This one will get you thinking

[trent750]

Re: This one will get you thinking

Thanks for all your time and energy I will pm them as soon as i figure that out. Thanks again, if you come across any help please let me know.

 

[jay_merrill]

Re: This one will get you thinking

My vote is on ignition and I'd bet it is either the powerpack or timer base.

Take an inductive timing light and tape the trigger shut. Hook it to your battery and put the "clip on" around the plug wires, one at a time. Shut the motor down before changing from one wire to the next. Place the light on the deck or a seat, so that the light can be view easily.

Use the light while running the boat in open water, to see which cylinder, if any, is breaking up.



???

 

[trent750]

Re: This one will get you thinking

So here's how today went. I sealed the tube, just in case. Put in a set of Q78YC plugs and went off to the lake. Started it up and drove it around to warm it up. Once warm I tried to go just above an idle. NO change at all. Because I have OCD I had to try to adjust the throttle link to bring the timing advance in sooner, It solved about 50% of the problem. I wanted to idle it around to see if it would smooth out any more but instead it picked up a cough at idle in gear. I had a timing light with me and checked, but the idle timing was still at 8 atdc. I usually run the extended idle QL82C plugs (thats what the SELOC book said) but for today I tried the others. I'm hoping the cough was due to the resister style plugs and alot of idling (probably 45 minutes). Also the plug I put in it today were not new ones, just some pretty clean ones I had taken out last year, Maybe 3 hours on them.

 

[jay_merrill]

Re: This one will get you thinking

The point of the timing light is not to see where it is timed - its to see if any of the ignition circuits are breaking up. By running the motor under a load and testing at each spark plug wire, you can find out if you have intermittent ignition - especially at the rpm range in which you are experiencing problems.

All I am trying to get at here, is whether you have an ignition problem or a fuel problem.



???

 

[trent750]

Re: This one will get you thinking

Yeah I knew what you were trying to do but I just forgot to do the test after all that time on the water (alittle fishing to). I just found out I put NGK plugs in it instead of Champion. This motor doesn't like NGK plugs, I bet the cough is gone now that I just switched to another set of Champion plugs. Thanks for all the help I have to work for the next few days so I won't have any time to tinker.

 

[Dhadley]

Re: This one will get you thinking

You mentioned you have the linkage set so you pickup timing first and then the carbs. It should be the other way around.

The emulsion tubes can be changed. Look at yours very closely to make sure it's not eaten up or cracked.

Don't get hung up on an exact number for the idle timing. If the carbs are claen and shut properly at idle then the idle is adjusted with idle timing. Could be a degree or two either way. A lot depends on ehaust backpressure etc.

 

[BubsBoat]

Re: This one will get you thinking

it may be different between omc and mercury but when i was in one of the Mercury University classes the instructor bugged an outboard engine with a bent reed (not broken) and it performed exactly as you have described. my suggestion would be to pull the reed block and check the gap or pre-load on the reeds.

 

[bktheking]

Re: This one will get you thinking

Are the emulsion tubes a different style? Not seeing them in the diagram as a part, just curious for my own knowledge, always thought they were part of the carbs.