throttle cable slack question

[MercMan82]

without moving the shifter, I can move the throttle linkage 3/8". There's so much play that at WOT, the second carb pickup is just hitting. It's completely missing the top end of the throttle. Can the cables be adjusted to fix this? I've searched this issue but came up with nothing that addresses this specific issue. Thanks.

 

[SparkieBoat]

Re: throttle cable slack question

first off it sounds like you need to do a link and sync..carbs should all move together exactly. there is an adjustment on your cable, I am not sure what condition your cable is in, but sometimes they do get stretched out or inner corrosion and need to be replaced. 3/8 inch play sounds pretty normal though.

 

[MercMan82]

Re: throttle cable slack question

i did a link and sync already. the problem is that the play messes with either the idle or the full throttle. i timed the motor and set the 1st and secondary pickups making sure all the carbs are in sync. once i put the throttle linkage back to idle, adjust the barrel and hook up the cable, it doesn't seem to go back to idle stop or if I tighten the barrel too much it takes away from the top end.

 

[MercMan82]

Re: throttle cable slack question

another way of putting it...if I push the control all the way down to wot, i can go back to the linkage and do as the picture shows, and turn the distributor from just hitting the second pickup to full throttle. That's the play that I'm talking about. The play is in the cable. The carbs and pickups are set correctly.

 

[SparkieBoat]

Re: throttle cable slack question

ok...then you may need a new cable, but 3/8 " still seems mighty small to me. check your controls and make sure you are not getting the movement in there first.

 

[Chris1956]

Re: throttle cable slack question

Mercman, Normally the Merc Control boxes have plenty of travel to overcome your 3/8" of play. Is it possible that the plastic cable end slides on the inner stainless wire? If that isn't it, check the control box for broken parts. Since you said "distributor" the proper way to set the throttle cable is to push the carbs closed (tight ot the idle stop screw) and add a bit of preload so you can feel it go into neutral. Make sure the throttle stop set screw is set to stop the carb levers before they hit the carb lever stops.

 

[Silvertip]

Re: throttle cable slack question

Cable adjustments are to adjust only for "length" -- meaning the specific distance between the exact neutral (idle) position on the control box and the exact, properly adjusted "idle" position of the linkage on the engine. They are not intended to adjust for slop in either the control box or for misadjustments of the engine linkages. As you found out, cable adjustment cannot adjust for two factors (open and closed) because that's not what those adjustments are for.

 

[MercMan82]

Re: throttle cable slack question

Chris1956 the plastic is what seems to be moving. I put the preload on the idlestop but the play within the plastic piece is what gives the inconsistency. The po said he'd replaced the control box. If it were broken, would it be at the cable ends or in the control box?

 

[Chris1956]

Re: throttle cable slack question

There should be a brass cable clamp inset into the cable end. It normally has a stainless square head screw on each side, that does the clamping of the inner cable. See if that is tight.

The real way to tighten the cable clamps is to loosen and back off both screws. Now tighten one screw until snug. Give it a 1/4 turn with a wrench. Now tighten the other screw. That procedure kinks the cable a bit and locks it into the clamp.

 

[MercMan82]

Re: throttle cable slack question

Took a look last night but couldn't find the square head screws as you mention, but I'll have a better look today and check them. I did however find quite a bit of play in the control box lever. The screw that tightens the handle into the tapered teeth of the shifter was too long, thus bottoming out in the handle before pulling it up tight. Added some washers and checked the throttle again and now I hit my throttle stops. All butterflies are fully open. Thanks guys. Appreciate it.

 

[Chris1956]

Re: throttle cable slack question

OK< sounds like you solved your issue. What kind of control box are you running?

 

[MercMan82]

Re: throttle cable slack question

Yeah I think I got it. You were right. The play that I showed in the pictures on the original post is normal. It's MercControl.