Mercury 650 Thunderbolt throttle adjustment

[Snatchymanx]

Engine runs fantastic, it's a 1969 65hp. I'm an aviation tech by trade, dipping my feet into the outboard world.

From the day I got it the throttle was odd. There was so much resistance going from full throttle FWD back to N and R, and the gear level/throttle cable wasn't even actuating the throttle. I put new Teleflex cables in it and we took it out on it's maiden voyage today.

Shifts great after the cables, yet still no throttle with the main lever. I could only use the fast idle lever to get it to really move in the water and it was balls slow. Went back to dock 2-3 times and kept adjusting the cable until I ran out of threads and it was immensely better but not 'right'.

D/C'd both cables and my brother drove while I sat on the back and actuated the throttle lever manually. Holy sh*t, thing hauled balls and sounded amazing (confirmed it was not carb related). We loaded it back up and went back to the house.

Dug out all the old hard grease around the dizzy and pumped in fresh grease. Still couldn't get the throttle lever to actually control the throttle, it was just gear then nothing all the way down (however, it would actuate the throttle in reverse). Opened up the Mercontrol and kind of reset and put it back together. At some point I started getting some movement, but it was still virtually nothing (dizzy maybe spinning 1/2").

At this point I just decided to adjust everything throttle related at the engine since likely the Mercontrol unit is old and tired.

I've got it really close, I adjusted the horizontal linkage going from the shift linkage to the dizzy inward, then I screwed the screw that actually contacts the throttle lever all the way in (it was mostly all the way out). I'm probably 75% throttle at this point. I can still reach my hand in and actuate the throttle lever (on the actual carbs) another 3/4-1".

What else can I adjust? I noticed right above the return spring on the dizzy there's a yellow collar that the throttle lever contact screw sits on. It's slotted to be able to adjust left and right. It's almost all the way adjusted to the left right now (rear of the engine).


So I believe the underlying problem is a combination of a worn Mercontrol unit (would love to replace it with something newer if I knew what would interchange - obviously I love everything vintage but would rather a modern design that works better), and old crusty grease not allowing the dizzy to actuate as easily as it should (hopefully the new grease and some water time will help).

 

[racerone]

Note-------Motor should be running or prop should be turned when shifting from NEUTRAL to REVERSE.

 

[Snatchymanx]

Noted. Had this issue when it was running.

 

[Snatchymanx]

Mercury 65hp no throttle response

Long story short, new cables (old were seized and very stiff). I had the same throttle issue before the cable replacement, only thing that changed was gear shifting is now very smooth and easy.

I have virtually no throttle. I can lay the throttle lever all the way forward and it barely even engages the throttle lever above the carbs and not until almost the very end of the throw. It moves in and out of gear flawlessly, and I get full RPM when revving it by hand and linkage disconnected.

I already ordered a new throttle cam plate and the plastic bushings. I'm assuming it's 100% in my Mercontrol unit at this point. Just wondering if there is anything else I can check?

 

[Texasmark]

At the engine end, did you position the brass barrels that set the internal travel distance under the engine cowling in the same place as was on the old cables? That's the only thing on the engine end that could cause you a problem unless the center conductor of the new cable was restricted....the center cable wouldn't move as far out one end or the other of the sheath.

Do this: Hook the throttle cable to the engine if not already connected. With the throttle cable in your hand, not attached to the remote housing, grasp the sheath in one hand and with a pair pliers, pull on the center conductor and see if the throttle in the engine moves full range to WOT. If so then your assessment of the problem being in the remote housing is valid.

Soooo why the problem now? Are there obvious signs of excessive wear? I don't see any in your pictures. Did the old cable work the throttle, just with a lot of friction? When you disassembled the remote box, did you misplace a part or get something out of line? I assume you got the right cable in the right hole in the control box and connected the right cable to the right point at the engine. That control has a fast idle lever on the top does it not? Does/did it move the new throttle cable when raised?

 

[Snatchymanx]

I traded a cheap handgun for the Starcraft a few weeks ago. As I mentioned the cables were original (1969) and seized for the most part, but it had the same issue with the old cables.

Pretty easy to adjust on the engine end. Set the throttle arm against the idle stop then adjust the barrel until it fits in the slot and cable fits over the rod.

Engine side isnt my problem I don’t think. I can move the throttle lever probably 8-9 o clock before the throttle even starts to move, and at full forward on the control the screw is just barely touching the throttle plate on the carbs. I’m only getting like 1/8 throttle.

 

[Snatchymanx]

To be clear the throttle lever is moving perfectly in and out of gear after the cable replacement. It just isn’t moving the throttle cable nearly far enough.

 

[Snatchymanx]

Am I correct in assuming that I can adjust the linkage from the throttle arm going to the dizzy (horizontal arm) and the contact screw on the backside to get more contact with the throttle plate on the carb?

Im not touching the timing at all.

 

[GA_Boater]

Am I correct in assuming that I can adjust the linkage from the throttle arm going to the dizzy (horizontal arm) and the contact screw on the backside to get more contact with the throttle plate on the carb?

Im not touching the timing at all.

In your first post you did say you messed with the timing;

I've got it really close, I adjusted the horizontal linkage going from the shift linkage to the dizzy inward, then I screwed the screw that actually contacts the throttle lever all the way in (it was mostly all the way out). I'm probably 75% throttle at this point. I can still reach my hand in and actuate the throttle lever (on the actual carbs) another 3/4-1".

Both the throttle lever rod and screws are for timing.

BTW - Merged your latest thread into the original because you are working on the same problem in both threads.

When you are trying to advance the throttle on the remote, does the warm up lever raise? And is the warmup lever fully down?

 

[Snatchymanx]

I can run the throttle lever up all the way and the fast idle lever moves up maybe 1/2”.

we took the boat out yesterday and I had to use the fast idle lever to even actuate the throttle as the main throttle lever was doing nothing.

Ive already adjusted the linkage back to what it was prior (no telling if it was even properly adjusted before I bought it). I haven’t put a light on it yet to check either. But it runs amazing actuating the throttle by hand (and gets full travel/throttle). Short of that I’m out of adjustments. Even with the fast idle cable barrel adjusted all the way up its not getting anywhere close to full throttle. That’s why I’m thinking it’s in the Mercontrol box.

They are the Teleflex 600A cables and look exactly like what came off it.

 

[GA_Boater]

Hold the warmup lever down and try full throttle. If it lifts at all, it fouls the throttle action.

The are a couple of springs and a plastic detent pin that holds the warmup lever from moving when the throttle lever is moved. The detent pin is probably broken.

 

[Snatchymanx]

The spring and pin that hold the warm up lever down are broken. They blew through the backside of the box. In fact when I bought the boat the spring was sticking out the back and wouldn't allow the warm up lever to even lay down fully. I do remember actuating it today and the fast idle lever only moved up maybe 1/4-1/2". Not sure if that would be enough for it to come out of the inner cam gear.

ill try manually holding it down tomorrow morning but I don’t think it will make a difference. I could see how the roller could come out of the track if this happens though.

I have a '69 Jupiter! Love these old aluminum boats!

 

[GA_Boater]

The action you're describing is exactly what happens when the detent pin is broken. The warmup lever binds the throttle if it isn't down all the way.

Also the warmup lever doesn't give full throttle, only about 50%.

 

[Snatchymanx]

This is full throttle with the lever as far forward as it will go. Butterfly on the carbs still has another 1/2” travel before WOT. Honestly it seems to get better the more and more I actuate it after greasing everything and actually using it. Boat sat for a long time before I acquired it.

It's immensely better than the other day on the water. I was barely getting anything above idle.

Hoping those bushings and throttle cam help with the slack. If not, new parts never hurt.

 

[Texasmark]

Engine runs fantastic, it's a 1969 65hp. I'm an aviation tech by trade, dipping my feet into the outboard world.

From the day I got it the throttle was odd. There was so much resistance going from full throttle FWD back to N and R, and the gear level/throttle cable wasn't even actuating the throttle. I put new Teleflex cables in it and we took it out on it's maiden voyage today.

Shifts great after the cables, yet still no throttle with the main lever. I could only use the fast idle lever to get it to really move in the water and it was balls slow. Went back to dock 2-3 times and kept adjusting the cable until I ran out of threads and it was immensely better but not 'right'.

D/C'd both cables and my brother drove while I sat on the back and actuated the throttle lever manually. Holy sh*t, thing hauled balls and sounded amazing (confirmed it was not carb related). We loaded it back up and went back to the house.

Dug out all the old hard grease around the dizzy and pumped in fresh grease. Still couldn't get the throttle lever to actually control the throttle, it was just gear then nothing all the way down (however, it would actuate the throttle in reverse). Opened up the Mercontrol and kind of reset and put it back together. At some point I started getting some movement, but it was still virtually nothing (dizzy maybe spinning 1/2").

At this point I just decided to adjust everything throttle related at the engine since likely the Mercontrol unit is old and tired.

I've got it really close, I adjusted the horizontal linkage going from the shift linkage to the dizzy inward, then I screwed the screw that actually contacts the throttle lever all the way in (it was mostly all the way out). I'm probably 75% throttle at this point. I can still reach my hand in and actuate the throttle lever (on the actual carbs) another 3/4-1".

What else can I adjust? I noticed right above the return spring on the dizzy there's a yellow collar that the throttle lever contact screw sits on. It's slotted to be able to adjust left and right. It's almost all the way adjusted to the left right now (rear of the engine).


So I believe the underlying problem is a combination of a worn Mercontrol unit (would love to replace it with something newer if I knew what would interchange - obviously I love everything vintage but would rather a modern design that works better), and old crusty grease not allowing the dizzy to actuate as easily as it should (hopefully the new grease and some water time will help).

As we all know grease is nothing more than oil suspended in a soap with the soap serving the purpose of keeping the oil where you put it. I had similar problems in old farm machinery and using things like penetrating oil (PB Blaster to name an effective, popularly available aerosol) sprayed into the area of concern, and working the mechanics to get it distributed throughout will loosen the "cake", then following up with White Lithium aerosol...also popularly available at WW or any auto parts store.

 

[Snatchymanx]

Ive replaced everything inside the Mercontrol
box at this point that I thought might be causing my issues (cam gear, cables, bushingu, and the heart shaped cam thing)

I’m only getting maybe half throttle (at least 1” of travel still left on the throttle plate), and have a massive dead spot on the throttle arm. 99% of my half throttle is at the very end of the throw in forward gear. I do not have this issue in reverse.

Im assuming the issue now lies at the engine itself.

How I adjusted the new cables (it had this problem with the original cables as well)


-Put engine in neutral adjust barrel until it falls in slot and hooks up to the gear selector
-Push throttle arm up against idle stop and adjust barrel until it falls in slot and bolts up to the throttle arm.

I can throttle it all the way up by hand with the cables removed, so im not quite sure what else it could be. I’m ready to throw this Mercontrol in the trash and replace it with something newer and more reliable.

 

[Texasmark]

Ive replaced everything inside the Mercontrol
box at this point that I thought might be causing my issues (cam gear, cables, bushingu, and the heart shaped cam thing)

I’m only getting maybe half throttle (at least 1” of travel still left on the throttle plate), and have a massive dead spot on the throttle arm. 99% of my half throttle is at the very end of the throw in forward gear. I do not have this issue in reverse.

Im assuming the issue now lies at the engine itself.

How I adjusted the new cables (it had this problem with the original cables as well)


-Put engine in neutral adjust barrel until it falls in slot and hooks up to the gear selector
-Push throttle arm up against idle stop and adjust barrel until it falls in slot and bolts up to the throttle arm.

I can throttle it all the way up by hand with the cables removed, so im not quite sure what else it could be. I’m ready to throw this Mercontrol in the trash and replace it with something newer and more reliable.

That's not as complicated as you might think. The Commander 2000 is a direct replacement for the outside, bulkhead mounted control, and last time I bought box and wiring harness it was right at $250 right here on iboats. I never looked back. Just get the one with the correct number of pins to fit your engine.

 

[Snatchymanx]

I can use my Teleflex cables with it?

 

[Texasmark]

I can use my Teleflex cables with it?

If you have cables that are already operating your engine and running a Mercury/Quicksilver control currently, yes you can. The Commander box uses a solid, threaded outer brass hollow rod with the familiar brass "barrel" that is moved up and down the length for adjustment just as is in the engine. The center has the hole as does the engine.

Edit. Just remembered I use Teleflex cables in my boats. Nice suppler, very customer oriented.

 

[Snatchymanx]

Yeah my cables are brand new and my motor is a 6 pin so I would definitely have to do some rewiring