1990 Force L-Drive 90hp -- Can't get it to idle -- losing my mind :D

[Solace]

I’m using logic here dude, but I understand your comment. It’s gota be floats are closed to early. Gota be. Or I have bad compression but that was tested recently. And I KNOW I adjusted the floats to be even, which may be too low.

 

[racerone]

I am not a dude !!----Good luck with this machine.----I can not offer any further advice without some beer tokens.

 

[jerryjerry05]

Hey, I'm also using Octane 87, I can get either 91 or even 94 -- will try when this tank runs outa gas...

I have replaced the Anti Siphon valve and rebuilt the fuel pump diaphragm, checked for debris, and carbs are rebuilt. Could it be float bowl adjustments?

Octane will make no difference other than the higher octane used for extended periods can cause damage, burns too hot. Search Google for the difference in the octanes and the results of running the wrong one.
All you need is the 87
You have plastic or metal floats in the carbs? Make sure there's no holes in the metal ones. Float level and drop need to be right or it will starve.
How easy does it start? Hard turning over? do a compression test with a "GOOD" tester. Brand new testers(Harbor Freight) can give bad results right out of the box.
Timing, like Racer suggested: timing light without a dial or meter, just a plain old light, or turn the dial to ZERO and use it then.
If you had the timing set at 28 or 32 you should be able to rev to 5500 if things are set up right. Setting to the end result of 28/30/32 is for fine tuning and making it last longer and get better fuel and performance.
That's all my brain can think of this early in the morning.
Not revving up in gear: what you using for a prop?
The wrong one can drop the rpm's by a 1000rpm's if it's the wrong one?

 

[jerryjerry05]

One more: compression can change from one day to the next.

 

[Redbarron%%]

Have you checked for spark on each plug with your timing light running?
Sounds like you have at least one dead Cylinder.
Also your timing light is probably for 4 stroke engines and reads one spark firing per two revolutions.
That means that your 2 stroke is firing twice as often and the rpms are reading twice as high as the engine is turning (assuming no switch for 2 stroke.) So 3500 rpm on the meter would be only half that or 1750.
If using the tach on the 4 stroke light the idle rpm set to "spec" out of the water would definitely stall in the water when put in gear.
The video sound like there is not much power being produced.
2 Stroke engine sound smoother that a missing cylinder on a 4 stroke as there are twice as many firing pulses.
Bad trigger coils are common and therefore not firing one cylinder is also common.
As far as using logic, Dude, I see very little of it applied by you in this exercise. Step by step, verify what you measure, don't jump around and pay attention.
I am not that experienced, but I have made most of the mistakes in getting my 90 hp Sport Jet running. Jerry and the others are very experienced working on these engines and deserve your attention and respect.

 

[The Force power]

Here's the link to diagnose the ignition system
At this point I would do this first!! so that that part of the equation is done.
https://www.cdielectronics.com/wp-content/uploads/2013/02/CDI Troubleshooting Guide - 2012.pdf

 

[Solace]

Floats were way off, fixed that, installed new bellow.

engine no longer stutters, sneezes, or randomly shuts off — smoooooth. Had to slightly adjust air mixture, but still no actual improvement. Still only getting 7mph.

 

[Redbarron%%]

Did you check for spark on each cylinder with your timing light?
Still sounds like a dead cylinder and low power.
Your video did not sound like you were turning up much RPM.
Step by step.
Unloaded and engine will turn up a lot of RPM. loaded not so much.
I have dealt with a dead cylinder myself, but it would turn almost 4000 rpm and plane out, but the boat was a lot smaller (15'10" Hobie Jet Fisherman)

 

[Solace]

Did you check for spark on each cylinder with your timing light?
Still sounds like a dead cylinder and low power.
Your video did not sound like you were turning up much RPM.
Step by step.
Unloaded and engine will turn up a lot of RPM. loaded not so much.
I have dealt with a dead cylinder myself, but it would turn almost 4000 rpm and plane out, but the boat was a lot smaller (15'10" Hobie Jet Fisherman)

Yes on spark, timing gun flashing nice and solid on each one. Wonder if my plugs are toast, been 4 months torture on them now.

 

[Solace]

Vid didn’t upload

 

[Solace]

Jumping all over the carburetors for the 5th time might not fix it.-----As suggested you need to do some orderly trouble shooting !!!

Hey, actually my floats were super outa whack. It was causing sputtering and sneezing -- I think the bottom carb had a slow flood. It's PERFECT now!

 

[Solace]

..

 

[Solace]

3rd time is the charm.... Here's my most recent run.

 

[jerryjerry05]

Are the carbs opening at the same time? You have 2 butterflies, one for the choke and the other inside the carb. The choke should stay open unless you hit the choke. The other(inside) should all move at the same time as you throttle up.
You have the regular choke or the primer system? If the primer is there?? try pinching off the hose to the carb/s. It has a rubber diaphragm that can go bad and allow excess fuel into the system slowing down the operation.
Starting fluid test: can of sf, spray around the intake side of the motor, under the packs and coils and at the base of the carbs and the 3 port covers. If doing this makes any difference then it's sucking air somewhere and needs to be fixed/resealed?
One tiny cough, backfire, stutter can blow the port cover gaskets.
Is there a snout on the lower unit? #13 HAS to be there.
What prop? through hub or solid? What pitch? Condition? Pics
It sounded like the idle was set a bit low??? What rpm's is it set at?

 

[Solace]

Going to fill Woth 91 octane and try it again, will have working tach this time.

Electric choke solenoid I’m working order, it’s for sure open choke in the video above working correctly, all butterflies are link synced to spec.

Im running this for a prop, brand new not spun:
Qiclear Marine 13 1/4 x17 | 48-77344A45 (Hub Kits Included) Upgrade Aluminum Outboard Propeller fit Mercury Engines 60-125HP,15 Spline Tooth, RH https://www.amazon.ca/dp/B07VYR7Y54...t_i_FK5VJG7341YXV3S89B3V?_encoding=UTF8&psc=1

 

[Solace]

I also had a 1929 prop that produced the same result, also another that didn’t improve speed

 

[The Force power]

I also had a 1929 prop that produced the same result, also another that didn’t improve speed

How are you measuring your speed? the Tach in the boat? OR by GPS?

 

[The Force power]

Going to fill Woth 91 octane and try it again,

Yeah....increasing the octane will cure all your problems.
AS you told earlier....that your fuel/oil mixture was waaay off
The correct thing to do is;
Empty your tank and fill it with the correct mixture
while you do that, I'm going to the kitchen to get more popcorn

 

[Redbarron%%]

What part of step by step following instructions is so hard?
Step means one increment.
One step at a time. Follow instructions.
Eliminate one issue at a time and work your way to the answer.
You have spark on each plug.
Assuming that the timing is set correctly (not in evidence as yet.
Carbs dingled with perhaps floats correct, cleaned and blown out.
Still do not know if you have done Link and Sync (properly or not)
No trusted tach to set idle or see what RPM you are turning.
Note the engine initially speeds up mostly on timing increase. The cam opens the throttles quickly after maybe 1/2 throttle. The throttle can be backed down from WOT and the spark advance stays for a little economy at cruise.
If you are not getting on a plane either you are not producing power (still no RPM from a trusted tach), the boat is heavy and waterlogged, the prop is cavitating (would produce high rpm and no thrust), or the prop hub is slipping (still high rpm and no thrust.)
The videos don't sound like the engine is very peppy and RPM is low. My 90 hp sounds like it has more RPM and throatier.
Personally I would tie the thing to the dock so I could look closer at what is happening with a safety helper working the throttle.

 

[The Force power]

What part of step by step following instructions is so hard?
Step means one increment.
One step at a time. Follow instructions.
Eliminate one issue at a time and work your way to the answer.
You have spark on each plug.
Assuming that the timing is set correctly (not in evidence as yet.
Carbs dingled with perhaps floats correct, cleaned and blown out.
Still do not know if you have done Link and Sync (properly or not)
No trusted tach to set idle or see what RPM you are turning.
Note the engine initially speeds up mostly on timing increase. The cam opens the throttles quickly after maybe 1/2 throttle. The throttle can be backed down from WOT and the spark advance stays for a little economy at cruise.
If you are not getting on a plane either you are not producing power (still no RPM from a trusted tach), the boat is heavy and waterlogged, the prop is cavitating (would produce high rpm and no thrust), or the prop hub is slipping (still high rpm and no thrust.)
The videos don't sound like the engine is very peppy and RPM is low. My 90 hp sounds like it has more RPM and throatier.
Personally I would tie the thing to the dock so I could look closer at what is happening with a safety helper working the throttle.

Why? its the 91 octane that is missing