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**Joe Reeves** · 04-24-2016, 06:35 PM

Compression of 120 on all cylinders is okay.

New proper plugs?... They should be either Champion L77JC4 or QL77JC4 plugs, gaped at either .040 (original recommended gap) or .030 (revised gap as of somewhere in the 1990's).

The spark (with "all" plugs removed) should jump a 7/16" gap with a strong blue lightning like flame... a real SNAP! Does it?

The high speed jets that are located in the bottom center portion of the float chambers...... have you actually cleaned them carefully with a piece of single strand steel wire? If not, do so as solvent just doesn't do that job properly.

Your comment of... "Timing advances as it should to end (doesn't even hit the stop screw). Tried moving the timing advance under load and it goes no higher. Moved it lower and engine slowed down even more."... is somewhat confusing.

By "stop screw", if you're speaking of the rubber capped stop screw which is the full spark advance stop screw, and the timer base is not slamming against that rubber cap, the engine is not obtaining its full spark advance timing, in which case it cannot obtain full throttle.... Has someone been tinkering with the threaded nylon yoke adjustment between the vertical throttle arm and the scribed metal cam that rolls against the throttle cam roller?

If so, the idle timing will require resetting as well as the full spark advance if that rubber capped timing stop screw has been moved.

**Sashapavlovic** · 04-24-2016, 07:37 PM

Yes plugs good.
Compression 120
Did spark test with gap tester at 1/2"+ connected through to plugs but never actually did with shorter. Will do.
Cleaned carbs 5 times. Can see light at bottom of holes clearly. Changed float needles. Floats all good and ensured right height plus definitely close off as they should.
Timing advance works as should and touches stop ok. Manually moved back and forth and at wot with expected result of slowing engine.
Screw that was moved was idle adjust screw . Idles fine. No one ever touched timing rubber screw. Still at same locked position as ever. Timing at idle tdc and at wot 18-19. Checked plug wires with timing light and looks ok.

**Joe Reeves** · 04-25-2016, 09:39 AM

You're indicating that you're using the proper spark plugs (Champion L77JC4 or QL77JC4), and the compression of 120 on all three cylinders is okay. You also indicate that the spark jumps a 1/2" gap with a strong blue lightning like flame (SNAP) so it would surely jump the smaller gap of 7/16", also okay.

NOTE: Be sure to check the spark while advancing and retarding the spark to see if it may be cutting out when the timer-base is rotating.

With the engine "NOT RUNNING"... remove the carburetor face plate so that you can observe the throttle butterflies. Spin the propeller and put the engine into forward gear. Now, with the control box throttle handle apply full throttle.

The timer-base should be up against the rubber stop of the full spark advance screw and the throttle butterflies should be perfectly horizontal. Are they?

Many carburetors have the ability to overrun the full throttle setting, that is the butterflies can rotate past the horizontal position and start to close again. Your carburetors could be either type.

If you have compression, proper spark throughout the timing range, and you're sure the carburetors are absolutely clean and in proper condition, synchronized, etc, the engine has to run... UNLESS... the ignition coils are not wired to the proper cylinders, water is entering the cylinder(s) or fuel is not reaching the cylinders for some reason, something of that nature.

Too bad you don't live next door... I'd really like to see that engine.

**Sashapavlovic** · 04-25-2016, 09:55 AM

hi,
thanks for the help.
The guys at justanswer.com gave up.
It bridges the gap sparking long pale sparks (but it was bright out). Can't tell if it snaps though. I have to do it in the dark. The butterflies can only go so far, I even put my finger in to move them. They go to almost horizontal, just slightly up but they "bottom out". All linkage is performing in sync. The butterflies open and go from top to middle. No water as I have changed the exhaust plate gaskets (that was happening with the water). Plugs are dry and look like they should not wet and not black, but toasty.
Can't connect the coils wrong as the wires are short. It starts and idles. Fuel is pumping.
Can I put new coils on (the new style)? Also, I can get a timer base sensor ***embly for $20 just in case that is the issue. I'm at wits end!
Tried pumping bulb when running at wot and no difference. It did bog down further before I changed the float needles, but now no change.
I don't mind throwing parts at it because I got a great boat in great shape (looks good too), motor (with problems), really good trailer all for $500! I put about $650 into motor for parts so far so I am still way ahead. The only thing left to change is the coils and stator (seems to be ok) and trigger sensor. Nothing else needs changing as it all is either new or working awesome. New head gasket and cylinder head, thermostat.
Local mechanics all have no access to lake so testing is nearly impossible. Can this be tested in a barrel?
Thanks for your efforts!

**Joe Reeves** · 04-25-2016, 11:25 AM

Unfortunately the engine can't be tested in a barrel as the problem is a "under power" problem... that barrel would be emptied in a heartbeat.

That "pale" spark should be a heavy non mistakeable solid blue SNAP... easy to see in the brightest sunlight.

Take a good close look at the stator under the flywheel. Within that green layer of fibergla$$ insulation is three large black coils (separated evenly). These three coils supply approximately 300 AC volts to the power-pack capacitor via the brown and brown/yellow wires. If any of those three coils are leaking a sticky looking substance down on the power-head or timer base, replace it regardless of whatever reading you might get on a ohm or volt meter as that would result in a voltage drop... which in turn would result in weak, erratic, and eventually no ignition.

**Sashapavlovic** · 04-25-2016, 11:47 AM

there is nothing under the flywheel but the green stator surrounding the timing base with 3 magnet triggers.
however, the stator is what you are mentioning? Then, no nothing burnt or leaking. It only has bubbles that are embedded in the casting (flattened on the outside) that look like they were from during manufacture. Does the stator not just provide charging to the battery? I can change the stator just in case. Not sure what it should look like close up.

**Joe Reeves** · 04-25-2016, 12:44 PM

That stator is a two purpose component..... those evenly divided three large black coils supply AC voltage to the power-pack capacitor.... and between those large coils are a series of smaller coils that provide AC voltage to the charging rectifier which converts the AC voltage to DC voltage to charge the battery.

If, with all he spark plugs removed, the spark is not as I have described it above in previous replies, do this....... remove the black/yellow wire (kill circuit) from either the power-pack or the ignition switch, whichever is easiest to get at. Now, do the 7/16" spark test again. If suddenly, with that wire disconnected you have ideal spark, in all probability the ignition switch is shorted in which case, replace it.

If removing that black/yellow wire makes no difference and the spark IS NOT a strong blue lightning like flame... a real SNAP... check that stator over to make sure it is not leaking at some area you cannot see with the flywheel on. Normally it is just some green looking thing with manufacturing bubbles in it here and there BUT nothing cracked, leaking, or burnt looking.

The next time you test run that engine (on the water)... try to keep it simple but at the same time explain in close detail exactly how it acts from start to finish.

**Sashapavlovic** · 04-25-2016, 04:05 PM

did the snap test again and clearly shows all ok as per your descriptions. really wide gap. Stator test as per service manual shows all within spec as per tables. Stator looks clean and in good shape. I am thinking that I might replace the stator anyway as well as 3 ignition coils with brand new ones as they may be leaking sparks at wot (I think). That being said, if the coil wires are too close to the engine anywhere I notice spark jumps but that could be because I am stressing it with a huge gap.

**Sashapavlovic** · 04-26-2016, 12:33 AM

Been going through steps I have done...
Gas shouldn't be the issue because when I pump the bulb no change in operation. All 3 plugs look the same except a bit oily (not black) due to just running at idle. Carb bowls full. Not leaking anywhere. Took head off again and looks ok and no water leakage. Will change to new style coils tomorrow but have a feeling this will not help as nothing has so far. Tested everything but peak voltage. Might change stator too and triggers pack/timing base. After that nothing else left to replace. Or check...

**Joe Reeves** · 04-26-2016, 09:20 AM

In reading back through the above posts/replies, your statement within your initial post jumps out at me. It states, and I quote:

"Starts ok, idles ok, when put under load just revs up a bit and stays there. barely 8mph. 16ft boat."

No mention is made anywhere of engine rpms... there is just a mention of "no power under load". This leads me to believe that at the mentioned "8 mph", the engine rpms has not increased.

If on the other hand, the rpms have increased to a high point and the boat is moving at 8 mph... that indicates a propeller slipping problem. Another problem that may be encountered along this line is using a short shaft engine on a boat that has a transom designed for a long shaft engine (prop too high). However, I am a$$uming that you possess the knowledge of these type errors and they do not pertain to you.

That being said.... At full throttle and moving only at 8 mph... If the timer base is hitting the full spark advance stop screw bumper and all of the throttle butterflies are fully open, possible problems are............

1 - Fuel is not flowing through the carburetors (running lean)
2 - Too much fuel is flowing through the carburetors (flooding)
3 - Water is entering cylinders
4 - Wires are crossed at timer base to pack or pack to coil connection (timing)
5 - Loss of spark as timing is advanced

I feel I've just about covered the field throughout my replies and can think of nothing further at the moment. Let me know what you find.

**Sashapavlovic** · 04-26-2016, 09:36 AM

Yeah, it's a tough one.
Rpm is low.
Pumping bulb has no effect on rpm or operation this leading me to believe that fuel is flowing as it should and floats running as they should not flooding or starving engine. Wire connection is correct. What would cause number 5? Changing all coils today. Can't see any water in cylinders. Plugs seem ok.

**Joe Reeves** · 04-26-2016, 12:27 PM

The #5 problem would be caused by the timer-base wires chafing/shorting to power-head or to the timer-base itself as they move with the rotation.

Where are you located?..... I'm near Tampa, Fl.

**Sashapavlovic** · 04-26-2016, 12:42 PM

Ok. I will change stator and timer base as well as new coils today. Can get the parts used really cheap

**Sashapavlovic** · 04-28-2016, 03:30 PM

3 new coils (new Sierra style)/wiring
Changed stator(used but good)
Same problem!
Plugs look perfect after test drive. Dry, toasty looking.
Watched carbs at wot and fuel spraying from jets in all 3.
All linkages moved freely and as far as they should.

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