Throttle cable woes :(

[Ken Palmer]

The throttle adjust on our 1990 H33.5 is very difficult to advance. Yesterday I tore the boat apart to follow the cable path, expecting to find a clamp that was too tight. I found no clamp. I disconnected the cable from the engine and still had resistance. I opened up the steering pedestal and the only thing there was a hex head screw at the hole through the binnacle where the throttle shaft exits.My observation is that both cables take some extreme bends getting back to the engine. I wonder if it would solve my problem just replacing the cable, or should I look at alternatives to re-route the cable in a more direct path to the engine (if possible). The shift cable is run the same path, and shifts fairly easy.Any ideas out there?Ken Palmer, S/V Water Colors

 

[Paul Akers]

Sounds like time to replace the cable

Cables lose their lubricity over time. If it has been had to throtle for some time, then I would think there is also wear within the sheath. But you could try to get some penetrating oil into the shift cable somehow. But it may be time to replace it, now. If it breaks on you (like it once did to me) then you may be stranded. If you replace the throttle cable, then you should replace the shift cable, too. Since you will have things torn apart.

 

[Debo Cox]

Drag adjustment maybe?

Hi Ken,I recently have been working out throttle issues of my own, so I'll throw in my 2 cents worth. You mentioned a hex screw at the binnacle, and that the drag was still present after disconnecting the cable from the engine.Most throttle controls have a drag adjustment to counteract the tendency for the engine to back the throttle down by itself. Sounds from the description that your drag screw may be set a little tight. Not knowing your setup, it's just a guess, but on my older Edson pedestal control, there was a drag adjustment screw inside - where the cable connects to the linkage.There's so much variability with these things that it's difficult to pinpoint the problem exactly without seeing it, but check your drag screw.

 

[WindDance]

Loosen that hex screw...

The hex head screw you see in the pedestal on the throttle shaft is there to provide a drag to oppose the return spring pressure on the throttle lever on the engine. Make sure the lever on the engine moves freely and returns to the idle position with the cable removed. If you have a Yanmar 3gm30F engine like in my 1990 33.5, a leak from the pipe feeding the heat exchanger can drip onto the throttle lever and cause corrosion that will freeze up that part. Next, reattach the cable and adjust the hex tension screw, in the pedestal, so that you can set a throttle position and it holds there.You can check the cable freedom by moving it while datached from the engine.I've had the same problem.Good luck.Bob Belvin...

 

[Ken Palmer]

Not the hex head screw

I tested the ease of motion in the throttle cable after taking the hex head screw completely out with little change noticed. It seems that there is a point when advancing the throttle that feels like metal scraping and of course tightness during 10 to 15 percent of the full motion. Then it gets a bit easier. Same thing going from full throttle back to idle.Looking down inside the pedestal I see no further adjustment of the cable, but what looks like a possible bend in the cable as it meets the outer casing.My 33.5 has the older 2GM20F engine. I did not see any spring on the engine at the throttle lever. I did disconnect the cable with little change in the tightness.I believe a replacement is in its future, but I don't know if that is a job I can do. These old body parts have a difficult time getting into tight places.Ken Palmer, s/v Water Colors

 

[Paul Akers]

A note on throttle lever

As noted, the throttle lever on the engine is spring-loaded. You cannot see the spring since it is internal. The engine throttle lever should return to the full low throttle position when you advance it manually (cable disconnected). If it is tight, spray it with a penetrating oil such as PB Blaster (available at auto stores) and let it sit for a few hours for it to work. When it loosens up, spray it again with spray lithium grease to water-proof it from that heinous drip from the heat exchanger connection to the raw water hose, where is sometimes drips.

 

[Gary Wyngarden]

Cable Problems

Hi Ken,When I owned my 33.5, the only throttle cable problems I had occurred where the cable exited the sleeve at the point of the engine attachment. The clamp would loosen from the vibration and the cable would jam.On my 37.5 I replaced both cables (throttle and gear shift) this year because one broke. I was surprised to find a sleeve at the bottom of the steering pedestal with a small cutout on the side that the cables passed through. It appears the function of the sleeve is to keep the cables to the side of the pedestal so they don't foul on the chain. I don't remember if the 33.5 has this arrangement, but I guess it's possible your throttle cable isn't passing cleanly through the cutout? Hope this helps.Gary WyngardenS/V Wanderlust 37.5

 

[RJ9757]

I replaced my throttle cable recently....

I had the same symptoms, and was dreading the job... but it wasn't that bad, really. Barb, the Yanmar expert over in Oakland, actually recommended a Volvo cable, saying that it was more flexible. Anyway, on my H31, it was a 10' cable, routed down the pedistal, through the top of the quarterberth, through the starboard lazarette, and into the engine compartment. I disassembled the top part of the binnacle, wired the new cable to the end of the old cable, and had a friend pull the cable forward from the engine as I nursed both cables through the circuitous path from the binnacle to the engine. The new cable solved all my problems, and I suppose it should last another 15 years or so. PS - I wouldn't necessarily change the shift cable, as it gets a lot less use, but I got a spare, just in case.Hope this helps. Rick J

 

[Ken Palmer]

How about lubrication?

Thanks for the advise. I wonder if anybody has tried lubricating the cable. I think it is binding up in the pedestal and was thinking of a drop of oil there. Perhaps there is a better lubricant than oil?If all else fails, maybe I'll try to replace this fall.

 

[mtc4180]

Troubleshooting

If you can, get your hands on the replacement cable, replicate as closely as possible the bends your installed cable makes and see how the replacement cable moves. This way, you can easily rule-out the routing issue you mentioned. 1. If the replacement has the same resistance, then its not routing and you just saved yourself some time and money. 2. If the replacement is much easier, then you've identifed some of the tension.Good luck - Michael

 

[Bruce10490]

Same symptoms

Hi KenMy 1991 is exactly the same. I believe the cause is from the ridiculous bends the cables have been subject to. I will be waiting to see if you find anything else.

 

[RJ9757]

Circuitous route,,,

Regarding my earlier post, dealing with replacement of the cable on my H31, I, too, found the routing of the throttle cable to be mindlessly tortuous... however I was replacing the cable with a new one of the same length, so I followed the original path. I eased some of the angles, but the main point is that, following the original route, the new cable was extremely easy to operate. I considered the same things you mentioned, e.g. lubrication, but since the cable was 10' long, and sealed at both ends, I couldn't figure out a way to lubricate it along it's entire length. I really think that attaching the new cable to the end of the old one and pulling it through the original route, with someone lending a helping hand to feed the cable through the tough spots as the cable goes between compartments was the best solution.

 

[Ken Palmer]

Source of new cable?

OK, you guys have convinced me that it isn't as difficult as it may appear and that I can do it myself with a helper. Now I need to estimate a length and buy a replacement cable. While visiting the Edson website, I noticed they sell cables. Are they all alike or should I buy a known name like Edson?

 

[RJ9757]

teleflex push-pull cable?

I assume that it's a standard teleflex push-pull cable... and, although I'm certainly not an expert, I know that there are several manufacturers, and most products are probably fairly comparable. As noted earlier, the marine diesel parts gal in my area recommended a Volvo cable, indicating that it was more flexible than the original one that came with the Yanmar. Call Barb at 510 465 1093 and she could tell you what you need and ship it to you, or maybe give you a point of contact in your area, as there seems to be some wierd territoriality when ordering marine parts sometimes. Anyway, good luck - Rick J

 

[Ken Palmer]

Thanks Rick J

I will give Barb a call on Monday. I'll keep you posted.