Timing?

tshupe5 · Nov 11, 2008

What are the chances of timing being the cause of an intermitent RPM?I am out of money at this point. This problem has drained me for about $500 to date. New fuel pumps. cleaned carbs, water separator, plugs, primer ball and hose. I took my pickup tube out of main tank today and found some junk in the screen but not confident that is the issue. I have aux tank and have tried switching tanks while problem happens with no change. I took apart all fuel lines from the valve to the carbs and found no issues.Out of hope at this point. Anyone know a good mech in the Ocala Fl. area?

James R · Nov 11, 2008

Re: Timing?

It would help us greatly if you would tell us what motor you are refering to.

rodbolt · Nov 12, 2008

Re: Timing?

what are the chances we know what Your working on?
but in general NO, you dont have a timing issue creating an intermittant problem.
most outboards use a mechanical timer to control timing, its either right all the time or something is worn out, the rest use a variaty of TPS or ECU ,or both, controled timing methods with the pulser coil fixed at 7 or 10 degrees BTDC.
if timing is off on those motors something is broke.
without more information thats about all I can say about ign timing on an outboard.

tshupe5 · Nov 12, 2008

Re: Timing?

1987 Yamaha Pro V 150

Silvertip · Nov 13, 2008

Re: Timing?

Intermittent RPM means what to you? Intermittent means sometimes you have some RPM and sometimes you don't. How many RPM you have depends on where the throttle is set. Now if you have an intermittent something, it causes a drop in RPM. So when this "intermittent" happens, what RPM was normal and how much of a drop did you notice and for how long. That's the important part of the description of the problem. I suspect you have a misfire on one or more cylinders. That could be a spark issue or a fuel issue but definitely not a timing issue. Have you at least pulled the spark plugs to see what they look like?. When were they changed last? You said you cleaned the carbs. But how well did you clean them and were they fully disassembled, soaked, blown out with compressed air and did you ensure every passage was squeaky clean? Were they assembled with new kits and were float levels properly set.

tshupe5 · Nov 13, 2008

Re: Timing?

I cleaned the carbs without soaking the bodies. Rodbolt insisted to not soak them.I tore down all jets, bowls and repaced whatever came in the kits. The plugs look like they are fireing as well.If i pulled each plug while running on the hose and had spark does that mean it is good?Or while under stress of higher RPM is it possible that a coil might fail?I am getting very short periods of normal running but that does not last long. It seems like an electrical shortage.The more turbulance i can create, the more upward RPM i get from it even though it cannot be controlled.

Silvertip · Nov 14, 2008

Re: Timing?

[QUOTE} The more turbulance i can create, the more upward RPM i get from it even though it cannot be controlled.[/QUOTE]

Now I'm really confused. What "turbulence" are you creating?? The throttle is used to control rpm -- if the engine is over reving pull it back. Normally when an intermittent condition exists the engine runs normally then begins to SLOW -- not speed up. If the engine seems to suddenly rev up there are other issues. Are you absolutely certain the engine is running properly INITIALLY, and then begins to act up, or is it possible the engine is NOT operating properly initially and suddenly begins to run normally? Prop ventilation or a spun prop hub comes to mind. Back to the spark issue. Just because there is spark at a cylinder does not mean that cylinder is firing. That spark needs to ignite a fuel/air mixture so it that's missing, that cylinder makes no power.

tshupe5 · Nov 15, 2008

Re: Timing?

yeah i know it sounds confusing.It is because i was not sure how to describe what happens. I will try to be more precise. I put the boat in the water, pull the choke, prime the ball and it starts right up and idles great. I turn the choke off and idle outside of the no wake zone. I floor the hotfoot and get up on plane quickly, run on plane for a few seconds while speed is building along with RPMs. Up to this point i have not noticed any problems. Then suddenly once we are at what seems like WOT, the lowering in RPMs comes and takes the motor down like it has a governor and will from that point on, start to in no apparent pattern start to kick back in and then back down again, back in and back down. RPMs stay down longer than when they kick back in, like when they do kick in it is only for short bursts.Hope I am more clear.

rodbolt · Nov 16, 2008

Re: Timing?

this motor uses a 3 pulser coil movable trigger and a high and low speed charge coil built into the stator, electrical problems are rare but very easy to find.
its a basic ADI ignition system.
at a minimum you will need the test harness to check pulser coil output voltage,charge coil output voltage and CDI output voltage.
if all outputs are correct and stable at the problem RPM go fix the fuel issues.
have you tested your audible alarm system to make sure the CDI isnt going into RPM reduction in an attempt to save the powerhead regaurdless of the helmsman?

tshupe5 · Nov 19, 2008

Re: Timing?

Rodbolt, you always impress me. No I am not sure if the CDI is going into failsafe mode.I have considered it. I have tested the buzzer and it is buzzing when i plug the pink and black wire together from the head area. Is there a way I can troubleshoot the CDI warning system?My guess and work on the motor to this point, is that the CDI is going into failsafe mode for whatever reason. I have not put in a waterpump and i have had the boat for 3-4 years. I am hoping that the pump is weak and is not cooling the motor to specs therefore sending it into failsafe. I live in NorthCentral Florida and the waters have gotten 20-30 degrees cooler since the problem started and I have seen a increase of RPMs and length of time able to run at higher Rpms as the water has been cooling. Maybe the cooler water is keeping the temp of motor down?If the problem is still there once i replace the impeller then i will have to save some money and take it in and cross my fingers that i get someone that knows how to troubleshoot properly.

rodbolt · Nov 20, 2008

Re: Timing?

to test the oil alarm simp-ly drain the engine oil tank via the vynil water trap tube and turn the key to on,you should see flashing lights or bars on the tach and an audible alarm. tank should refill and shut off in 180 seconds.
make sure the remote tank is filled at least 1/2 full before testing.
best I remember on that system the key has to be cycled off to reset the alarm condition but I cant remember.
if you suspect a false CDI alarm signal remove the pink wire from the CDI and try again.
other than that its break out the test equipment and go chase the issue.

tshupe5 · Nov 26, 2008

Re: Timing?

I am going out tommorrow and going to unplug the pink wire from the CDI. Hope to get closer to resolve this issue that has dragged on for 5 months now.

rodbolt · Nov 27, 2008

Re: Timing?

My guess and work on the motor to this point, is that the CDI is going into failsafe mode for whatever reason. I have not put in a waterpump and i have had the boat for 3-4 years. I am hoping that the pump is weak and is not cooling the motor to specs therefore sending it into failsafe. I live in NorthCentral Florida and the waters have gotten 20-30 degrees cooler since the problem s
what? thinking it may be overheating your going to dissconect the engines last point of protection?
man I gotta see the burned piston post.
why not simply either purchase the tooling needed to correctly and quickly diagnose the problem or take it to a shop?
have you tested the oil alarm like I posted to insure its functioning?

tshupe5 · Nov 29, 2008

Re: Timing?

I dont know what to do other than take it in after trying to test the oil alarm system like you said Rodbolt. I am strapped for cash after buying all these other parts while troubleshooting.If i knew how to perform these tests that are simple for you, I would have bought the equipment a long time ago.I wish you were in my area so i could pay you to test it for me.I am going into the back yard right now to drain the tank to check alarm. Thanks for the expert advice once again.

rodbolt · Nov 30, 2008

Re: Timing?

very sorry you have spent so much and no results.
most of what you have done though is maint actions.
remember, to test the oil alarm : key on engine off.
cut the tie strap on the vynil water trap on the engine oil tank. carefully work the tube off the tank nipple.
drain oil into a suitable clean container until the level drops below the second mark, once the alarm sounds reinstall the trap and see how long it takes the transfer pump to refill the tank, should happen in about 180 seconds.
to find a dealer in your area with a master tech google yamaha marine dealer locator.
if you cannot find a dealer with a master tech look for the electrical and fuel school certifications on the wall.
do you have the digital guage package on your hull that gives oil and overheat visuals ?

tshupe5 · Dec 9, 2008

Re: Timing?

I believe I do have specs on those things on the inside of my reaer lids.I have a Skeeter bass boat.Thank you for the advice on finding a master tech or someone that has the fuel and electrical cert.I am taking the boat to my friends house to replace the impeller and housing since it has not been done in at least 4 years. He seems to think my power loss may be related. I told him I didn't think so since you"Rodbolt" had not mentioned that as a possible.After we install the impeller I will have to take it in for testing.Oh yeah, I did test the oil alarm system and it is functioning properly.So techs have equipment to test a problem that occurs at high RPMs and under demand right there in the shop without putting the boat in the water?

rodbolt · Dec 10, 2008

Re: Timing?

now your putting words in my mouth I did not say.
if you had the correct rigging you would get a visual indicate as well as an audible indicate for either overheat or low remote tank level or engine oil tank level.
when you change the pump, replace the pressure control valve grommet.
carefully clean the grommet pocket.
for years I had an IDC 3200 series outboard engine Dynamometer,now its at Ron's marine in portsmouth. that particular Dyno had left or right hand input and could properly load outboards to 225HP and stern drives to 250 HP.
now I use the test wheel and back them over or use the test leads and a multimeter and water test it.
they make thermomelt sticks in all ranges of temps, can aide in finding overheats as well as using an infared temp gun or a temp probe on your multimeter.
not all shops have the test equipment nor the trained techs to run it.
some of us try harder than others.
if ya wanna play the game then purchasing test equipment and manuals is just a simple fact of life.
you could have trash in the carbs,fuel pumps,fuel line fuel draw tube,an overheat a slow oil transfer or a myraid of issues.
you have to address each one and eliminate it as a culprit.

Timing?

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