Watermota Sea Panther

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gusboy

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Hi. I own a Birchwood 25 cruiser fitted with a Watermota Sea Panther diesel engine. This engine runs okay but it is nearly impossible to start. I've had the compression tested which was 295psi, for three cylinders with one at 245psi. I've had the injectors and injector pump tested and all were found to be operating as they should. I have two questions, any advice on starting the engine and secondly, what alternative engine would be the best replacement with the minimum of work.
 
NickRobinson said:
Does it have the 24v set up to the 12v starter? I believe Ford struggled to start them when built...
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Hi Nick, No it has just the normal 12v starter. How does a 24v set up work? Do you have two 12v batteries to provide power to a 12v starter? Or is it a 24v starter?
I've tried pretty well everything else, but it's a real b*****d to start.
Gus.
 
I've never owned one, I have a petrol Kent in my Ford Prefect.
I understand the electrics as original allowed the unit to charge two 12v batts in parallel then the solenoids zapped the standard starter with 24v
 
Diaphragm on the lift pump shot, have you tried 'Pumping' the throttle a few times prior to starting?

Failing that, call Andrew at Sheridan Marine, they know those engines well.
 
NickRobinson said:
I've never owned one, I have a petrol Kent in my Ford Prefect.
I understand the electrics as original allowed the unit to charge two 12v batts in parallel then the solenoids zapped the standard starter with 24v
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I am familiar with the Ford Kent engine, it was ( and still is) used extensively in motor sport, in fact Ford started to manufacture it again long after the Cortinas and Capris ceased to exist as the racing world still used the block. Thank you for drawing my attention to the earlier treads on the Sea Panther, it makes interesting reading. Am I right in assuming the idea is to zap 24v through a 12v starter, I have already gleaned Watermota recommend only pressing the start button for a maximum of 15 seconds, sounds like primitive engineering to me…
 
Our Sea Panther was a pain to start, but eventually it seized up and I got a good price for it on eBay from someone who intended to rebuild it. The replacement, in 2005, was a Beta 28HP, which has been a pleasure to use.
 
harvey38 said:
Diaphragm on the lift pump shot, have you tried 'Pumping' the throttle a few times prior to starting?

Failing that, call Andrew at Sheridan Marine, they know those engines well.
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I have checked the lift pump, pumps diesel just fine, I’ll talk to Andrew at Sheridan Marine, to see what he can advise.
 
Pretty much any starter motor is only rated for a very low duty cycle, generally 10-15 seconds in any minute and at least 5 minutes after 2-3 tries to cool down; ignore that and the thing will burn out sooner rather than later.
 
gusboy said:
sounds like primitive engineering to me…
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Indeed. It was an attempt to get into the high speed 30hp+ diesel market that did not really work out - fundamentally the wrong starting point and lack of funds to really make it work. At the time there was a big gap in the market for boats in the 30-35' size range where the only choice was the old style heavy Volvos or the Perkins and BMC diesels all of which were older designs and relatively crude. Unfortunately it was oversold and good boats like Sadler and Nicholson had them fitted. Yanmar and Volvo came out with 30hp 3 cylinder high speed (3600rpm) lightweight diesels which immediately made the Watermota obsolete.
 
gusboy said:
I am familiar with the Ford Kent engine, it was ( and still is) used extensively in motor sport, in fact Ford started to manufacture it again long after the Cortinas and Capris ceased to exist as the racing world still used the block. Thank you for drawing my attention to the earlier treads on the Sea Panther, it makes interesting reading. Am I right in assuming the idea is to zap 24v through a 12v starter, I have already gleaned Watermota recommend only pressing the start button for a maximum of 15 seconds, sounds like primitive engineering to me…
Click to expand...
A trick from my motor trade days to try. A second 12v battery, connect jump leads. On the solenoid- connect across the big terminals. Don't use starter button it would give you a dead short, sparks certainly but an easy 24v way to see if the beast starts. 1660294392730.png
 
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Hi Nick,

Thank you for your suggestion and drawing. I will give what you say a try. I must say I am still a little unsure about putting 24v through the starter, but if it is the answer I can live with needing to (hopefully only occasionally) fit a new 12v starter. I still can't believe the engine manufacturers thought this was the answer poor starting, but it does say in the manual you should not use the starter for more than 15 seconds at a time and wait a minute or two to allow the starter to cool down, stupid or what!!!
 
gusboy said:
Hi Nick,

Thank you for your suggestion and drawing. I will give what you say a try. I must say I am still a little unsure about putting 24v through the starter, but if it is the answer I can live with needing to (hopefully only occasionally) fit a new 12v starter. I still can't believe the engine manufacturers thought this was the answer poor starting, but it does say in the manual you should not use the starter for more than 15 seconds at a time and wait a minute or two to allow the starter to cool down, stupid or what!!!
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The basic problem of converting a petrol engine to diesel with the need for double the compression ratio without there being a starter motor with sufficient oomph to turn it over fast enough. As I suggested, this was a low budget project with very small numbers of engines built and the 24V for starting was the "fix". Starters were a problem on all the 85 bore engines - short stroke and high compression ratios compared with other engines of the time and dear old Lucas could not keep up with developments.
 
VicS said:
IIRC later engines had 12 volt starting but also had a "thermostart" device for heating the manifold. I assume that was a better/ more effective solution
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My engine is the later version, it has a thermostart in the inlet manifold, I’ve replaced that with a new one, it gets hot and the diesel smokes, but it STILL does not start. I’ve found one way that worked, remove the air filter and jamb a hot air paint stripper into the manifold, it started immediately, but I really want to have remove the cockpit deck each time I need to start the engine. I think I could rig up a paint stripper bolted to an adjacent bulkhead, to do this I would also need 2000kw inverter. If the 24v starter idea works, I think this will be my next move. I would be very happy to GIVE engine to anyone who wants it, all they would need to do is remove it…
 
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