FH wet sumping volume?

[Martin K]

Hi

Haven’t run the ‘new’ (ie all bearings, honing, rebuild) for a few weeks - and even then only for a short time.

I’ve been reading about wet sumping so undid the sump plug and found this much oil fell out.

Good news is the oil is super clear, no swarf, grind or other nasties in the oil and the magnetic sump plug had the merest microscopic silver paste on it. So far so good. Just surprised at that much oil coming out.
Suspect the oil pump (which I didn’t restore or replace) has become ‘a woman of easy virtue’ over the years and has worn a tad slack.

Question: is this amount of wet sumping normal? And if so, when leaving it a while before runs, is it ok to simply drain the excess, pour it back into the tank and off we go, or fit a valve and a ‘remove before flight’ warning tag….

Thanks

Martin

[Roger Gwynn]

That is quite a lot of oil for a few weeks, it has definitely wet sumped. A gear pump in good condition will leak less but will still leak, it's the nature of the beast. You can fit a valve, some people like them some don't, plenty of discussion out there. You can run the bike once a week to pump the oil back but you should really run it until it is warm. Or you can drain the oil before a run. It really depends on how often you use the bike but this task is made easier by the addition of a sump plug. Running it with the amount of oil in your picture will be OK but there will be oil coming out of the breathers etc until it is all returned to the tank and may be difficult to start, also likely to smoke a bit.

[Martin K]

Thanks Roger

Thanks to your excellent sump conversion from Drags, and the whole sump plug easy thing, I’ll go with the option to drain it down before a ride. At least I know that in the intervening periods, the internals will be bathed in oil, preventing any internal corrosion/sticking etc.

Cheers

Martin

[robjameson]

It is a little known fact that the Huntmaster engine has an anti drain valve built in to its crank cases. So little known that it is often forgotten about during a rebuild and subsequently dirty and not correctly operating.

This may be worth checking, were it not for the fact you would need to split the crank cases again!

[Martin K]

Thanks Rob

The little one in its own gallery on the right hand case? It was stripped out and cleaned during the rebuild. It could be that it’s not working at all/properly. As you say, though, getting at it would require deep surgery. I’m not sure I’ve got the stomach for that again - I’d rather ride it if I can! So possibly have to stick to draining it before each trip out!

The joys, the joys….

Martin

[ken-drink]

there is another way, you can convert it to the A65 type which means removing the oil pump and doing a mod to the oilways, can be done in situ but have to careful to get all the swarf , it is a well documented mod for the BSA A7/10 , ideally done when rebuilding the engine.
an expensive but easy fix is to fit the srm oil pump, fitted one to my A7 and it does not wet sump.

[simon.holyfield]

there is another way, you can convert it to the A65 type which means removing the oil pump and doing a mod to the oilways, can be done in situ but have to careful to get all the swarf , it is a well documented mod for the BSA A7/10 , ideally done when rebuilding the engine.
an expensive but easy fix is to fit the srm oil pump, fitted one to my A7 and it does not wet sump.

Could you share a link to some information Ken?

[ken-drink]

yes there is a lot of info on https://www.a7a10.net/forum/ including some drawings as how to do it, i will look for the exact topic and post it later.

[ken-drink]

this is one of several posts on the topic https://www.a7a10.net/forum/index.php?topic=13668.0 with pics and drawings

[simon.holyfield]

this is one of several posts on the topic https://www.a7a10.net/forum/index.php?topic=13668.0 with pics and drawings

Excellent thanks Ken.