# Yanmar 3GM woes



## TSOJOURNER (Dec 16, 1999)

Well, it finally happened.. I got an a list of all the things that my current boat yard thinks is wrong with the mechanicals on my (very new to me) old boat. For some background, the 1993 Yanmar 3GM30 was rebuilt in '05 and didn't have any hours on it until August 2007.. it probably got all of 20 or 30 hours until we hauled her out in Oct.. Over the summer, other than one blown solenoid which presented a starting problem, the engine worked fine, started when it was supposed to, and ran smoothly. The shifter is a little finicky and needs adjusting - it would cause a less-than-smooth shift, but nothing that seemed horribly damaging to me (what do I know?!)... I was never maneuvering in tight quarters so never had a need to shift hard or quickly, so I pretty much babied it.

Given the yard's really horrible attention to detail and poor workmanship over the winter I'm a little hesitate with them.. but then, what can I do? The boat is stuck in their yard. I've listed the items they've come up with below. My three questions are: 

Does anything look particularly over-priced?

Are any of these things I could manage doing myself? (I am a reasonably competent avg. joe, but no mechanic, and with limited tools.. but it seems like I could, for example, replace battery wires easily enough. Am I kidding myself?)

Is it worth putting all this work into such an old engine? (I know this is somewhat subjective..) 

1. The stop cable is frozen up solid from corrosion and needs
replacement.
$25.40 Parts
$105.00 Labor
Total $130.40

2. Rebuild of Kanzaki Gear KM3P
Rebuilt Gear and new dampener plate $1,306.99
Labor $560.00
Total $1,866.99

3. Replace engine wiring harness and New B type Panel
Parts $607.60
Labor $420.00
Total $1,027.60

4. I know you and I had discussed the replacement of the battery cables
and after further investigation it will cost more than I had originally thought.
Parts $250.00
Labor $420.00
Total $670.00

5. We looked at the shifter issue and we need to relieve the stringer
to allow for proper throw of the shift lever on the transmission. The
shifter itself will have to be repaired as well but it is difficult to get
part's for that shifter. We will try to repair this one or we will give you a 
replacement price when we get there. This will be a time and materials
job!


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## Rockter (Sep 11, 2006)

Stop cable.... cost £50, time to fit... 20 minutes.... $105 labour ????
Wiring harness... cost ??, time to fit.... maybe one full day.... faster with help.
Battery cables.... cables maybe £50, ends maybe £20 and time to fit, maybe a morning (buy the crimping tool, or hire it). labout $420 !!!!! ?????????

Until you fit the stop cable, just stop the motor by hand. Reach in and pull it.

Do not play this game with this yard. You are about to get savaged. These prices are savage... savage... savage.

Tell them to f**k off.

Brit... I cannot speak for the gearbox, but PM me and I will steer you through the battery cables and the stop kill line... they are both absolute gifts to the semi-intelligent man. I will give you some decent pointers for the wiring harness. Do you REALLY need a new harness. What's truly wrong with the old one???

Pull the gearbox off, and get another one with some life in it. Taking a gearbox off would take a morning. It is not difficult to put it on again, even if the motor is still in the boat it is not difficult. I have done it for the Volvo MD17C. Once you have done it once, it's a gift, if slow. 

Rockter.


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## JohnRPollard (Mar 26, 2007)

Regarding your question as to whether the engine is too old to invest this money in, I would answer "NO". That's a '93 engine with an '05 rebuild and low subsequent hours. We have the same engine, 1990, still original with no rebuild. I wouldn't hesitate to repair the items you listed (assuming they truly need replacement.) 

A reasonably competent DIY person should be able to handle most of these, except maybe the transmission rebuild. 

But what makes you think you need a new panel? Is there something wrong with the old one, that can't be fixed?

Also, why a transmission rebuild? I would start by replacing/adjusting the cable linkage and see if that fixes the shifting problem. 

If you can't do these jobs yourself, and you are not happy with the yard's work thus far on other projects, you might be better to bring it elsewhere for the engine work, or bring an outside contractor in.


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## danielgoldberg (Feb 9, 2008)

Sadly, these prices don't seem excessive to me. I'm not sure what the labor rate is in Maine, but here in the NY/LIS area, skilled labor bills out at more than $100/hour, hovering around $125 for people in demand. Just from the numbers it looks like your yard bills out at $105. So, for instance, they are estimating that the stop cable will take an hour to fix. That doesn't seem excessive to me. 

Can't tell whether you actually need this work, so can't comment on that. Likewise, the parts numbers also don't seem crazy.

I bet the battery wiring is something you can do, though I would pay to have the cables cut to lenght and crimped with the proper fittings. Battery cables are not the easiest to work with if you lack experience, and that money will be well spent. Just curious, why do you need new cables? Those don't tend to go bad absent something unusual.

Something else to keep in mind is that these are likely just estimates, which means if a project takes longer than anticipated it will cost more (though in theory the reverse is true too, nothing ever takes less time than expected when you're paying by the hour).


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## Rockter (Sep 11, 2006)

The only truly skilled part of the list is the gearbox re-build. The rest can be done by anyone with enthusiasm.
Is there no such thing as a second-hand gearbox? They are normally very reliable and last a very long time, as they run in ideal conditions in an oil bath.
That total bill is like $3700.... yeeeeaaaarrrrggghhh.
That would breed enthusiasm in anyone.


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## camaraderie (May 22, 2002)

I don't see anything unusual with the prices being quoted for the work anticipated. Fairly normal yard prices here I'm afraid. 
As Rock says...a lot of this work is not particularly skilled and could be done on a DIY basis since you are paying $100 bucks and hour for labor...
Example...you could buy ancor battery cable and have any auto shop swage on connectors cheaply and then run the cables yourself. It is all a matter of how involved you feel you can get and what your own time is worth. But the actual engine is not a factor in any of this so I don't know why you call it 3GM woes...it is all stuff that connects to the engine that needs re-doing! Stick with it...good engine!


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## jrd22 (Nov 14, 2000)

The engine should be in excellent shape with 30 hrs. on a rebuild, don't know how many hours are on the trans. so can't comment about that. The stop cable is a ridiculously easy job, anyone should be able to do it. The shift cable issue sounds like all you need to do is cut away some wood to allow more throw, I'd bet the shifter is fine. The battery cables while being fairly straightforward can be time consuming depending on where they are run, access, etc. While I don't see their estimates as unusual or excessive (normal rip off boat yard prices), you could save a lot of money doing it yourself. The wiring harness has me baffled; are you having trouble with it or did it short out? Is the harness not available without going to the new panel? Is your panel damaged? Not sure why they are suggesting replacement, and it is a fairly easy job depending on where it has to run.

John


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## Faster (Sep 13, 2005)

I'd have to agree that most of these jobs are ones we'd tackle ourselves...

And I'd want some pretty good evidence that the tranny was truly on deaths' door before going to that expense and inconvenience. Ditto the harness... it's be interesting to hear the rationale for that one.


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## brak (Jan 5, 2007)

Check your RPM before doing anything else to the transmission. Idle RPM being a bit high would cause a jerky in-out of gear, this is what happened on my engine - the adjustment of gas cable was slightly off and it idled at about 1200. Every switch of a gear was a loud boom, shuddered the boat. Adjusted the cable so that idle RPM went down to about 800 and voila - all works well.

Yanmars are good engines and run for a long time unless greedy yard trolls get their hands on it. Get a second opinion.


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## paulk (Jun 2, 2000)

We have a 1983 raw-water cooled 3GM on our boat, so we've had to do some things to keep it running. We've replaced the hoses. It's not a big deal, but it helps keep the engine happier. We had to replace the stop cable too. Have you ever adjusted the brake cables on your 10-speed? this is the same thing, but longer. Use the old cable to pull the new one through. I believe they tend to come in standard lengths, so The summer before last we added an inverter to our electrical system. One big enough to run a hair dryer, so it entailed running twenty foot wires the size of battery cables through the bilge and to the battery switch and inverter. We could have had "the man" do this for us at rates like those you're quoting. Instead, I spent two hours on the boat instead of four hours working to pay for what I'd probably have been charged. If you're simply replacing the cables- guess what? You remove the old ones, take them to an electrical or automotive shop that can copy the length and gauge, and you put the new ones back on. If it involves leading them through tight spaces, tie a light but strong line to an end before you pull it out, and leave the line in place so that you can pull the new cables through. Why are you changing the wiring harness if it still works? We haven't had to mess with the transmission, but then again, we tend to sail more than we motor. 
From what you say about having the thing rebuilt so recently and not having any real problems, it makes it seem like your yard is out on a phishing expedition. I would go somewhere else after you're launched and get a second (or third) opinion before having anyone (including myself) do anything to it.


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## Rockter (Sep 11, 2006)

Brit...

Unless it is spent, leave the harness. Mine's into its 31st year. Just leave it if it works. Sure, check it for chafe at the rubbing points, and tape it generously where it does rub, or use some chafe tubes, but leave it otherwise.

The only job that appears to be pressing is the transmission, and I am not sure that the transmission is spent. If you take some pictures of the trans and the final drive, I would be very happy to do my best to talk you through it. I have been there with the Volvo, back in 1997, and it is not too bad. Oh, I like transmissions... oh yum!

Oh, and you Americans must stop calling it a "tranny", you must call it a "transmission", or a "trans". A "tranny" is a man that dresses like a woman... you know, shaved legs and handbag and lipstick and stuff ....and it's nothing to do with Yanmar.

Rockter.


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## camaraderie (May 22, 2002)

Rock...re: Tranny's...we call those GIU's here!


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## jrd22 (Nov 14, 2000)

Rockter- tranny is common terminology for transmission here, but from now on I will have a different picture in my mind when one of my mechanics tells me we need to "pull the tranny, look into the tranny, strip the tranny down, etc". They're going to wonder why I have an odd look on my face. 

John


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## TSOJOURNER (Dec 16, 1999)

*Some more information*

Thank you all for very useful information!!

Let me clear some things up:

1) I did not mean to disparage the 3GM by labeling the thread "3GM woes" - just meant to indicate the problems are mechanical/electrical surrounding the engine.

2) I used the boat from late July through Oct. with no problems whatsoever (20 or 30hrs on engine - I mostly sail too). The shifter has acted up on occasion and may need a rebuild or replacement - the middle nob that allows one to pull it out (in order to rev the engine in neutral) or push it in (allow shifting to occur) is finicky, but this has not affected the engine itself. The shifts have a slight "clunk" to them, but nothing even close to what Brak mentions - I always pause in neutral, as well, and never do a hard shift from forward to reverse (or vice-versa). It has always idled at 800 without any problems.

3) This particular boat yard is in the $85/hr range, as of last summer. They have never given me good information as to WHY something might need replacement, just that it does. The battery cables are "worn out," the wiring harness is "haphazard" (really, they used that term!). I haven't had any problems with the wiring harness myself, other than the connector (between harness and panel) slips out sometimes, resulting in the RPM gauge not working - I just reach down and re-plug and things work again. This should be fixable with some electrical tape, as far as I can see.

4) I thought most of these things sounded easy enough - battery cables? How hard could that be? My batteries sit right next to the engine, behind the battery switch in the main cabin. There is probably no more than 3~4ft. of cable, total, with no tight spots to thread them through.

5) The panel itself is just old and missing some functionality (no key!).. I really do not care that there is no key for the engine. The RPM gauge works and the indicator lights all work (overheat, etc).

6) The gear box rebuild was put on the list of things that need to be done that I received via email from the boat yard. I have not been given any explanation or reason for this to be done. As I said before, the engine seems to have been running fine last summer and I didn't notice anything out of sorts with the transmission.. though I have limited experience with marine diesels.

I am going to try to contact the mechanic who rebuilt the engine in '05 to get his take on all of this. Perhaps he'll have some opinions. I'll attempt to tackle most of the smaller things this month myself. As far as the transmission, I may get a second opinion.

Rockter: This may be a horribly uneducated question, but can you remove the transmission while the boat is in the water? If not, this might be something I have to have the yard do anyway, since it'll cost more to get it to another yard than it will to have them rip me off.

Thanks again, all, for assuaging my fears (or, rather, confirming my suspicions about the nature of my boat yard)!


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## Rockter (Sep 11, 2006)

Britcoal...

Reading you last post, I think you have been a potential victim of the hard sell, planned to make you $3800 poorer.
So the motor will shift OK if you change slowly??? What's wrong with it then, apart from a wee "clunk"? My gearbox clunks, but changes fine and has done OK for years.
My wiring is certainly "haphazard", as I have added an audible alarm (BMW relay and automobile horn), Ample Power 3-step regulator and Ample Power 100 A alternator, and, believe this, the Volvo RPM and temp indicator drops out if I wiggle the blocks behind the panel!!!! I know why it does it, too... the wires and blocks are a bit tired.... but I would never dream of changing out the loom to cure that one!!!!

I beg of you there Brit, get your digital camera and take picture after picture of the engine, gearbox (lots of that one) and the battery leads and alternator and such stuff and post them on here. I reckon I can talk you out of nearly all (if not all) of this hard sell.

I will tell you how to get the gearbox out of there too, if you want to, once I see a picture. Generally you take off the final drive coupling (sometimes you have to grind the bolts off if it's a-rusted... ($30 grinder, a few grinding wheels, a set of goggles $10 and ear defenders $10), then push the prop shaft aft a little to gain clearance. Then dismount the cables... there will be 3 of them... kill line, throttle and gearshift cables.
Now drain the gearbox oil (I use one of those sucker pumps through the dipstick).
Then identify the bolts that hold the 'box to the engine proper (on the Volvo there are 4 of them). Back them out a little slowly, and you may see a wee gap opening up (often not). If not, back them all out and store them. Now lean a LITTLE on the gearbox and rock it from side to side. If it does not co-operate, then tap it with a heavy mallet as you rock it. keep a good hold of the 'box as if often suddenly will come away. 
If it does suddenly come away, have a friend watch for big shims that may drop onto the bilge (mine's a deep bilge... "the pit" as it is known... my Great Uncle is still down there somewhere).
Keep the job well-lit... lots of light.

I don't think you need to take it off if it's getting the gears OK. That's all it needs to do. Often a clunky box is improved by lubing the cables a wee bit. WD40 is the finest lube for cables I know, and that's 32 years on.

Is there a website with an exploded view of the 'box? Can you post it.

I say again, I don't think you need to mess with this 'box !!!! The only time I ever took the 'box off was when it was slinging oil everywhere out of the final drive seal. We solved it in the end. It is still holding oil, 11 years on.

Brit, where this leaves you is knowing how your ship is wired, how your battery cables are routed, how the gearbox goes on, and off, and leaves you with all the tools, vital experience and about $3500 better off.

Don't co-operate with this boat yard there Brit, without HARD evidence of this stuff being needed. Even then, do it yourself.

Post some pictures for a start.

Stay away from cheque-books, invoices, bills and boat yards right now. You are about to get ripped if you don't.


Rockter.


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## Rockter (Sep 11, 2006)

Brit...

PM me if you want.

Rockter.


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## TSOJOURNER (Dec 16, 1999)

Rockter: Thanks again. As I'm up here in Maine and we just had some snow spitting yesterday, the boat is still winterized and covered. In the next few weeks I'll be opening her up for spring and I will be absolutely sure to take many pictures and report back here with any and all info from the yard, as well. Thanks again!


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## Rockter (Sep 11, 2006)

Does the motor and gearbox look a bit like this one?...

Offshore Marine Dealers for Yamaha Outboard Marine, Boston Whaler, Caribe and Inflatable boats in St. Thomas, Virgin Islands


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## theartfuldodger (Sep 4, 2006)

I would suggest you call a Yanmar Dealer and get a second opinion, as they know their stuff, and will give you a better picture. I also am sure their rates might be a little less. One thing sometimes some marina's don't permit off property trades permission to work in their yards.


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## sailingdog (Mar 19, 2006)

Given what has been posted here.... I would agree that Britcoal is being pressured into doing a lot of work that is relatively easy for him to do himself.


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## Faster (Sep 13, 2005)

sailingdog said:


> Given what has been posted here.... I would agree that Britcoal is being pressured into doing a lot of work that is relatively easy for him to do himself.


... or even worse, unnecessary to begin with


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## TSOJOURNER (Dec 16, 1999)

Faster said:


> ... or even worse, unnecessary to begin with


Which, of course, is exactly what I am afraid of. 

Rockter, the picture in that link looks a bit different from my engine (I think.. I haven't seen the boat since early January, so I don't have a good picture in my mind). My gearbox is slightly more rounded out, and less "rectangular". I believe it looks very much like this, but can't be sure: http://svhorizon.com/refit/yanmar.jpg.

As stated, I'll return with some digital photos when I get the chance.


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## Rockter (Sep 11, 2006)

Brit...

Can you see the square nameplate at the rear, just above the grille? Well, that nameplate is on the so-called "bell housing" and it is held on by 8 nuts, 6 of which you can see. The housing will come away easily, and the gearbox is bolted onto the bell housing from the inside. Again it should come away easily.... it looks like there are about 10 bolts holding that one on.

That rust-looking bit on the end is the final drive coupling flange, and all the stuff aft of that will disconnect (if it is too rusty, you grind the bolts off and buy some new bolts) allowing you to push the propshaft aft a little, and it only need be a little to allow you to lift the bell housing and gearbox away together. You will have to lift them away together as you cannot get the gearbox off the bell housing from the outside.

After that, it's all yours there Brit.

There may not be anything wrong with that gearbox there Brit. I really doubt it. I have only seen one gearbox fail among all the boats I have been around. If your 'box had oil in it, and it was changed every now and again, it really should be ok. Even if it is in trouble, you should be able to find another 'box with plenty of life in it there Brit, and it will bolt straight on.

I will help you when the time comes, but check the lubing of the cables first. Sticky cables will make a gearbox clunk like crazy, just like it does on an old motorcycle. Try disconnecting the cables completely at the gearbox and shifting the gearbox manually. All will be revealed. You may find that it will shift easily, in which case, your cables need some lubing, or replacing.

Don't be afraid of this stuff there Brit.

Rockter.


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## TSOJOURNER (Dec 16, 1999)

*More information on yanmar transmission issue*



Rockter said:


> .. check the lubing of the cables first. Sticky cables will make a gearbox clunk like crazy, just like it does on an old motorcycle. Try disconnecting the cables completely at the gearbox and shifting the gearbox manually. All will be revealed. You may find that it will shift easily, in which case, your cables need some lubing, or replacing.


Rockter - thanks again for the info. I spoke briefly (over email) with one of the yard mechanics today and he had this to say about the transmission:

"There is a delay in the transmission when it does go into gear which is most likely caused by bad clutches."

I happen to know that my shifter is finicky and could use a rebuild - it doesn't travel enough. What are the chances this has something to do with the transmission being slow to engage? (I'm guessing: a very good chance)

To be clear, I've never noticed clutch slippage at all, and the "delay" I have noticed is, quite literally, no more than a second.

I'm tempted to say screw it, and just go sail for the season. I'm probably looking at ~50hrs engine time, tops. Does anyone think that's a bad idea? I still haven't gotten up to the boat to check her out this spring, work has been busy. I'll know more when I do.

Thanks for all the help guys.


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## Faster (Sep 13, 2005)

No funny noises, no problem getting in or out of gear? Just this "delay".... I'd say go for it.

We once contacted a Hurth service guy with concerns about a bit of noise in our HV-150... and asked about a rebuild. He told us that there was no real point in doing a rebuild prior to a failure. We put many more seasons on after that, and the boat is still going strong 8-10 yrs later. YMMV.....


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## erps (Aug 2, 2006)

If it were me, I'd check the oil and run it. If you can hold your hand on the gear box without burning it and there is no excessive noise, it's most likely good to go. 

Transmissions just don't wear out like other drive train components.


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## TSOJOURNER (Dec 16, 1999)

Faster: no funny noises, no.. I truly suspect linkage problems between the shifter and the transmission, as the shifter has been giving me problems. If it is 'bad clutches', what's the worst that could happen? Perhaps it just fails to go into gear one day. So be it! I haven't had any tight navigation requirements yet, so I'd likely be able to sail out of any trouble I get myself into.. that is until I'm stuck on the wrong side of a tide in a calm...


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## Faster (Sep 13, 2005)

Whoa! You're up late!!

I really don't think you've got too much to worry about... especially if you're not heading off to places where service or help would be unavailable.

As to being on the wrong side of a tide, well that probably _is_ the time something goes (Murphy and all) but if you can't sail out you've got the anchor, right?

As I mentioned earlier, I was virtually offering the Hurth guy a couple of grand in work... so his take on things was enlightening.

Best of luck...


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## Rockter (Sep 11, 2006)

Brit...

Disconnect the cable at the shifter on the gearbox, then shift the 'box manually. If the 'box works ok and you do not have this "delay" they talk about, than the cabling and/or lever travel is the problem.

At that moment you can decide that there is nothing much wrong with your gearbox.

If it still "delays", then you can re-think. It may be quite innocent.

Does anyone have an exploded view for this gearbox?

In the meantime, make sure you start your motor and check your gearbox will engage before you are committed to it, on the approach to the dock, for example.


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## JohnRPollard (Mar 26, 2007)

Brit,

I agree with the others on this. You said the transmission was working when you winterized the boat last fall. It didn't wear out sitting on the hard unused. Get the boat back in the water, fiddle with the linkage, and see how things go for a while. In the worst case, it's not likely to fail suddenly and catastrophically. More likely, it will get progressively worse if there truly is a problem, giving you plenty of warning and time to arrange service.



Rockter said:


> Does anyone have an exploded view for this gearbox?


Rockter,

I don't know exactly which transmission Brit has. It would probably be the Kanzaki KM2P or KM3P. I couldn't find exploded views for ANY Kanzaki transmissions, though. The best I could find for you are some tech specs for the TTMC2P-1, which I believe is the current equivalent of/successor to the KM2P:

http://www.kanzaki-kokyukoki.jp/marineggears/mechanical/TTMC2P-1/TTMC2P-1.pdf


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## JimM (Jul 4, 2007)

The cable on my yanmar 19hp had suddenly broken a couple times in the last year. Anyone have a similar problem -- or a suggestion?


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## arf145 (Jul 25, 2007)

Jim, it would be a good idea to post a new problem like this in a new thread instead of as a response to an old thread like this. I think you'll get a better response. Also would be good to say exactly which cable, your engine model (if you know) and any other relevant details, like where does it break? etc.

Tom


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## sailingdog (Mar 19, 2006)

JimM-

Arf's right... also, might suggest you read the post in my signature, as it will help you get more out of your time on sailnet.


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