1994 Force Outboard over-revving

[drafterp]

I have a 1994 Force outboard that after starting with the ears on, revs up very high. I then press in on the key to choke it and it drops down for a little then ramps right back up again and so on.... It only drops back down after either pressing in on the key or from the engine. Any help is greatly appreciated.

 

[roscoe]

Re: 1994 Force Outboard over-revving

Hi, welcome to iboats.

Could be one of several things.

First, what horsepower is the engine?

How long have you had the motor?

Is this a new issue? Did it operate properly before?


Could be stuck or mis-adjusted throttle cable.
Throttle/idle stop set too high.
Carbs set too lean.
Timing not set correctly or advance linkage hung up.

 

[drafterp]

Re: 1994 Force Outboard over-revving

Thank You! The Horsepower is 120 and I have had it for 3 years. Before this it always has run great on the water at speed without any issue. The problem with the revving has gotten worse from the end of last season and is for some reason only noticeable when the ears are on. When running it for winterization this last time is when I had to continually press in on the key to down-rev it. A boat service center has had it about 3 times and never really targeted the problem but I'm pretty sure did mess with the mixture/timing to cover up their not-knowing the real issue. I have also had a problem since the beginning of the 3 years where it stalls out after reversing away from the dock. I basically have to go from reverse to forward throttle in a split second for it to engage and get going forward. If I go too slow in no wake zone then now and again it will stall out. The service center never came close to fixing that issue so I've worked around it since. They did in the beginning rebuild the two carbs. Do I need a link and sync done or maybe a primer valve for the revving? I really appreciate the help very much...Thanks so Much!!

 

[roscoe]

Re: 1994 Force Outboard over-revving

I guess I forgot to ask high high it will rev if left on its own?

When on the muffs, there is no back pressure on the engine, so it could allow the engine to rev up, whereas it wouldn't when in the lake.

What is the rpm when in the water, at idle speed? It should be 800 rpm in the lake in gear. Roughly 1000 rpm in neutral.

The primer valve (fuel enrichment valve) appears to be working, when you press the key, it activates, and floods the engine, causing the rpm to drop.

They should have done a link n sync.

I guess I would check the timing first, and check the linkages to make sure they are moving freely.

 

[steveclv]

Re: 1994 Force Outboard over-revving

When on the muffs, even the slightest opening of the carburetor butterfly will cause it to rev very high because there is no load on the engine.

I would suggest that the carb linkages are out of sync and that one butterfly is open a fraction at idle causing the problem.

The first thing I would do would be a link and sync as you suggest. I'd also test the timing at WOT (you don't need to run the engine to do this - ask for details if you are not sure how to do this).

Those are the 2 main adjustments on the engine and if they are correct then we can start to diagnose further.

The only other thing that comes to mind at this point is a leaking carburetor gasket.