1990 Force 90 HP Outboard Smoking and Dying at idle

PLHurley5

Recruit
Joined
May 5, 2015
Messages
5
So i bought this 86 bayliner capri with a 90hp Force Outboard 2 stroke recently. i repaired some cosmetics and whatnot. When i first bought it, I cleaned the carbs and replaced the fuel lines. Lake tested it for about 30-45 min, ran great. Finished my floor repairs and stuff and took it out last weekend , ran great, cruised around, top speed great, accelerates great. but after a couple hours , went in to the marina at idle and it started smokin and dyin. starts up everytime first crank but idles rough and smokes gotta give it a bit a gas just to keep it alive. WHAT DO I DO?!?
 

SkiDad

Lieutenant Commander
Joined
Jul 18, 2010
Messages
1,518
it's hard to say without a video but it could be the timing tower on top broke or got loose - they are made of plastic. Or your fuel mixtures are way off (did you set those) ? Have you set the idle to 1000 in neutral in the water ? the idle adjustment is at the bottom of the tower with a lock nut.
 

PLHurley5

Recruit
Joined
May 5, 2015
Messages
5
honestly im a boating novice. when i cleaned the carbs, i kinda remember a screw on each carb that i turned like a turn and a quarter out. Started it off the water hose and it started and idled. It was when i just got it and it wouldnt start at all, so i did all that and it started and idled for a couple min. so i called it good and waited till i took it out. dont know what a tower is and i only have a speedometer. my mix was fairly close, i just used some 2 cycle marine oil from auto zone, nothin special. What kind of timing do you mean? Ignition?
 

HotTommy

Lieutenant Junior Grade
Joined
Mar 15, 2013
Messages
1,025
PLHurley5,
I will be surprised if anyone can help you solve your problem with the general description you have provided. You're either going to have to learn an awful lot of new information, or you'll need to turn this over to someone who knows what they're doing. .... If you're serious about doing it yourself, I suggest you start by buying a Factory Service Manual for your motor. Stay away from the cheaper, generic service manuals that are more readily available. .... If I were troubleshooting your motor, I'd start by doing a compression test on all the cylinders. But do it right or you may damage the ignition system.
 

Nordin

Commander
Joined
Jun 12, 2010
Messages
2,428
As I read your first post you have run it a couple of hours and it run good. When you cleaned the carb did you clean the hole fuelsystem?
The boat and engine is new to you and you do not know the history of it.

As HotTommy suggest, do a compression test and then you know what you starting from. If it is good numbers of the compression then you can go futher.
Clean the hole fuelsystem from tank to the carbs. Put a cheap inline filter after the fuelpump and you have a good ground to troubleshoot. You also have double filtering of the fuelsystem.
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,923
Welcome, Sounds like it might have overheated???
Start with a compression and spark test.
Then test the overheat system.
On the powerhead, there is a temp sending unit.
It has an orange lead to a junction block.
Turn key on, then ground the orange lead to the block.
You should hear a buzzer under the dash.
No buzz? Then you might have overheated?
When you mixed the gas oil.6gal to 1 pint of oil??
You add the oil first then the gas? Or the other way?

Motor OFF!!! (skidadspost)This will tell if the trigger is advancing.
Have someone at the shifter, your at the stbd. side of the motor where the shift cables go trough the cowl.
Watch the shift mechanism as someone shifts into gear.
You will need to spin the prop so the linkage doesn't bind.
Just a kick with your foot will move it enough to engage the gears.
Now as they push the throttle watch and make sure everything moves.
No broken links on the shifter.
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Whenever a Force or Chrysler engine starts stalling at idle, has a rough idle, or is difficult to start, the FIRST thing to do is clean or replace the spark plugs. Cheap. fast, and simple to do. If it does not solve the problem THEN try more complex diagnosis and repairs.
 
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