94 Force 120 dies with cap on..help

[SteveinVA]

Ok, here we go.
It runs with the cover off but a few seconds after I put it on the motor dies out. Done some searching and read it is a symptom of the carbs getting choked out by exhaust. Oh BTW it runs fine on the hose with the cover on. Also read that because the boat isn't in motion there is too much water pressure on the through prop exhaust. This motor Does have an exhaust bypass built in. Now the question, anyone know how to inspect/fix this?
I have done what I can, It looks like it is all built inside of the casting. I had the lower unit off traced out the path of the exhaust bypass. There was a thin connecting rod it looked like, connected to some sort of butterfly valve at the top near the 2 holes for the bypassed exhaust. It was loose and could be moved around alot like it was broken.
Any one have any Ideas??
I'd appreciate any suggestions
thanks

 

[jerryjerry05]

Re: 94 Force 120 dies with cap on..help



#27 on pic one,exhaust bellows#17 base seal
#45 on pic two,base plate gasket.These could be the problem?
(This motor Does have an exhaust bypass built in.There was a thin connecting rod it looked like, connected to some sort of butterfly valve at the top near the 2 holes for the bypassed exhaust.) where is this located? Picture?

 

[Jiggz]

Re: 94 Force 120 dies with cap on..help

The exhaust relief boot or bellow can be inspected easily. Any tear on this boot means you need to replace it. It's not unusual for the single spring coil or clamp holding it to break also which will allow exhaust leaks. If this is all intact, then the next thing is to check the base plate for the exhaust between the powerhead and leg, which is much harder to do but doable. To do so, you will need to submerge the LU into a large garbage can of water instead of the muffs. This will simulate the boat being in the water and inspect for leaks coming from this location.

 

[SteveinVA]

Re: 94 Force 120 dies with cap on..help

I have replaced the boot , spring, and clamp. inside the unit where the clamp holds the boot is where the pieces (butterfly thingy) I am referring to are.The connecting rod? is connected to the loose butterfly thingy and the other end is down at the bottom of the casting not connected to anything. I could grab it with needle nose at the bottom and move it all over the place.
I would take a pic but I have already put the motor back together.
Guess I 'll just wait till spring. right now the motor is on a stand, once I get it back on the boat I will test it in the large trash can full of water.
thanks for the replies

 

[SteveinVA]

Re: 94 Force 120 dies with cap on..help

Maybe this will help?
http://i1278.photobucket.com/albums/y504/audijunky_13/1994%20Bayliner%20deckboat%20Restoration/43_zps0aef8be5.png

tried to post a pic, but it made it too small to read