My Petter a1 project
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My Petter a1 project
Hi All, I am a newbie and have just joined the forum I am also new to the world of stationary engines and have recently purchased a Petter A1 Petrol/Paraffin single cylinder which I believe could date back to the late 1940s. Its on the verge of running but will not spark properly when the engine speed builds up, I believe this is down to the points/condenser which I will be replacing when funds allow.
Petter77- I really need to post more
- Posts : 8
Join date : 2016-03-29
Re: My Petter a1 project
Hi Steve welcome to the Forum you/l enjoy it and find all the help and advice you need on here from a great group That Petter looks like a nice project Good luck
tony RA- A credit to the forum
- Posts : 278
Join date : 2013-11-16
Age : 76
Location : newtown powys
Re: My Petter a1 project
Hi Steve.
Welcome to the forum. As Tony says, a very friendly and helpful bunch here.
Finished our Petter A1 (petrol only) last year. As regards running - it could also be fuel issue, impulse sticking or even plug. I wouldn't lash out on new parts until you have cleaned everything up, checked points / plug gaps and isolated the problem. I notice you have replaced HT lead - did you use non-restive lead/plug?
I have a manual, which includes 'Trouble shooting' guide Also . PM me if you would like a copy.
Good luck.
Welcome to the forum. As Tony says, a very friendly and helpful bunch here.
Finished our Petter A1 (petrol only) last year. As regards running - it could also be fuel issue, impulse sticking or even plug. I wouldn't lash out on new parts until you have cleaned everything up, checked points / plug gaps and isolated the problem. I notice you have replaced HT lead - did you use non-restive lead/plug?
I have a manual, which includes 'Trouble shooting' guide Also . PM me if you would like a copy.
Good luck.
_________________
Regards Paul
Tha can alus tell a Yorkshireman - but tha can't tell him much.
Woodsman- Admin
- Posts : 2655
Join date : 2014-08-24
Age : 72
Location : God's own county
Re: My Petter a1 project
Thank you for the warm welcome guys, regards to what the issues could be well so far I have stripped cleaned and reassembled the carb, cleaned the fuel line and washed through the tank. I have also taken the cylinder head off and apart from a little bore glazing it looks to be ok with just a little bit of carbon build up on the tops of the valves, on the ignition side I have taken the magneto off and cleaned the points and readjusted the gap however I have noticed when the impulse clicks I get a great spark but when you turn the engine over fast enough the spark goes either very weak or completely disapears, at all any ideas on what this could be?The HT lead is new copper wired as is the spark plug, I will check the Cap later for any resistance but it was bought from ebay as a "non-resistor" one.I believe with this issue sorted out it would most likely run ok
Petter77- I really need to post more
- Posts : 8
Join date : 2016-03-29
Re: My Petter a1 project
Hi Steve,
No doubt others will correct me if I'm wrong, but my understanding is that the impulse coupling is designed to wind up like a spring and then be released at the right moment to produce a faster rotation. Once the engine reaches 165 RPM it cuts out. It also provides a retarded spark for starting and automatically advances as the engine speeds up.
If you are getting a big fat spark on the impulse then I'm guessing the coil is OK.
I await being shot down in flames by more experienced members.
No doubt others will correct me if I'm wrong, but my understanding is that the impulse coupling is designed to wind up like a spring and then be released at the right moment to produce a faster rotation. Once the engine reaches 165 RPM it cuts out. It also provides a retarded spark for starting and automatically advances as the engine speeds up.
If you are getting a big fat spark on the impulse then I'm guessing the coil is OK.
I await being shot down in flames by more experienced members.
_________________
Regards Paul
Tha can alus tell a Yorkshireman - but tha can't tell him much.
Woodsman- Admin
- Posts : 2655
Join date : 2014-08-24
Age : 72
Location : God's own county
Re: My Petter a1 project
Woodsman wrote:Hi Steve,
No doubt others will correct me if I'm wrong, but my understanding is that the impulse coupling is designed to wind up like a spring and then be released at the right moment to produce a faster rotation. Once the engine reaches 165 RPM it cuts out. It also provides a retarded spark for starting and automatically advances as the engine speeds up.
If you are getting a big fat spark on the impulse then I'm guessing the coil is OK.
I await being shot down in flames by more experienced members.
I have watched the Magneto as I turn the engine over and the impulse mechanism from what i can see is indeed spring loaded and holds the shaft of the magneto for about a 1/4 of a turn and then just before TDC it snaps back around at considerable speed by 1/4 of a turn. The strange part is the spark is fine when doing this but once the speed picks up it literally disappears almost indicating that it switches over to a second winding when reaching speed.I did also notice a spark at the points themselves which could also indicate a condenser failure, if that is the case ideally I need to source a replacement from somewhere that would fit and ideally be cheap
Petter77- I really need to post more
- Posts : 8
Join date : 2016-03-29
Re: My Petter a1 project
Well had another play about with it today, I readjusted the points to 0.020 and also adjusted the plug to the same gap. I then made sure the timing was correct by checking the impulse clicked at TDC. Once I had done all this I put petrol into it and it fired up third turn
Petter77- I really need to post more
- Posts : 8
Join date : 2016-03-29
Re: My Petter a1 project
Hi Steve,
Check manual - points should be 15 thou and plug 20 thou. Also check tappets 10 thou both.
Check manual - points should be 15 thou and plug 20 thou. Also check tappets 10 thou both.
_________________
Regards Paul
Tha can alus tell a Yorkshireman - but tha can't tell him much.
Woodsman- Admin
- Posts : 2655
Join date : 2014-08-24
Age : 72
Location : God's own county
Re: My Petter a1 project
Woodsman wrote:Hi Steve,
Check manual - points should be 15 thou and plug 20 thou. Also check tappets 10 thou both.
Thank you yes you are correct I had misread the manual I have got, I have re-adjusted the points to 15 thou and it now runs a lot better and evenly, I have not checked the tappets yet are they easy to do?
Petter77- I really need to post more
- Posts : 8
Join date : 2016-03-29
Re: My Petter a1 project
Tappets are a bit fiddly but not an issue - just follow the manual and you will be fine. Need two good, wear free spanners.
_________________
Regards Paul
Tha can alus tell a Yorkshireman - but tha can't tell him much.
Woodsman- Admin
- Posts : 2655
Join date : 2014-08-24
Age : 72
Location : God's own county
Re: My Petter a1 project
Usually you need to time the actual time that the points open with the impulse inactive to get the ideal ignition timing. The timing of the impulse is not that criticle, (provided it is after TDC to prevent backfiring). Remember the engine spends nearly all it's time running with the impulse inactive.
Sparking at the points and weak ignition once over the impulse speed suggests capacitor fault and/or mildly dirty points. Occasionally spark plug faults can cause misfire at wider throttle settings when the compression is higher.
Sparking at the points and weak ignition once over the impulse speed suggests capacitor fault and/or mildly dirty points. Occasionally spark plug faults can cause misfire at wider throttle settings when the compression is higher.
Darryl Ovens- Expert
- Posts : 64
Join date : 2013-12-04
Location : New Zealand
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