Ariel Owners Motorcycle Club

Many thanks for all your valuable tips. Thank you Karol for the photo for comparison.
As soon as I managed to get the Cylinder block off from the crankcase, I‘m coming back with more details.
I still struggeling with that step.
Martin

To remove the cylinder, put the cylinder head back on and put a few turns on the 8 long special head studs/bolts which hold it down. Put the centre nut onto the bolt between the two cylinders. Then slacken the 8 studs/bolts and this will jack the cylinder up off the crankcase.

paul.jameson wrote: Mon Dec 30, 2024 1:22 pm To remove the cylinder, put the cylinder head back on and put a few turns on the 8 long special head studs/bolts which hold it down. Put the centre nut onto the bolt between the two cylinders. Then slacken the 8 studs/bolts and this will jack the cylinder up off the crankcase.

Just to get it right. Does this mean that the 8 nuts on the cylinder base are only there to guide the bolts and have no function in securing the cylinder? I am asking because the loosened bolts move freely in these cylinder base nuts.
I moved the bolts with the double nuts attached above.

Meanwhile, I tried your procedure Paul and it indeed pretty easy to lift the whole head/block assemble. Thank you very much for this great hint. I ask myself, why those workshop procedures are not mentioned in the manuals.

dave.owen wrote: Sat Dec 28, 2024 5:38 pm Take piston off and check the number inside

Inside I found at one side „Heplex 10930“ and C52
and on the other side „3447 AM 413“ and also a patent number
So it seems to be a Hepolite Piston as Dragonfly sells them

That's a "W" slot split skirt type. The crown runs much hotter with them although the twin oil pump is high volume and would help. Re ring and use as is? Nev.

nevhunter wrote: Tue Dec 31, 2024 12:45 am That's a "W" slot split skirt type. The crown runs much hotter with them although the twin oil pump is high volume and would help. Re ring and use as is? Nev.

This would of course be the cheapest option. There are no traces of jamming or similar on the piston. Only discolouration indicates that it has been blown into the crankcase via the piston rings. Martin

There's life in them still. I always use the solid skirt, unless the Motor is going to get an easy time. That type requires more clearance to ensure it won't nip up. Nev

Hi Martin,

I suspect your carbonisation problem will be partially caused by the rocket feed, which is on the pressure side of the oil pump (unless it’s been modified already). You can find this out for sure by tracing the oil pipe from the rockers and seeing if it joins the crankcase on a small banjo union to the left of the timing cover. If it does, your rocket feed is pressure fed.

If this is the case, when you rebuild, cap that feed and put a junction in the return line, so you don’t get over oiling.

I can provide more details on this if required.


Rob

robjameson wrote: Thu Jan 09, 2025 4:48 pm I suspect your carbonisation problem will be partially caused by the rocket feed, which is on the pressure side of the oil pump (unless it’s been modified already). You can find this out for sure by tracing the oil pipe from the rockers and seeing if it joins the crankcase on a small banjo union to the left of the timing cover. If it does, your rocket feed is pressure fed.
If this is the case, when you rebuild, cap that feed and put a junction in the return line, so you don’t get over oiling.
I can provide more details on this if require
Rob

Hi Rob,

Many thanks for the interesting tip. I have posted a photo here of the backside of my crankcase.
The oil line has already been dismantled, but if I understand you correctly, it's about the connection at the bottom left on the foto.
The photo was taken directly after the engine was lifted out of the frame. So it´s pretty dirty.
If you could explain to me in more detail what I should do, I would be very grateful. Perhaps you also have some pictures of the solution? I assume you also have a KH.
Martin