need to replace control cable for transmission

[bugbitten]

Since my boat has been back in the water, I've found it very hard to move the engine's control lever with the transmission in gear. I finally checked the transmission's control cable and it appears the PO had damaged the housing at some point and covered it with electrical tape. It worked fine for the first five years I had the boat, but no more. I've not found much on a specific replacement cable, but other forums have mentioned that the SeaStar Solutions universal 33C Red Jacket control cables will do the job. It certainly looks identical to what's in there. I measured it and came up with a ten foot length. Will I be ordering the right thing?

Thanks.

John

 

[Mark Maulden]

Not familiar with Sea star...Teleflex makes a variety of cables. Have you disconnected the cable from the gearbox and try to move it? Hopefully, its just the cable and not something in the gearbox....

 

[Dave Groshong]

I don't have data for the length for your boat, but we have the cables here:
http://shop.hunterowners.com/prod.php?7716

 

[bugbitten]

Not familiar with Sea star...Teleflex makes a variety of cables. Have you disconnected the cable from the gearbox and try to move it? Hopefully, its just the cable and not something in the gearbox....

It's a NEW gearbox, so I sure hope that's not it! I can shift the gearbox easily by hand, and the cable is cheap, so I'm starting there.

John

 

[bugbitten]

I don't have data for the length for your boat, but we have the cables here:
http://shop.hunterowners.com/prod.php?7716

Thanks, Dave. I did check your shop and had only seen the larger cables, not this one with the 10/32 ends. I'll order the 10 footer from you today.
John

 

[bugbitten]

Oh, and I did remember to put fluid in the new transmission before I started using it! The old cable's housing definitely has some issues and predates my ownership of over six years, so replacing it is a good idea. I'd already replaced the shut off cable. I'll probably do the throttle cable, just so they're all fresh. To tell you the truth, I really don't like the single-lever engine control and may keep my eyes out for a good, used dual-lever unit.

John

 

[bugbitten]

I ordered and received very promptly the control cable from SBO's shop. Took just a couple of days, which is pretty darned good considering it went from west to east coast. It fits perfectly, but I'm having issues getting the two cables to work properly. The transmission now goes in and out of gear, forward and reverse, much more easily, but I'm only able to move the throttle, in reverse, to about 1500 rpm, where I could hit 3K easily before the switch. I didn't think I'd done anything to the throttle cable. I'm taking the Yanmar manual with me to the boat this morning, and expect to spend some hours in the big cockpit locker, trying to puzzle it out. I'd sure like to get a sail in before we have to start hunkering down for Irma.

John
Newport News, VA

 

[jviss]

That's interesting. I wonder if it wasn't shifting all the way into reverse with the old cable, and it was slipping to allow full speed. It seems to me more likely that you did something to the speed cable or linkage by accident.

Does it rev to 3k in forward and neutral? What kind of prop?

 

[bugbitten]

It has a new, Flex-O-Fold, two blade, folding prop. I've not been able to get more than 2600 RPM in forward (when I could easily get more than that with the old prop), but could hit maybe 3200 (accidentally - it was surprisingly smooth) in reverse. The engine was out due to lots of major alignment work, and the mechanic reconnected the cables. As I said, now I'm getting 2600 forward and only 1500 in reverse. I'm going to reset the transmission cable connection at the transmission, to make sure it's centered in neutral. Then I'll see if there's still an issue. I'll also look at the throttle connection at the engine, but I find the instructions in the manual a bit confusing. I may have to come back tomorrow with a protractor, but tomorrow looks to be a great day for sailing!

 

[jviss]

I don't know, maybe other Flex-O-Fold owners might comment; maybe the pitch is different in reverse than forward? Maybe that time you got 3200, the prop didn't unfold? But yes, check the speed linkage. You should be able to disconnect the cable and move the speed control through its range manually. (I hate to say "throttle" for a diesel, as it doesn't have a throttle, it has a speed control. The cable connects to the control for the governor, and the governor keeps the engine speed constant regardless of load, to the limit of engine power).

It doesn't make a lot of sense that the max speed is different in forward and reverse, since it's the same speed control doing the same thing; unless the shift linkage is interfering with it, or the prop load is different.

 

[bugbitten]

I readjusted the transmission control cable to better center things when in neutral. I am now able to fully move the control lever (single lever for both engine speed and transmission) in forward and reverse. It looks like the same amount of "throttle" travel in either direction. I'm now getting about 2700 RPM in forward, but 3400 in reverse! I'll email Flex-o-fold; maybe it's just how this prop works. Sure wish I could hit 3K in forward, though. It'd be nice if I could keep it from going that fast in reverse, although the plate on the engine shows it's rated at 16 HP at 3400, so I guess it's okay.

 

[jviss]

Oh, I see, I didn't realize you had a single lever control. I am not familiar with those, but I can imagine if misadjusted you could get different speeds forward and reverse.

 

[DayDreamer41]

A prop will have different thrust characteristics in forward to reverse, forward having more bite, the differential in RPM could very well be from this design. What was your RPM before you changed prop's to the Flex-o-fold. I know on our boat the engine design states max speed to be achieved at 3400 RPM with the OEM prop, but the Flex-o-fold prop will only spin up to 3200 RPM which I attribute to the difference in pitch between the OEM and Flex-O-Fold props.
The question is are you achieving your max speed at 2700 RPM? if so it sure sounds like it may be over propped.

 

[bugbitten]

I'm hoping to get the boat out on the water tomorrow. I'll report back afterwards. Tied up at the pier (and when I had it out previously, before replacing the shift cable) 2700 was about all I could get forward, 3400 reverse. It'll certainly be disappointing if they made up the wrong prop for me. It was similar in size to the original, non-folding, two-blade prop, but the blades were somewhat broader. I bought it at least two years ago, but didn't install it until recently. I tend to stockpile project parts when I'm flush, and I had a whole ton of them to do once the boat was finally on the hard.

John

 

[jviss]

I will bet it's the linkage. Who makes it? Do you have a manual for it?

 

[bugbitten]

My understanding of diesels is very limited, but the engine speed control cable, when moved as far as it will go, moves the speed control lever on the engine what sure seems to be the same distance. It's a Yanmar 2GM20F, rated at 16 HP @ 3400 RPM. One lever controls both the speed and shift cables. The speed cable is the same one that was on the boat when I bought it over six years ago. It moves smoothly and doesn't have the damaged housing the shift control cable did. It was disconnected when the engine was lifted to put in new mounts, etc., but, given the way it connects, I don't think any big changes were made. I'll upload a picture of the back of the control unit, showing the cable connections, and a picture of where the speed control connects to the engine, with the control lever moved to its highest speed. The distance from the idle stop to the crook in the lever on the engine was about 2.5 centimeters, whether full speed ahead or astern. Not great snaps, but the best I've got at the moment.

John

 

[jviss]

Some marine gears have different gear ratios for reverse than for forward. That might partially explain it.

 

[DayDreamer41]

The linkage on ours is by Lewmar and looks very similar to the picture. If the engine control cable at the engine end is moving equally in both directions of lever travel then I doubt very much it would be linkage.

 

[bugbitten]

I agree, darn it.

 

[bugbitten]

Some marine gears have different gear ratios for reverse than for forward. That might partially explain it.

That could be, but, again, the speed cable seems to move the same amount either way. Of course, it could be a millimeter or two different and hard to detect.

BTW I just noticed that the photo of the back of the control unit was a before shot, with the original cables. I may take an after one tomorrow, but I don't think you'll see any difference, other than the new shift cable's housing is black. I had this RPM difference before the cable swap, anyway.

John