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Securing throttle control cable...help!
Posted: Tue Jul 02, 2013 10:08 am
by guy48065
My 79 Crest--nicknamed "Frankenboat" by the previous owner--had the gear control action reversed. Push forward to reverse, etc. Last weekend I took it apart & switched the cable to the other side of the bellcrank and now it works correct...almost. Problem is it "sticks" near WOT. The throttle never did this before so I don't know why moving the shift cable would have any effect on the throttle. With the end disconnected from the motor throttle lever I can move the control smoothly from idle to WOT but when I pull it back it hesitates, then snaps about an inch. In use that feels to be about a 2000 rpm drop and if anyone is standing it can pitch them forward.
A co-worker suggested Frankenboat might not have the control cables properly secured. I'll have to check this weekend but I need to know--what is "properly" secured?
Re: Securing throttle control cable...help!
Posted: Tue Jul 02, 2013 7:58 pm
by tuned
Each metal end casing on the cable housing needs to be mechanically secured. This is engineered, usually a barrel or circlip. If you did not mess with the motor end, I would be more suspicious of the controller end. I would check both anyway.
Have someone watch at the motor as you run your shifter. Also take the plate off your controller and move the lever. I would say that likely your cable is not secured properly at your controller.
Whatever you do, don't take zip ties to the entire length of your cables, especially within a few feet from each end. They need room to flex and 'breathe'.
Re: Securing throttle control cable...help!
Posted: Wed Jul 03, 2013 6:08 am
by guy48065
It's the cable flex that my co-worker cautioned me about. If the sheath is allowed to flex that movement is lost in the core, he argues. I need to know if he's right or wrong.
My sheath is attached at both ends...I think. At the controller it's anchored at the plastic gimbal that lets the ferrule pivot to follow the arc of the lever bellcrank. I can't recall if it's attached at the motor end. Weird that I can't remember--I was scrutinizing that end and even took a video of it with my camera. The core clearly jumps an inch when retracted (slower) but the sheath is stationary.
Re: Securing throttle control cable...help!
Posted: Wed Jul 03, 2013 7:05 am
by MPosey519
my new controls did that until I made sure the screws that attach the cables inside the controls were tightened down fully. They were catching on each other prior to that.
Re: Securing throttle control cable...help!
Posted: Wed Jul 03, 2013 9:04 pm
by tuned
guy48065 wrote:My 79 Crest--nicknamed "Frankenboat" by the previous owner--had the gear control action reversed. Push forward to reverse, etc. Last weekend I took it apart & switched the cable to the other side of the bellcrank and now it works correct...almost. Problem is it "sticks" near WOT. The throttle never did this before so I don't know why moving the shift cable would have any effect on the throttle. With the end disconnected from the motor throttle lever I can move the control smoothly from idle to WOT but when I pull it back it hesitates, then snaps about an inch. In use that feels to be about a 2000 rpm drop and if anyone is standing it can pitch them forward.
A co-worker suggested Frankenboat might not have the control cables properly secured. I'll have to check this weekend but I need to know--what is "properly" secured?
When this happens to me, my very first troubleshooting instinct is to be suspicious of the last area that I messed with?
First question: Did you do anything different with this cable? Different route? More wire ties? At risk of offending, is it possible that you missed a washer or something inside the controller? Or in the case of MPosey519 above, screw heads that are not bottomed properly.
From everything I've ever read, control cables need to be able to move around a bit, especially near each end (you can gently put some mounts in the middle of the run). This goes for the big fat steering cable as well. It can drag inside the cable housing (think binding). I've even experienced it first hand. Bought an old boat a few years ago that had really stiff steering. Clipped a bunch of wire ties and it loosened up some.
Here's another simple check: Unhook your throttle cable at motor end. Have a helper hang onto the cable end to 'simulate throttle spring'. Run it through it's paces. Then check the throttle action by hand with the cable unhooked. That should tell you loads about where to look. SHOULD being the operative term.
Then of course there is the cable itself, a notorious fiend in the boat game. It could just be a coincidence that it chose this time to develop a 'rough spot'. If you haven't replaced your cables in a few years, you might consider R&R them. Sometimes you can't even feel the problem in the cable, but a new one solves the problem anyway. If you don't want to roll the dice for new cables, go to a boat shop and see if you can 'borrow' an old one. Even if it isn't the right length or routing, hook it in just a swap test.
Good luck to you sir.
Todd
Re: Securing throttle control cable...help!
Posted: Sat Jul 06, 2013 2:09 pm
by guy48065
Fixed it. The hole the cables pass through was too close to the controller. Moving.the cable made the binding worse. The temp fix was to mount the controller up higher so the cables are stretched out more. Nice and smooth now.