Archimedes Penta

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paddyc

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Hi, Im trying to restore an Archimedes Penta 50a outboard (5HP) It looks in good nick -great compression . I need set of points and condenser - anyone know where I might get same. any info on engine would be appreciated
Regards,
Paddy
 
You will be very lucky to get any spares for that now. I have a 5HP Volvo Penta 51. That's probably very similar.

The best you can do will be to clean the old points up. Any car type condenser (indeed any ignition system condenser) that you can fit in there will do. But like modern outboards modern cars of course have electronic systems so the range of condensers readily available is rather small, non existent maybe. Try a lawn mower repair shop they may have something that'll do.
 
I.ve cleaned the points and tested the condencer and have lift off . Any idea what the points should be set to . They appear to be very tight .015 -(I thought they should be at least 0.020) I'm looking forward to taking it out on the lake on a trial run tomorrow evening weather permitting.--- Thanks for your help
 
On the VP 51 and the smaller VP 39 the points gap is 0.30 - 0.40 mm (0.012" - 0.016")

The plug gap is 0.50mm (0.020") The plug type is Bosch W240 TI

VP recommended a 2% fuel mix if using VP outboard oil but 3% if using other brands (illogical) I always used 2% whatever brand.

Being air cooled I reckon an aircooled engine oil should be better eg motorcycle 2T oil or even 2T lawnmower oil.

I used to have trouble with the plug fouling at idle speeds especially after a good run ie when very hot. An air cooled engine oil might have prevented that. (Keep a spare plug and spanner handy)

EP90 oil for the gear box

A rotten engine that did not stand up well to use in salt water, being air cooled noisy and temperamental because of the plug fouling. Pensioned off in 1985 after 7 years use but it recently did a season for a friend without an engine.
 
I,m using 2T Motorcycle oil & there is a new plug already in it NGT B6HS ---If that doesn't work out I'll try the Bosch W240 TI . Hopefully it might go better in fresh water on the Lake. !
I'll post up the outcome tomorrow evening.
 
I also have a champion L 81 which looks similar to the (original) Bosch one or maybe a little cooler and a NGK B7HS which looks as though it is a hotter grade. I did experiment a bit with plug grades but never came to any conclusions and I forget now how the numbers vary with heat rating although I vaguely remember that the Champion and NGK one are the opposite way round. One gets hotter as the numbers go up and the other gets cooler!
 
A B7HS is a softer(hotter plug) plug than a B8 or B9HS. Be very careful about using softer(hotter) plugs as it's easy to burn holes in pistons due to pre ignition.

I would only use a B7 if the B8 looked oily or I was running at mostly low revs.
 
Thanks for clarifying that. I think I bought the BH7S to try a hotter plug because the original one was always black, oily and tending to foul up. Paddy has a B6HS so presumably that is hotter still so he should not have problems with fouling but if he is running it at high revs he will risk burning the piston but we do not know for sure what is the recommended plug for his engine.

In my case the engine was used as an auxilliary on a small sailing cruiser so was seldom run at high revs.
 
B6HS is the regular plug.

Check Here
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Thanks for that link. The B6HS is the recommended one for my VP51 as well. If that is hotter than the B7HS then I should have tried one long ago. Even that looks as though it is hotter than the original Bosch and I am pretty certain I was sold it as a hotter grade.

Any way it confirms that Paddy has the correct plug
 
Just a little tip. With two strokes the vunerable time for burning holes in pistons is when the throttle is closed rapidly from high revs. What happens is the mixture becomes very weak and for a second or two burns very hot. It's always best to close the throttle gently from high revs.
 
Hi all,
I've had a run out this evening and the old penta started on the second pull. Would go forever on full throttle although I thought it lacked a bit of power compared to a Yamaha 5BS that I also have (another story). From the info received true to form it spluttered and stopped when I trolled at low speed and refused to start again . As I broke the pull cord I gave up for this evening and will not get a chance again until Saturday to try something else. Keep the advice coming as its been great so far
 
[ QUOTE ]
when I trolled at low speed and refused to start again

[/ QUOTE ] You'll have to clean the plug! Thats why I said always have a spare plug and the plug spanner handy. What I found was that if I progressively reduced the speed over a few minutes after a run I could eventually slow it down to idle then it would be ok but not if I just shut the throttle and expected it to idle. I can't begin to explain that!

Re the power compared with the Yammy. The basis of quoting HP was changed back around the late 1970s or early 1980s from quoting the power developed by the engine to the power delivered at the prop so an old 5hp would only rate 4 and a bit on the new system. Also the power you can make use of is affected by the propeller size. For a fast dinghy you would go for a coarse pitch prop but for a slower displacement hull you would go for a finer pitch and slightly larger diameter.

You should be able to change the cord without letting the spring escape but you have to wind it up so to speak so that it then pulls the new cord in as you release it. It needs three hands ideally if I remember correctly.
 
No problem with changing pullcord as all you have to do is open the screw and lift off. fit cord & wind it clockwise - pull string out to grip and slot back spool in making sure to slide into spring . Looking forward to trying engine out tomorrow and this time I'll ease down from full throttle and see if it will idle ok. I've a sprare plug and spanner to hand just in case
 
Hi all, Have solved the plug fouling up. VicS was on the ball - slowly reducing speed allows you to troll. Although the engine cut out a few times it started every time from the pullcord without having to clean the plug. A little fine tuning and the old penta can give a few more years service. Thanks for all the advice. ( next project is the get my Yamaha 5BS back running again)
 
Thanks for reporting back. It should not be necessary to reduce speed gradually of couse but it just seems to solve a problem with this particular engine.

I've looked deeper into the plug recommendations and it seems that the B7HS was the one recommended by the engine manufacturer (Its what the instruction book say) but B6HS is the one recommended by NGK.

A some stage you might want to look at the carb adjustments and maybe clean the jets. Is it a Bing? If it is it is clearly marked on the top where the slow running mixture screw is located. If you are tempted to remove the slow running jet, which is the hex head next to the adjustment screw and concentric with the bowl and the main jet, be warned that it seats on to a teeny-tiny washer that some times comes out on the jet and sometimes stays behind. Make sure you locate it and do not lose it!
 
i have a Archimedes Penta 50a it has no spark and fuel line is gone can i find parts for this ? or i would sell it for a part motor
 
Does anyone know where I can purchase the coil and capacitor condenser for my penta 51
The coil is Bosch 2 204 21 1041 the capacitor 1 237 330 035
 
Frank W said:
Does anyone know where I can purchase the coil and capacitor condenser for my penta 51
The coil is Bosch 2 204 21 1041 the capacitor 1 237 330 035
Click to expand...
Given that you are replying to an eight year old resurrection of a fourteen year old thread ...

Googling the coil finds it unobtainble on Amazon but changing ".co.uk" to ".de" finds it in Germany: Zündspule wie 2 204 211 043 für Hercules Mofa Moped, Zündapp CS25, CS50, Hai, CX, ZX,GTS C Sport 50, ZD: Citomerx: Amazon.de: Auto. They have the capacitor too: Bosch 1 237 330 035 Kondensator, Zündanlage: Amazon.de: Auto
 
paddyc said:
Hi, Im trying to restore an Archimedes Penta 50a outboard (5HP) It looks in good nick -great compression . I need set of points and condenser - anyone know where I might get same. any info on engine would be appreciated
Regards,
Paddy
Click to expand...
I had one, apparently the points they used were "bought in" from a well known maker of distributors. Bit like Lotus Elans having a Back Axle from a Triumph Herald. (Guess how I know)
 
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