85hp 3 cylinder Force carburetor throttle plates.

[DunbarLtd]

Working on a '88 force 3 cylinder. I have synced up the shift cable and sits nicely in neutral when going through the gears. Both gears enage solid.

Now working on the throttle linkage from the tower to the roller (to check throttle plates @ WOT) and when the helm is 90 degrees (WOT) the bottom carb butterfly isnt quite flat. Maybe 90% open. The other two top carbs are perfect.

It may not be of conceren that it isnt perfectly flat but for argument sake how do I fix this so its perfectly flat with the other two carbs?

Ive pulled on the carb linkage bar and tightened the two screws like it says in the manual after disconnecting the throttle linkage rod. I cant get the bottom carb to sync up with the other two.. Dont see any adjustment on the carbs themselves. Nothing in the manual other than to adjust the length of the linkage I mentioned above until all three plates are horizontal.

 

[Nordin]

If the throttle butterflies are not equal horisontal at WOT, sync them at WOT.
Set remote control at WOT and loose the screw at throttle rod that connect the butterflies at not horisontal carb and sync it.
Check how the butterflies are at idle, they should be equal to each other.
You adjust the WOT setting of the carbs with the rod from tower shaft that is connected to throttle cam.
The last degrees of the throttle butterflies to horisontal have very little affect of the performance.

 

[jerryjerry05]

At wide open they don't have to be flat.
Just at idle.

 

[DunbarLtd]

I fiddled with the tie bar again and i think i got them as close as they are gonna get at wot.

Hey Jerry what do you mean they have to be flat (horizontal?) at idle? Are they really all the way open at that point? I never thought to look. Maybe Im missing something.

 

[gica]

Isn't there a bar that attaches all 3 carbs. On dual carbs it's pretty simple you undo the screw on the tie-bar from the starboard side of the carbs and they fall flat. At wot you adjust the throttle link and the plates move together. In between you adjust the roller. For 3 I don't know for sure but it should show similar. Don't you have a manual?
Are these the same

 

[Nordin]

DunbarLtd: I think jerry mean that the throttle butterflies need to equal at idle.
A little difference at WOT do not have any affect for the performance.
As I mention before the last degrees at WOT to horizontal have very little affect.
Gica: Yes the three carb engines has a tie bar same as the two carb engines but for three carbs.
The bar for three carbs is longer than the one for two carbs.

 

[jimmbo]

The Butterflies are to all be Fully Closed at Idle. Once the linkages between are tightened, they will all open the same amount, and there is an Stop to limit their opening. Idle Speed is set simply by adjusting how far the Timing is retarded
Just out of Curiosity.... What Service Manual are you using? If it isn't an actual Force Manual, it isn't even any good for use in the Outhouse.

 

[jerryjerry05]

Idle: the butterflies all need to be closed.
At wide open if they're not all even it doesn't really mater.

 

[DunbarLtd]

The Butterflies are to all be Fully Closed at Idle. Once the linkages between are tightened, they will all open the same amount, and there is an Stop to limit their opening. Idle Speed is set simply by adjusting how far the Timing is retarded
Just out of Curiosity.... What Service Manual are you using? If it isn't an actual Force Manual, it isn't even any good for use in the Outhouse.

Its an actual service manual. They just dont go into details sometimes if you cant get something right. In this case I think I just had to redo the tiebar a couple times to get the plates moving equally.

 

[DunbarLtd]

Idle: the butterflies all need to be closed.
At wide open if they're not all even it doesn't really matter.

Ok thank you. I understand that now. They seem to be opening correctly now.

 

[jerryjerry05]

As long as they start to open at the same time they should be ok.