Throttle linkage and carbs

[mick97]

1985 force 85hp
At what point do the throttle plates(back butterflies) open?

It boggs down at wot.
Actually takes off for 3 seconds,then boggs.

I took it to the point where it it boggs,then went to the motor and hand throttled it,and it seemed to come out of it.Couldn't do it for too long as i was alone,and no one to steer....lol

Seems the top linkage goes 1/2 or less,then the bottom linkage takes over when using the throttle.Kicking it into high so to speak.

But by doing it in the drive way,seems like the back throttle butterflies are not opening until the last 2 inches of throttle up front.

Never have seen the choke work,but just guessing thats allright,as when i hit the choke on the key,they shut quick and fine.

Any thing to check when i got it in the water tomorrow?
Whats the procedure for sync?
Unhook the 2 cables on the motor when the throttle up front is all the way up,and re attach?

Thanks,
Scotty

 

[pnwboat]

Re: Throttle linkage and carbs

The easiest way to do sync up the throttle plates is to disconnect the small shaft with two plastic ends that connects the tower shaft to the throttle cam on the bottom carburetor. This way you can work the throttle cam by hand and visually check the throttle plates in all carbs. To get the shaft off without unscrewing the ends, I take a small open end wrench like 3/8 and slip the open end between the plastic and the throttle cam. Kind of like a fork under the plastic end. Slowly lift out on the end of the wrench, and it pops the plastic piece off of the connecting pivot ball. Be careful because if you break that plastic piece, it may no longer stay out like it should. You could also be safe and just make a note of how many threads on the shaft are showing and unscrew it.

There are some screws on the rod that connects all the throttle plates that you use to alter the length to get the throttle plates in sync. The carbs should be sync'd off of the bottom one.

Yellow arrow points to the shaft.

 

[mick97]

Re: Throttle linkage and carbs

So number 1 is where i adjust correct?

I moved the cam by hand and looked into the carbs.Looks all pretty close from what i can see......

Just was wondering why it seemed to run when i went to that bogg down spot,and then went to the back of the boat,and ran the cam by hand,and it seemed to come out of it.
Closing it more that is,so the butterflies were closed more...

Almost like wasnt getting enough choke or something.


Also,what is the switch on the bottom of #3 on the photo?
Seems like it barely touches the button on the bottom.

Scotty

 

[pnwboat]

Re: Throttle linkage and carbs

Yes number 1 is where you adjust.

Sounds more like you're running lean. Hard to tell without actually being there. Have you tried squeezing the primer bulb to see if it has any affect? If that cures the bog, then you probably have a fuel delivery problem. Did you ever get around to replacing the fuel pump diaphragm?

That switch (#3) is your neutral safety interlock switch. With the throttle control in the neutral position, the cam or plate on the linkage pushes the little white button in to complete the circuit so you can energize the starter solenoid. If you move the throttle control forward or reverse, the little cam or plate moves so it no longer pushes the white button in preventing you from starting the motor in gear.

 

[mick97]

Re: Throttle linkage and carbs

Yes I tried the bulb thing.Made no difference.
No i didn't get a new diaphram yet.

Sure didn't look like the other one was bad though.


Ok,got cha on the switch.

Ya got to be some type of fuel delivery problem I would think.

Seems odd that i get it in the bogging position on the throttle,then go to the motor and fool with the cam for all 3 carbs,and it seems to come out of it.
Cant really remember what i did.will have to try it again tomorrow.

It seems like i opened up the cam for the 3 carbs,and kinda fooled with the choke.Outside butterflies.

I will have to keep a little better track tomorrow.

So im really guessing it might not be abythingf with the sync.
Scotty

 

[mick97]

Re: Throttle linkage and carbs

Ok,

Took it out finally.
What I did was push the throttle foreward until it bogged down.
Then I went to the motor and opened the carbs up,whilst playing with the outer 3 butterflies.(choke im taking it)

Got it to open wide up,and would of plained out if i had someone in front.
So the trick is getting both the choke and the cam(3 inner butterflies) to a certain point.

The first time i tried it,it didn't work because evidently i had to go up to the front again,and push in the throttle handle some more.

Bogging 3/4 throttle,then i could go back and get alot of power out of it.

What would be the deal here?
Is the 3 outers suppose to stay open all the time except for when you choke it?Never have seen them move except when i choke with the ket when im starting it.......

I also noticed a couple of times when i tried it,,,,I went wot,and when it bogged down,i hit the key choke real quick a couple of times,and noticed that for a mili-second,it seemed like it came out of it and was fine.

Any other advise here?

I guess its starving from no gas hu?
i choke,and it works??? Weird.

Tomorrow im gonna have someone with me,so i want to really open it up to see if i can run it from the motor end,and get it plaining.
Curious

Scotty

 

[bashr52]

Re: Throttle linkage and carbs

Verify with engine off, in your driveway or something, that at WOT the distributor advances to the stop, timing is correct, and then adjust the linkage rod to open the cam so that the bottom carb opens fully (butterfly horizontal). Then loosen the linkage screws and adjust the other 2 carbs so they are open the same amount.

If that is all setup correctly, and you have to partially close the chokes to get it to run right, you're either running lean or starving for fuel.

 

[mick97]

Re: Throttle linkage and carbs

Not quite sure if I understand.

I did have it in the driveway yesterday.
I opened the throttle 1/2 way,and by looking in at the but-flies,they were barely open.

Then wot with the throttle,the carbs were horizontal.

Not much difference as you go over the hump that opens and closes the carbs,until the last 2 inches of throttle,and then it opens the carbs horizontal.

scotty

 

[bashr52]

Re: Throttle linkage and carbs

That sounds about right. At WOT you want all three butterflies to be in the same horizontal position. Sounds to me like you may have a couple plugged main jets. Adding choke richens the mixture up, and gives you the boost in RPM's.

 

[mick97]

Re: Throttle linkage and carbs

Ok,

Well mabe it was me after i tried doing that again...lol
I just ordered a couple diaphrams,and should be here by saturdat hopefully.
That will be a first step.

Also,on timing it,do you know how to do that?
in the picture below(1)is that the part under the flywheel that i move to advance timming?
I was reading up on this on another thread and just thought i would mention it here.

I only see 2 lines on the side of the flywheel.Seems to me others have said theres 4.....28-30-32-and a blank one or something.

Mine is just 2 lines,and the space between them is like3-4 inches apart on the side of the flywheel.

Thanks,
Scotty


Thanks,
Scotty

 

[maxum_man]

Re: Throttle linkage and carbs

the line on the right should be 0* or Top Dead Center. The line on the left should be where you want it set at, whether it is 28 or 30 or 32, whatever your timing is supposed to be set at. I am not 100% on that, but that is how it should be. Yes the screw with the lock nut is for adjusting your timing. Turn it clockwise to advance and counter clockwise to retard. Timing should be checked in neutral at WOT at cranking speed.

 

[mick97]

Re: Throttle linkage and carbs

Thanks..

Its a 85 bayliner.I don't believe the handle comes out so i can open it wot...
Any other way to do it?
scotty