88' 85 hp Force fuel problem

[Striper20]

My 85 hp Force won't start. Spins over but won't bust off. Let me go over what has been done and checked.
1. Blue spark on all cylinders.
2. Fuel pump good, no tears and is pumping fuel. Fuel system is clean, new water separator filter, and lines.
3. Carbs been gone through twice, I'm confident they are working. Not my first rodeo.
4. Reeds checked and replaced.
5. Head gasket replaced.
6. Compression test, 115 on no.1, 115, no 2, 113 no.3 and compression holds on all three.
And, timing is dead nuts on it, checked yesterday.
7. No fuel is reaching the plugs, after an attempt to crank, plugs will be dry no fuel is reaching them.
8. Can spray ether straight into carbs, nothing, maybe a slight backfire on occasion.
9. I think it's sucking air from somewhere. Could the base gasket cause this issue? Or, is the problem rings, or seals?
Love the I boats forum, you guys are knowledgeable, and timely. Any opinions are greatly appreciated. I hate just running on my trolling motor. Need to get fixed asap.

Thanks,
Striper20

 

[racerone]

Does spark jump a gap of 3/8" or more, --Yes or no ?

 

[Frank Acampora]

First, are you using the correct starting procedure? Pull out the handle or push in the center button to disable shift function and push the control handle as far forward as possible. Now, push in the key and hold it in while turning to crank. This will choke the engine. Without choke and the fast idle position of the control handle a cold engine simply will not start

 

[Striper20]

Frank, I'm old school am using the correct procedure. I have a remote button have choked, carbs every way you can choke them.
Also, fast idle works have tried that as well. Everything.

 

[Striper20]

Racerone, spark arch's out at least that far. It's firing, very blue spark.

 

[jerryjerry05]

Flywheel key
You try a shot of startin​g fluid?
A one time shot won't hurt anything.

Had a problem with one of my motors.

It wouldn't start in the down position?

I had been trying for 20min to start it and had raised it to pull out.
Went to start the other motor and hit the key by accident.
It started while tilted up.
Dropped it and tried it fired right away and worked the rest of the day.

Next time? Same thing.
Wouldn't start until tilted.

Not saying yours will do the same?/
But ????

 

[racerone]

You must understand that basically you have 3 seperate motors with a common block and crankshaft.-----So if you had one bad carburetor it would run on the other 2 cylinders.----Same with a bad coil.---It would run on the other 2.-------And the base gasket does not have any affect to cause a no start condition.----How long have you owned this motor ?---And did this problem show up suddenly ?

 

[Striper20]

Haven't tried the tilt to start, will do.
Yes problem showed up suddenly/ Owned motor since June, my second power head.
So eliminate the base gasket, carbs, firing and compression, what's left?
Have tried with starting fluid and nothing backfires a little bit. I'm perplexed !

 

[racerone]

Mark the flywheel for actual TDC for # 1 and repeat with 2 and 3 ---Check and see where it fires with a timing light.-------

 

[Striper20]

Timing marks line up, dead perfect.

 

[Frank Acampora]

try removing all three plugs and pouring about one teaspoon of fuel mix in each cylinder. This will definitely flood the engine. Now crank until it clears itself See if it fires and runs on the prime shot--a couple of seconds. This will tell you that the engine can indeed run and you can go from there.

 

[Jiggz]

When you said timing marks line up dead perfect I assume that is with a timing light connected to #1 plug (top most) while cranking light should align just a little bit ahead of the TDC mark on the flywheel. Air-fuel mixture screws on all three carbs set to at least 1 1/2 turn out from lightly seated (initial setting). With correct starting procedures, get a quart or even a pint size spray bottle. Fill it half way with fuel oil mix (50:1) have someone start the engine while you are spraying into each carb. You will need to remove the air covers to do this. You can also do one carb at a time. You will need to crank it for at least 5~8 secs while continuously spraying into a carb. Try each carb while making sure it is cranking fast enough. It should at least cough or even run for a sec or two. Note which carb is making the engine cough and which one does not. If the engine coughs, you know it is a carburetion problem or fuel delivery problem.

If you have the clear fuel filter between the fuel pump outlet and the carbs' inlet and is staying at least 1/2 full then it is a carburetion problem, i.e. floats not set properly, clogged jets (most likely idle jet) or leaking carb gaskets allowing air to get in via the carb base rather than through its main opening.

If the engine did not cough at all after directly spraying into the carbs, you have spark (including timing) or compression problem (which can include water intrusion into each cylinder).

Lastly, while cranking and spraying watch for fuel blow back from the "mouth" of each carb, if it is significant it is an indication a reed valve is not seating properly.

 

[Striper20]

Thanks guys, will try tommorow. Working now. Will post results asap

 

[racerone]

Did you mark TDC by turning the flywheel to get the piston to the top of the bore.----What if the flywheel key is sheared ?

 

[jerryjerry05]

The 85/125/150 flywheel has 2 sets of marks.
3 hash marks and 1 single hash mark.
The single mark is for finding TDC.
Front of the carb top is a timing mark.
Remove the plugs, insert a long screwey in the top hole.
Slowly turn the flywheel till it's pushed out as far as it goes.
Then check the single hash mark against the timing mark.
They should be real close to meeting.​

 

[Striper20]

Checked timing with light, marks line up perfectly, as the timing hasn't been messed with. I did back up and start checking stuff again. Fuel pump not pumping. It looks good has no holes or tear. Any idea why its not working?
Replaced fuel pump with another off a junk motor, still no fuel pump pressure, or very little. Getting a tiny amount of fuel from pump.
And, tried direct injection of fuel by squirting gas into the plug hole it did backfire a few times but that's it. Not even close to starting (Yet) lol
My question is what drives the fuel pump?

 

[racerone]

Fuel pump operates on a + pressure pulse and a slight - pulse from the crankcase.--------And the fuel pump has nothing to do with starting.----It keeps the carburetors full once motor has started.------------And checking timing on one of these motors will be " perfect " all the time.------Have you checked the flywheel key ?----Or are you saying you do not need to check it after it has been mentioned a few times ?

 

[Striper20]

Have not checked fly wheel key recently. Will check tommorow. I'm off to work.

 

[Frank Acampora]

Understand that timing is only related to flywheel position because the trigger magnet is located in the center hub. The flywheel is held in TDC position by the crankshaft key. (Actually, the key only locates it while installing. Then the locking taper holds it in position) THUS it is easily possible to have timing perfect by the light, while if the flywheel has shifted on the crankshaft (because of a sheared key) It will be nowhere near what is required in crankshaft position. SO: Check that TDC on the flywheel is actually TDC of the #1 piston.

If you are only backfiring with direct addition of fuel in the plug holes, it can also be that the trigger wires are attached to the incorrect terminals. This would cause firing to be 120 degrees out of timing. OR coils or CD paks can also be incorrect. Did you mess with the ignition wiring? Then, of course, there is the rare condition where what looks like a perfectly good plug simply will not fire under compression. Throw in a different set of plugs and see what happens.

 

[Striper20]

Thanks Frank, trigger wires, all look g old and haven't been messed with. Brand new plugs. My bet is on the flywheel key. Had an issue with it about three months ago. I replaced key and put two flywheel nuts on . Didn't figure it would cause any more problems. Will pull flywheel in the morning. Work first play later. Lol.