george i have received this email from thornycroft
----------------- Forwarded Message: Subj:RE: engine Date:11/06/2008 09:32:08 Pacific Daylight TimeFrom:<a href="mailtoales@thornycroftengines.co.uk" title="mailtoales@thornycroftengines.co.uk">sales@thornycroftengines.co.uk</a>To:<a href="mailto:BarSho5@aol.com" title="mailto:BarSho5@aol.com">BarSho5@aol.com</a>Sent from the Internet <a href="aolmsg://05405de8/inethdr/2" title="Internet Header Details">(Details)</a>
Thank you for your enquiry. In neutral the engine RPM should be approx 3200 RPM. In gear under full load, engine RPM should be approx 2800 RPM. Lack of power (RPM) at the propeller can be due to the following: Flexible drive plate between engine flywheel and gearbox input shaft – check/renewEngine has poor compression and lacks power and needs overhauling – check piston bore wear.Fuel starvation – blocked fuel filters, injectors, etc, air in the fuel system, fuel lift pump failed/failing. - This is the most likely scenario based on your email.Gearbox slipping – check/renew clutch platesPropeller and/or shaft damage – check/replace Kind RegardsShaun McConnellTHORNYCROFT ENGINES<a href="mailtohaun@thornycroftengines.co.uk" title="mailtohaun@thornycroftengines.co.uk">mailtohaun@thornycroftengines.co.uk</a><a href="http://www.thornycroftengines.co.uk/" title="http://www.thornycroftengines.co.uk/">http://www.thornycroftengines.co.uk/</a>Tel: +44 (0) 1772 611144Fax: +44 (0) 1772 616364----------------------------------------------------------------This E-mail is intended only for the addressee named above. This e-mail may contain confidential or privileged information and will be protected by copyright. If you receive it in error, or are not the named addressee, or the person responsible for delivering the message to the named addressee, please notify us, and delete it immediately. The contents must not be disclosed to another person nor copies taken. Any views or opinions are solely those of the author and do not necessarily represent those of Thornycroft Engines. While this e-mail has been scanned for viruses prior to transmission, the e-mail cannot be guaranteed to be secure, error free or free from viruses. Thornycroft Engines does not accept any liability whatsoever for any loss or damage which may be caused as a result of the transmission of this message by e-mail. Thornycroft Engines is a trading division of AMC Diesel Engineering Ltd. Registered in England 2151529
Please remember that a single lever morse control operates both the gearbox and the throttle.
Does engine lock of at 1500 rpm both forward and astern?
Quirky things can happen-I had scenerio where the cable mounting for the throttle on the fuel injector pump had worked its way loose such that instead of the wire pulling the throttle lever on the fuel pump the mount rotated backwards along with the bowden cable cover-result throttle was only being pulled half on despite morse lever full ahead/astern.
You need to check forward and reverse rpms by operating lever at pump
Important I think to go back to when and how problem occured-did it develop slowly?Did it appear this spring but no problem last year-perhaps fuel bug-if you have a watertrap on bottom of filter unscrew tap and collect what comes out of drain/shine a torch on filter if it has a glass bowl-quite obvious if somethings wrong.
Before thinking diesel bug is the filter new?-is the engine smoking in any way.Certainly a blocked filter will cause these symptoms and a blocked filter can arise quite quickly-once had one block on my Nissan Terrano(a garage service-not!)-one minute cruising at 70mph then the first hill I got to began loosing power and was quite happy to cruise a further 100 mls of M6 motorway driving being only unhappy when asked to pull up over Shap-ie there was not enough fuel getting thru to provide enough when extra was needed for hills/as with low rpms on your engine..
Certainly worth buying a book on diesels which usually includes a systematic fault diagnosis table /diagram/google it
I think we can all be categoric that neither of these will solve your problem, they are fuel additives designed to improve the combustion of diesel and also claim to clean hadened deposits off the injector nozzles.
What you have seems to be a serious blockage within the fuel delivery system. Neither of these products will have any effect on this problem and are franky fairly pointless in most marine (and probably any other ) engines.
If it is the diesel bug then only a SPECIALIST BUG KILLER like Diesel 16 (it is used by Shell & Nato for this purpose) will work for you.
Following up from Phil's point, when was the engine last serviced?
When were the fuel filters last changed, when was the fuel system last bled?
It would be worth thoroughly bleeding the fuel system and going over every connection/joint with a spanner , even the slightest amount of air in the system could be causing this problem.
However my bet is that its the bug and if you have it, then even if you strip and clean the system, it will work ok today, but give it a few hours and it will be blocked again, it is only by treating the fuel with Marine 16 that you will kill the bug (it is a bacteria) and ensure that it never returns.
I read an article in one of the yachting magazines last year in which they recommended (after trials) GRATAMAR 71 to get rid of the dreaded 'Fuel Bug.' I was at the boat yesterday and have used it in my tank. I will of course inform you of the results.
Great am not familiar with that one but if its been indepenently validated it should do the trick!
If it is the bug a decent dosage and a few hour should clear it out, did you run the engne for a while after you dosed the fuel, to get the stuf right through the system.
Lets hope this sorts it out for you, and if it is the bug, you wont have to spend a fortune on engineers and new bits!
Having spent MANY, MANY, MANY, hours in the marina, the fault has now been found and rectified. The engineer found (after two visits) that the slide in the Morse had broken in half so had it welded and refitted. This, however, did not rectify the fault so he decided a new cutless bearing was required and that the prop shaft was possibly bent.
Luckily for me, a couple of days later, a motor mechanic was tuning the engine of a motor boat on a nearby pontoon, so I asked him if he'd kindly take a look at mine. This he did, and, having given the engine a thorough check, he conclude that the engine was in MINT condition and was in no way at fault. He then asked what type of prop was fitted; on advising him it was a THREE BLADED FOLDING type he said the prop shaft was definately not bent and he very much doubted whether the cutless bearing requred renewing - he went on to say, he would put his shirt on it, that the fault was, at least one of the blades on the folding prop being stuck, possibly in reverse!
He was, of course SPOT-ON!
I instructed him to remove the 3 Bladed folding prop and throw it as far as he could muster the strength, then fit a new 2 blader. He didn't of course, as it cost the best part of £1000!
He re-tuned my engine and it is now so quiet I have to listen carefully to see if it is running. I later learnt that he tunes racing cars, and, believe it or not, he only charged me £100!
Guess who will be booked to do any engine type work on my yacht in the future!
May I take this opportunity to thank David Evans 5, Phil Dobson, Scotty and Gwil Harris-Evans, for their kind suggestions to solutions on my problem.
So to be clear it was a feathering prop and one of the blades was stuck in reverse
Or was it a free feathering type like a Brunton?
Or was it a folding prop and one of the blades wasn't opening?
Unless it was a Brunton type, you may get this again as it sounds as if the gear mechanism n the prop itself may have jumped a tooth or two, which is indicative of wear and needs exxxamining to be sure it cannot happen again.
If it is wear on the gears/cogs it is a simple job for a decent engineer to put metal back onto the component and re-cut the gears - a lot cheaper than a new prop!
I have seen this happen once before and it was the gear mechanism that was worn, must admit I clean forgot abouut it!
Great to hear your problem is solved at last. Your experience certainly underlines the need to look at the simple answers first, before rushing into expensive repairs. We recently plugged our boat into shore power, and when the battery charger didn't spring into life, were immediately, pessimistically convinced it was the charger (expensive) that had failed. However, after a little thought we examined the power cable and all that had happened was that water had got into one of the plugs (cheap) and dissolved a connection.
We have a three bladed feathering prop (Maxprop) that we are delighted with. However, we did once take it off (to replace the sail drive gasket) and put it back without setting it up properly, and managed to reverse it, so that the boat went backwards with the gear lever in ahead and vice versa. Fortunately this meant we realised where the problem was! If it had been the right way round, and just pitched wrong, we would doubtless have been convinced it was the gear box or engine controls that were at fault. The mistake was easily rectified, DIY with the help of the instruction manual - although of course we had to pay for the boat to be lifted out again, no sooner than she had been launched!
My old prop was a feathering prop and one of the blades was stuck in revers. The gear mechanism in the prop itself had jumped a tooth or two.
I have ditched my feathering prop and reverted to my old two bladed prop (I have been sailing for over 50 years and still do long distance racing) and can see no speed advantage of the feathering prop. (I also have a rope cutter fitted)!
My delay in replying is because I have just returned to my marina at Hartlepool, from cruising around holland, Belgium etc,.
Thanks to all who took the time and trouble to comment.
ales@thornycroftengines.co.uk" title="mailto
