Possible gearbox trouble - oh woe

Robert Wilson said:
I'm now looking at racking-up some large expenditure for parts and labour because I'm at the limit of my own DIY abilities.​
If the next tests (exhaust, injectors/pump) prove a failure then I'm thinking of a new engine plus various ancillaries.
Big hit on my finances, but I'm getting tired of scrambling around in tight, dark, painful spaces and coming home stinky and filthy- and I'm not as lithe as I used to be.:eek:

I know it won't add the overall purchase and installation costs to the sale value of the boat, but I want to enjoy fear- and hassle-free sailing.
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While I can't offer any certain solutions, and I know only too well what a grind it can be dealing with such trials, I suspect you are being overly gloomy about the outlook.

As I understand it, your engine and drive were fine before you took it out of the water for a while. It still starts OK; it still ticks over, runs and revs fine in neutral; and it still goes in and out of fwd and reverse OK. It has, however, 'suddenly' lost the ability to give full power. That's the only thing that's wrong. I find it hard to believe that combination of results is caused by excessive wear/agedness, or some major failure. It is likely to be something simple, or some combination of simple problems.

I think you and the forum have all but eliminated the gearbox and prop as the problem. I doubt the injectors have anything to do with it, or at least that would be revealed by 'cracking' them at idle, as you say it is running OK apart from the power .

I can't see that a new engine is called for. The biggest risk, I think, is that a 'professional' you might hand it to will fail to apply logic, and could run up a large bill wasting time trying random things and replacing things that can't (or are very unlikely to) be causing the problem. Even then it would have to get completely out of hand to be worth replacing the engine to avoid (and if you have an engineer like that, the installation ain't going to going to go smoothly or cheaply).

I'm no engineer, but just by a process of deduction my money is still on either not enough fuel flow (e.g. blockage; pump failure), not enough airflow (but you didn't report smoke), or not enough exhaust flow (e.g. elbow blockage; exhaust hose internal collapse). The exhaust is relatively(!) easy and inexpensive to check. As Charles Reed said, 'the only way to check out possible causes for engine power reduction is to carry out a series of tests, in inverse order to their probability'. (He could have added cost!)

Don't despair (or at least, no too much!). Hope you can get some sailing in despite the problem.
 
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Great post, thank you.
My initial thoughts (fears) was that the gearbox and/or cable was malfunctioning, then all sorts of other thoughts/ideas/warnings came over the forum.
This has led me on a frustrating, tedious and disappointing journey - and then you come along and I'm back at the beginning!!!

I'll do as you suggest, and how ironic it might be if the gear-change is the culprit after all.

I presume you have put the box into neutral and rotated to shaft by hand to see if there is any resistance?
Yes I have, and there's virtually no resistance at all (a little from the stern gland/cutlass bearing)
Have you tried disconnecting the gear change cable at the gearbox and changed gear manually at the box to see what happens?
No not yet due to kind and well-intentioned diversionary suggestions
Do you have the loss of power in both forward and reverse?
Yes, I get about half revs

email address - PM about to be sent. And I'll contact Mike Pilkington

Thanks for your input

P.S. Edit:-
This was posted before Littlesister's latest post. To be fair to you and Littlesister I will check to cable and selector arm - just to eliminate the possibility it is after all the culprit.
 
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Thanks LitleSister. and thanks for the encouragement.
I'm with you on not letting-loose an engineer with a blank task schedule and open-ended charge sheet!
I'm also with you on not wanting to re-engine, when the fault may be some relatively minor failure/malfunction.

I have a wee niggle forming that I'll check today, being that when I fitted the Tiny-Tach rev-counter it failed to work on one injector pipe but worked instantly on the other. It might be that the first injector pipe has a fuel-starvation issue.

The forecast and tides look to be perfect this afternoon to bring the boat back from Loch Ewe to Mill Bay (in front of home). With reasonable peace of mind about a "half-power" propulsion unit I'm going to try to enjoy the rest of this season and then attack the whole issue again in the autumn - while keeping a careful eye on performance and "wee noises"!

I'd really rather NOT spend £7,500 on a new engine, especially as it will probably be to someone else's benefit in about ten years time! :(

P.S. Edit:-
I am still going to work away at the issue(s) particularly a potentially blocked exhaust and fuel starvation - but I can do it more easily in front of the house, as opposed to a 3/4mile dinghy trip across the open sea loch!!
 
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That's the first mention that I've noticed of your observation with the Tiny-tach. It lends support to a suspicion that your problem lies with the fuel system, either an injector or one of the HP pump cylinders not doing the business. Certainly possibilities after a lengthy period of dis-use.
 
RichardS said:
I think mine is a Vetus watertrap but I've never noticed any drain plugs. I think mine is plastic or GRP rather than metal but I've never looked at it that closely. I don't know if that makes any difference but I'll have a look next time.
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Mine (LP45) has a drain, but it's at the rear end, under the outlet, and completely, utterly inaccessible without removing the whole thing.
 
JumbleDuck said:
Mine (LP45) has a drain, but it's at the rear end, under the outlet, and completely, utterly inaccessible without removing the whole thing.
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If you look in the Vetus catalogue (open in front of me) all the waterlocks have a drain - and some with two chambers have 2 drains. Inevitably they are at the bottom - otherwise they would not drain.
 
Robert Wilson said:
Great post, thank you.
My initial thoughts (fears) was that the gearbox and/or cable was malfunctioning, then all sorts of other thoughts/ideas/warnings came over the forum.
This has led me on a frustrating, tedious and disappointing journey - and then you come along and I'm back at the beginning!!!

I'll do as you suggest, and how ironic it might be if the gear-change is the culprit after all.

I presume you have put the box into neutral and rotated to shaft by hand to see if there is any resistance?
Yes I have, and there's virtually no resistance at all (a little from the stern gland/cutlass bearing)
Have you tried disconnecting the gear change cable at the gearbox and changed gear manually at the box to see what happens?
No not yet due to kind and well-intentioned diversionary suggestions
Do you have the loss of power in both forward and reverse?
Yes, I get about half revs

email address - PM about to be sent. And I'll contact Mike Pilkington

Thanks for your input

P.S. Edit:-
This was posted before Littlesister's latest post. To be fair to you and Littlesister I will check to cable and selector arm - just to eliminate the possibility it is after all the culprit.
Click to expand...

I did suggest this in post #11.
 
vyv_cox said:
I did suggest this in post #11.
Click to expand...

I know you did Vyv, but I felt I ought to respond in the positive!

As to the Tiny-Tach issue, I haven't had the opportunity to test the fuel flow though to the injectors but I shall by the end of the week.
Oh, wouldn't it be great to find the source of the problem ! - and one fairly easily fixed - bit expensive if it means a new injector pump :( but much less than a new gearbox and all the extra work :encouragement:
​
 
Robert Wilson said:
I'd really rather NOT spend £7,500 on a new engine, especially as it will probably be to someone else's benefit in about ten years time!
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This is an interesting inversion of the argument I used to justify a new engine! My take was if I had (hopefully) ten years before I became incapable, then I'd rather have the benefit of a new engine now than have to re-engine in 5/6/7 years time and, as you say, pay for a new engine for someone else to use (not to mention overhaul costs in the interim).
 
eddystone said:
This is an interesting inversion of the argument I used to justify a new engine! My take was if I had (hopefully) ten years before I became incapable, then I'd rather have the benefit of a new engine now than have to re-engine in 5/6/7 years time and, as you say, pay for a new engine for someone else to use (not to mention overhaul costs in the interim).
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:encouragement: - sound judgement.
But I feel I should rectify the fault (if possible) as I have already spent a fair bit on the engine in one way or another.

Hey ho.
 
Bit late to this... read the first few posts then drifted off...

The semi blocked exhaust didn't sound right as the engine would try to over come this with more fuel= black smoke.
The only cause that shouted was lack of fuel. So if one injector is not doing it, you have it. The Tiny tack clue might be it.
Simple test would be to remove the injector and reconnect it to the high pressure pipe and spin the engine(keeping hands well away..) If it has a nice fine spray, good. But I expect it will not. And that is your problem. Either the injector or the pump. (I am assuming it has two jerk pumps in the block.) injector would be my first pick.
DW
 
DownWest said:
Bit late to this... read the first few posts then drifted off...

The semi blocked exhaust didn't sound right as the engine would try to over come this with more fuel= black smoke.
The only cause that shouted was lack of fuel. So if one injector is not doing it, you have it. The Tiny tack clue might be it.
Simple test would be to remove the injector and reconnect it to the high pressure pipe and spin the engine(keeping hands well away..) If it has a nice fine spray, good. But I expect it will not. And that is your problem. Either the injector or the pump. (I am assuming it has two jerk pumps in the block.) injector would be my first pick.
DW
Click to expand...

I hope to do what you suggest tomorrow, weather permitting for access to the boat.
Many thanks.
Watch this space!!

P.S.
What do you mean by the "high pressure pipe", please?
 
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Habebty said:
Fuel filters?
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I spent a messy and uncomfortable two hours on Monday removing and refixing the filters. Plenty of fuel squirting out using the lift pump and fuel seems to be dribbling from the injectors - BUT I then thought about the Tiny Tach and the problem this incurred.
Perhaps the fuel flow was not as good as it should be.

Further investigation as per my post #137 will be reported.
Thanks.
 
The high pressure pipe is the one that goes from the pump to the injector, usually entering from the side, the return is the one on the top.
A quick test would be to loosen the HP pipe connection and see if it leaks fuel in spurts. If so, then remove the injector and refit the tube with the nozzle facing away and retest. I repeat, do not have any skin anywhere near it as the very high pressure can blow fuel through into the bloodstream and cause severe probs.
I will have a look for pics of the engine.

Looking at Google pix, I might be wrong on the placing of the pipe, it could be the one on the top of the injector. Just follow them from the pump.
 
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