneven running. If one plug wire is different from the other, then I would look at the coil...may be an internal short to ground (or arcing to ground...taking out one cylinder intermitantly). Both spark plugs are supposed to fire at the same time. Could also be a bad spark plug. If you have not changed them since this problem started, now is the time. NGK DR5HS for BF9.9A. DR6HS for BF15A (unless you do a lot of slow speed operation....then use the DR5HS). Either could happen after the motor heats up as it is running.

If both are losing spark, then there is a common issue. First check the ground at the coil. It tends to come loose. If not, then you will need a peak reading voltmeter to check the output from the CDI to the coil and from the exciter to the CDI to see if either could be the source of the problem.

You could also remove the connectors going to the CDI unit and make sure the pins are free of corrosion. Sometimes, giving the flat pins a slight twist and reseating the connectors could improve contact.

Mike
 
Thanks Honda dude did the sea foam shock treatment and it seems to run smoother and idles better . Ran it for a long time in a tank after the treatment then shut down and ran it again after a few hours it ran good for about 10 minutes then the shaking started again I'm thinking maybe you're right and it is electrical ,I will check the ground and wires and the CDI connectors ,maybe I should just buy a new coil and spark plug wires and eliminate them. Spark plugs I change every year get them from a Honda dealer , this is my trolling motor on my 23' crestliner eagle so it does lots of hours at slow speed
 
Staying alive said:
Thanks Honda dude did the sea foam shock treatment and it seems to run smoother and idles better . Ran it for a long time in a tank after the treatment then shut down and ran it again after a few hours it ran good for about 10 minutes then the shaking started again I'm thinking maybe you're right and it is electrical ,I will check the ground and wires and the CDI connectors ,maybe I should just buy a new coil and spark plug wires and eliminate them. Spark plugs I change every year get them from a Honda dealer , this is my trolling motor on my 23' crestliner eagle so it does lots of hours at slow speed
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Ok I've been looking at my Seloc online manual for this and have read up on testing these components you suggested and I can do this , I procrastinated getting my motor in to be serviced now they are all booked up and I need to fix this myself
 
Staying alive said:
Ok I've been looking at my Seloc online manual for this and have read up on testing these components you suggested and I can do this , I procrastinated getting my motor in to be serviced now they are all booked up and I need to fix this myself
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Tested the coil it seemed to be .31 ohms it supposed to be .35 - .43 changed it with new one same thing ran good for 20 min. In a tank ,shut it off and restarted 15 min. Later ran good for a it then back to the shaking . Pulser coil was good. Can't seem to see how to undo wiring clip on CDI unit, how to get off without breaking hmmm. but have no way to test anyway, probably cost me just as much to test as get a new one,ouch.
wheres the exciter can't find on my manual
thanks
Staying Alive
 
Staying alive said:
Tested the coil it seemed to be .31 ohms it supposed to be .35 - .43 changed it with new one same thing ran good for 20 min. In a tank ,shut it off and restarted 15 min. Later ran good for a it then back to the shaking . Pulser coil was good. Can't seem to see how to undo wiring clip on CDI unit, how to get off without breaking hmmm. but have no way to test anyway, probably cost me just as much to test as get a new one,ouch.
wheres the exciter can't find on my manual
thanks
Staying Alive
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Ok figured out the connector cleaned with contact cleaner will try again if it's still shaking then it's new CDI unit
how do I test an individual wire to see if it's shorting ?
D
s a
 
Staying alive said:
Ok figured out the connector cleaned with contact cleaner will try again if it's still shaking then it's new CDI unit
how do I test an individual wire to see if it's shorting ?
D
s a
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ok finally made it do the shaking my self . While it was shaking I was looking at everything and played with the throttle linkage at the carb and made it quit right away . It appears to be something with the throttle linkage the way it's routed is suspect
 
Ok played with it for awhile and actually made it shake a couple of times and brought it back by playing with the throttle at the carb , by scientific deduction I figured I would spray carb cleaner on that throttle linkage on carb while motor was running it killed motor, restarted and did it again and saved it from dying by using the throttle , now it's idling like a champ , my question is it normal for the carb cleaner to enter the carb that way does air enter the carb through the linkage or do I need a new seal where the linkage enters the carb?
Staying Alive
 
Staying alive said:
Ok played with it for awhile and actually made it shake a couple of times and brought it back by playing with the throttle at the carb , by scientific deduction I figured I would spray carb cleaner on that throttle linkage on carb while motor was running it killed motor, restarted and did it again and saved it from dying by using the throttle , now it's idling like a champ , my question is it normal for the carb cleaner to enter the carb that way does air enter the carb through the linkage or do I need a new seal where the linkage enters the carb?
Staying Alive
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Ok I believe I should rebuild the card , any tips? I priced the carb kit at one time and it was hugely expensive up her in Canada. So I just took everything apart and cleaned it and put back together .
Is there some kind of seal in the kit for where the little arm comes through the carb body
Arrrg. Oh well at least I'm narrowing it down and I got a new coil that I didn't need
 
Well, you seem to suspect the throttle plate shaft leaking? It is possible I suppose. But, if that is what is causing your miss, it can't be repaired to my knowledge. You would just have to fit a new carb.

But, I watched your You Tube video and it sounds more like it is "skipping" on one cylinder to me. Did you try the trick of watching the spark plugs fire with a timing light as hondadude suggested? Look in the end of the plug wires and see if they seem "rusty". If the wires unscrew from the coil, look there too. If you see any rust color at either end of the plug wire, it is probably bad.

If you use carb kleener with the straw that comes with the spray can and just give it a tiny "spritz" by the end of the throttle shaft where the linkage hooks up and the motor surges...then...yes....the throttle shaft may be worn and the carburetor needs replacing.

This could also be caused by intake manifold leaks. Check and make sure that the carb mounting gaskets are sealing and that there are no loose inspection plugs in the manifold itself. Intake leaks will also show up when you "spritz" carb kleen nearby a "bad spot" and the engine picks up and smooths out for a second.

Hope you find it.
Good luck.
 
jgmo said:
Well, you seem to suspect the throttle plate shaft leaking? It is possible I suppose. But, if that is what is causing your miss, it can't be repaired to my knowledge. You would just have to fit a new carb.

But, I watched your You Tube video and it sounds more like it is "skipping" on one cylinder to me. Did you try the trick of watching the spark plugs fire with a timing light as hondadude suggested? Look in the end of the plug wires and see if they seem "rusty". If the wires unscrew from the coil, look there too. If you see any rust color at either end of the plug wire, it is probably bad.

If you use carb kleener with the straw that comes with the spray can and just give it a tiny "spritz" by the end of the throttle shaft where the linkage hooks up and the motor surges...then...yes....the throttle shaft may be worn and the carburetor needs replacing.

This could also be caused by intake manifold leaks. Check and make sure that the carb mounting gaskets are sealing and that there are no loose inspection plugs in the manifold itself. Intake leaks will also show up when you "spritz" carb kleen nearby a "bad spot" and the engine picks up and smooths out for a second.

Hope you find it.
Good luck.
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Yes I believe it's the throttle shaft (thanks for the terminology) yes I tried it again with the carb cleaner on the throttle shaft and it surges .Am pricing new carb

To go along with my new coil c/w new wires
 
The down side is that I don't think the throttle shaft "fit" on these little jewels is so precise that you wouldn't get a bit of leakage by the shaft even on a new carb.
But the upside is that these little Honda outboards are so well built, having a few spares for things that do wear out and may not always be readily attainable some fine day, will be an asset. Also makes it a sweeter deal for a prospective buyer if you ever need to go there.
I hope you're right and the new carb solves your issue.
 
Well ordered the new carb just so you know how we get bent over on pricing up here in Canada (west Coast) it's 248.00 from my dealer if I had the time to shop around I would but I don't ,,these people given lots of free advise over the years ,,so I should get it on Tuesday
Hopefully this is it!
 
Staying alive said:
Well ordered the new carb just so you know how we get bent over on pricing up here in Canada (west Coast) it's 248.00 from my dealer if I had the time to shop around I would but I don't ,,these people given lots of free advise over the years ,,so I should get it on Tuesday
Hopefully this is it!
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It better work I'm running out of parts to replace!!!
 
Yes, the price does seem a little high, but hopefully, they will also give you some thoughts on the matter.

One question......does this miss occur at high speed? Or does it run smooth?

Mike
 
Well, hindsight tells me that I should have urged you to check your valve adjustment and timing before you ordered the carb. I hope the swap works but if it doesn't, checking those settings is where you'll be headed next. That and a proper compression test will be necessary for a decent assessment of what needs to be done next.

I'm xing my fingers that the carb does the trick. Can't wait to hear how you make out!

Best of luck.
 
jgmo said:
Well, hindsight tells me that I should have urged you to check your valve adjustment and timing before you ordered the carb. I hope the swap works but if it doesn't, checking those settings is where you'll be headed next. That and a proper compression test will be necessary for a decent assessment of what needs to be done next.

I'm xing my fingers that the carb does the trick. Can't wait to hear how you make out!

Best of luck.
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I've got my fingers crossed if it's the valve adjustment sounds like I need a special tool
 
One other way out there thing ......it could be is the timing advance springs under the cam pulley sticking in a position for higher speed operation...but once in a while they break free and operate as they should.

Mike
 
hondadude said:
One other way out there thing ......it could be is the timing advance springs under the cam pulley sticking in a position for higher speed operation...but once in a while they break free and operate as they should.

Mike
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Here's my question for the day I'm going to adjust the valves which ones are intake and which ones are exhaust I'm assuming from the top down its intake ,exhaust ,intake,exhaust , all the information I've got cant find anything to confirm it for me , and yes the gaps are a little big right now by about 0.03 on all of them I've figured out which are intake and exhaust by the gap they are now but would sure appreciate a conformation
thanks
Simon in BC
 
Staying alive said:
Thanks Honda dude I was just putting water in the tank to fire it up now to open it up again
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If that's the case then the valve adjustment was way off will check with my dealer to be sure and do it tomorrow but yes the middle ones seem to line up with the intake was probably my problem all along
oh well now I have a new coil and carb , any tip on any adjustments I may need to do on a new carb
thanks
simon
 
Just for the sake of discussion....First, I concur that intake valves are the two in the middle and exhaust are the two at each end of the cylinder head.

Second, valves usually get TIGHT over time with wear as the valve slowly sinks down in it's seat and the stem gets closer to the rocker arm. If the valve adjustment gets too tight, the valves can be held open and loss of compression and burning of the exhaust valves can occur. On some engines a very tight valve will actually allow the piston to contact the valve face because it is held too far off of the seat. This results in major damage that can destroy an engine.

Loose valves could mean that they were improperly adjusted or that someone left the locking (or jam) nuts loose and the adjustment backed off. But know that a loose valve adjustment, while not ideal by any means, is less likely to cause engine damage than a tight adjustment.

So, if they were loose and not tight the valves and engine are likely NOT to have suffered any ill effects.

I don't know if that carburetor has a "limiter cap". If it does, and it comes already installed, then the only adjustments you can make are to ensure that the throttle plate opens completely at full throttle setting and that the idle set screw holds the throttle plate slightly open for a base idle setting. In other words...so it doesn't stall at idle while in gear.

If no limiter cap or, if it comes in the package with instructions to glue it on, then an idle screw setting of 1 1/2 to 2 turns out from fully seated should get you started and you can fine tune after the engine is warmed up.

I hope this gets it done for you.

Good luck and keep us posted.
 
jgmo said:
Just for the sake of discussion....First, I concur that intake valves are the two in the middle and exhaust are the two at each end of the cylinder head.

Second, valves usually get TIGHT over time with wear as the valve slowly sinks down in it's seat and the stem gets closer to the rocker arm. If the valve adjustment gets too tight, the valves can be held open and loss of compression and burning of the exhaust valves can occur. On some engines a very tight valve will actually allow the piston to contact the valve face because it is held too far off of the seat. This results in major damage that can destroy an engine.

Loose valves could mean that they were improperly adjusted or that someone left the locking (or jam) nuts loose and the adjustment backed off. But know that a loose valve adjustment, while not ideal by any means, is less likely to cause engine damage than a tight adjustment.

So, if they were loose and not tight the valves and engine are likely NOT to have suffered any ill effects.

I don't know if that carburetor has a "limiter cap". If it does, and it comes already installed, then the only adjustments you can make are to ensure that the throttle plate opens completely at full throttle setting and that the idle set screw holds the throttle plate slightly open for a base idle setting. In other words...so it doesn't stall at idle while in gear.

If no limiter cap or, if it comes in the package with instructions to glue it on, then an idle screw setting of 1 1/2 to 2 turns out from fully seated should get you started and you can fine tune after the engine is warmed up.

I hope this gets it done for you.

Good luck and keep us posted.
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Ok set the valves put in the new carb it ran nice ran for 15 min in the tank shut it off waited 10 min started again and the shaking happened again I'm pissed now
So I'm running out of parts to change what does the CDI unit do I have no way of testing it.
 
Staying alive said:
Ok set the valves put in the new carb it ran nice ran for 15 min in the tank shut it off waited 10 min started again and the shaking happened again I'm pissed now
So I'm running out of parts to change what does the CDI unit do I have no way of testing it.
Click to expand...
One thing I never checked was the rectifier will do that tomorrow
 
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