Petter A1 rebuild and Parts

Hello all, I was recently given a Petter A1 petrol engine to restore,
I used to have a restored LD1 but had to give it away to make space,
i'll get another one one day...
Anyway I know A1's aren't all that great but it's still interesting
working on it! It's got a good spark now I cleaned up the mag and the
carb is repaired but when I turn it over with my hand over the exhaust
I feel it blow AND suck through it, this indicates the valves are not
sealing properly and this is backed up by a very low compression
figure from a compression tester. I want to grind the valves in and
clean out the carbon buildup that is almost certainly in there,
however, does anyone have a number for a company that can supply me
the gaskets i'll need? I will need a head gasket and presumably one
for under the cylinder where it meets the block, or isn't there one
there? I have made my own carb gaskets using gasket paper but can you
get material to make head gaskets?
Here are some pics and text I have put together and will update as I
do other jobs
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Cheers for any info!
James
Reply to
Endacy
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hiya mate, luckily for you, i also restore PETTER A's, A1 especially, theres several things you need to watch out for.
The magneto connection to the crank case, (the aluminum bracket crystalises and breaks apart as soon as you take it off, these are very hard to replace,
The gasket that goes between the cylinder head, and the barrel, is made out of copper, they can be brought for about £6, I cant remeber off the top of my head where, although i know you can buy them fairly easily,
Best bet for now is check SEM (stationary Engine Magizine). There are several stockist though and i will continue to do my research into which it is.
On the compression side, of things simply either one of the following, take the head off, and de coke the engine by removing the vavles, be careful as the colics ping out and are very difficult to find, clean the valves with emrey cloth, then with sand paper or maybe a chisel if its really lumpy scrap off the crud, then using griding paste, corse to start with, grind the valve back in, i dunno if u know how to do this but ill tell you nehow, its as simple as 4 steps:
1. covered the seat in the griding paste 2.place valve back in it checkin its the correct one. EX on the left side, ive always found. 3.twist it with a screwdriver and let the valve make the paste go green, simple keep turnging alternate directions and eveyr so often pick up the valve spin it round n drop it back in, and proceeed again untill u get a dull grey line round the top of the valve and the edge of the value hole. roughly about 2 mm thick, 4. replace the colic with a valve compression tool.
or the easier way although im not sure if it will work, is to, (ive used this method and it dose work) if u are sure u have fuel into your engine via the carb take a syringe and fill it up with 5 ml petrol spray it down the bore, replace the spark which should be a C14 lodge, i do have conversions if you need it, then crank it over, it will fire very rich but it the engine is correct it will get it going the the pistion will bind itself back in. please remember this is what i use, maybe not the best of solutions but it makes the engine run,
Martyn, hope it helps, ill try and find them numbers for you, and i may as well post the conversions for the spark plugs anyhow for a PETTER A/A1
PS: hope it goes well, there great engines, in my eyes, please just check the cowlin is in wicked condition if not i recommend you dont run it any longer than a few seconds, me
Reply to
Martyn Butler
hiya mate, luckily for you, i also restore PETTER A's, A1 especially, theres several things you need to watch out for.
The magneto connection to the crank case, (the aluminum bracket crystalises and breaks apart as soon as you take it off, these are very hard to replace,
The gasket that goes between the cylinder head, and the barrel, is made out of copper, they can be brought for about £6, I cant remeber off the top of my head where, although i know you can buy them fairly easily,
Best bet for now is check SEM (stationary Engine Magizine). There are several stockist though and i will continue to do my research into which it is.
On the compression side, of things simply either one of the following, take the head off, and de coke the engine by removing the vavles, be careful as the colics ping out and are very difficult to find, clean the valves with emrey cloth, then with sand paper or maybe a chisel if its really lumpy scrap off the crud, then using griding paste, corse to start with, grind the valve back in, i dunno if u know how to do this but ill tell you nehow, its as simple as 4 steps:
1. covered the seat in the griding paste 2.place valve back in it checkin its the correct one. EX on the left side, ive always found. 3.twist it with a screwdriver and let the valve make the paste go green, simple keep turnging alternate directions and eveyr so often pick up the valve spin it round n drop it back in, and proceeed again untill u get a dull grey line round the top of the valve and the edge of the value hole. roughly about 2 mm thick, 4. replace the colic with a valve compression tool.
or the easier way although im not sure if it will work, is to, (ive used this method and it dose work) if u are sure u have fuel into your engine via the carb take a syringe and fill it up with 5 ml petrol spray it down the bore, replace the spark which should be a C14 lodge, i do have conversions if you need it, then crank it over, it will fire very rich but it the engine is correct it will get it going the the pistion will bind itself back in. please remember this is what i use, maybe not the best of solutions but it makes the engine run,
Martyn, hope it helps, ill try and find them numbers for you, and i may as well post the conversions for the spark plugs anyhow for a PETTER A/A1
PS: hope it goes well, there great engines, in my eyes, please just check the cowlin is in wicked condition if not i recommend you dont run it any longer than a few seconds, me
Reply to
Martyn Butler
Can't help with your gaskets I'm afraid. Interesting pictures though. You mentioned the lack of exhaust. My A1 is an ex military engine and it has never had a normal exhaust. The exhaust outlet is simply a piece of pipe about 2" long with a cross hole drilled in it. The actual exhaust is a length of flexible pipe with a silencer at the end. This was slipped over the stub pipe and retained by a split pin through the cross hole. I assume that the engine was meant to be run in a tent with the exhaust piped to the outside. It seems to work well enough.
John
Reply to
John Manders
A similar exhaust set up seems to have been used for most small military gennies. My JAP 5 uses such and I managed to buy a batch at our local ex-gov dealer a few years back. ttfn Roland
Reply to
Roland and Celia Craven
Copper-asbestos head gaskets are actually designed to be re-useable (de-coking used to be a pretty regular job) so remove the head carefully and providing it has not been abused in the past, you may well get away with it.
It is also possible that the exhaust valve is just sticking or sitting on a bit of loose carbon, so before going any further it's worth taking the tappet cover off, freeing valve if neccesary then levering it a few times letting it snap back onto its seat.
Reply to
Nick H
Cheers for the help guys! In the post today I got a back issue of SEM showing a rebuilt one of these, looks good! I also recieved a parcel with another manifold and carb that I bought as a spare should I need it.
Today I took the head off and found the head gasket is in fairly good nick, so I should be OK there. There was lots of carbon buildup but before I bother grinding the valves in, how much play should a piston have in the bore of one of these engines? I can wobble the piston in the bore with somewhere between 3-8 thou of play (maybe, not to sure!), quite a bit. Is this normal to allow for expansion? It seems like way too much. I managed to get the valves out with some creativity, the exhaust valve is slightly worn but it isn't too bad. The bore has no discernable wear step at the top however it does have a score down it that i can feel with my fingernail, how serious is this considering this isn't a car engine? I don't intend on taking the engine apart much more than this if I can get it running OK as it is but am I into piston out time now?
Oh i have a added a few pics to my page.
Cheers
James
Reply to
Endacy
Hey , My Petter A is in a similar state to yours at the moment , one thing I noticed that is different is that the starting handle appears to be on the other side of the engine to the flywheel , is this the normal place it should be ? The starting handle on mine slides onto the flywheel axel with a round bolted 'blanking plate' over the area where the axel prutrudes on your engine . Im sure both designs work well , just wondering if and why my engine has been modified . Try to get some pictures in the near future Cheers , Max
Reply to
Max Wilkinson
It is the difference between a Mk I and Mk II A1 (according to my parts catalogue).
Reply to
use_reply_to_address_but_not
Which is which ?
Reply to
Max Wilkinson
MkII (and Mk III and Mk IV) uses starting handle on "flywheel axle".
Reply to
use_reply_to_address_but_not
I'd not have thought that amount of piston slap or scoring was relevant in such a low compression engine, especially one that is no longer likely to see a great deal of heavy work.
That said, if t'wer I, I'd have the barrel off now you've got this far and look at the rings which may be broken. If so, they will chaw up the bore summut 'orrid, heavily loaded or no! Catching it early will just mean a set of rings, but when they have danced up and down in the ring grooves for a while, they'll gnaw away the ring lands too and then its New Piston & Rebore time.
Regards,
Kim Siddorn,
Reply to
J K Siddorn
Hmm, good point there, I suppose i'd better whip the barrel off tomorrow, I hope the gasket is similar to the head and comes off in one piece. I spent ages today grinding in the valves and refitting them with the barrel in place, that's a nightmare job...oh well fun job tomorrow then! Cheers for the help.
Reply to
Endacy
If the base gasket tears, a new one can easily be cut out of a cereal packet.
Get a tube of silicone sealer, put a blob on finger and thumb and work it into the cardboard all the way round. Coat it both sides with the thinnest possible layer. Put it aside to dry for 24 hours and you will have created a rubber faced gasket that will NOT leak.
If you fit it straight away with the Silicone wet, it will probably seep oil along the joint line. Wait the extra day and get a nice, dry engine!
Regards,
Kim Siddorn,
Reply to
J K Siddorn
Thanks for the advice about gaskets, I actually made one using proper gasket paper in the end, I can get it from my local motor factors. The piston and rings were fine until I tried to take the bottom ring off to clean it (the one with the holes - oil scraper?) and it promptly broke in half. So anyone know where I can get spares? I'll give a few numbers a go that I can find in my back issue of SEM and will probably just subscribe anyway but if anyone has a number to hand that'd be great. No new pictures yet, always too oily to use the digital camera!
Reply to
Endacy
Trevor Maddock
01244 851227
Regards,
Kim
Reply to
J K Siddorn
Been a while, Trevor Maddock provided a new oil scraper ring and i've updated the page, it has run! Needed some ingenuity to fix a sheared stud...check it out.
Reply to
Endacy
Well done. You are now on the slippery path that leads through insanity to the award of an anorak :-) BSF/BSW taps and dies can be picked up at Jumbles or bought second hand very reasonably from the likes of Pennyfarthing tools or the Toolbox. regards
Reply to
Roland and Celia Craven
I have a Petter A1. I visited Dorset Steam Fair and found one running. This filled me with 'go' and after some TLC mine runs too - after maybe 35 years waiting. I need paint tint, transfers, manual, club.
Old 20 Parts sent a flyer about 4 years ago NVTEC. Web site?
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Reply to
No Name
H I I'm a newbee but surfed and found this thread I've just got an A1 and can't get it running Fires every 1/2 pull but won't keep running. Carb cleaned, new fuel and a good spark. Good compression. No kick back or popping through the carb. One or 2 pops then stops......Suggestions
Reply to
Whittler Kev

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