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Wet sumping question
Posted: Tue Jan 11, 2022 11:13 am
by chogger
I am soon to be the owner of a 1962 G3,I know these bikes can suffer from wet sumping, my question is do I have to remove the sump plug to drain it after the bike has been stood for a while or can I rely on the oil pump to return the oil to the tank
Re: Wet sumping question
Posted: Tue Jan 11, 2022 11:31 am
by Duncan
Its one of those "it depends" replies.
If your oil tank is empty then yes as the engine can hydraulically lock and you probably have a primary chaincase full of oil too, if the oil level has dropped by an inch or so then no the pump will deal with it quite happily, its a judgement between the two.
To add some context wet sumping is more a malady for the twins and singles do not suffer to the same extent so in theory you should not have a problem, there is also a theory that if he bike is left on the compression stroke it is less of a problem, never tried this as I haven't really had a problem on my 350 coil ignition single.
Re: Wet sumping question
Posted: Tue Jan 11, 2022 6:48 pm
by jackstringer
My G3LS '61 does it at random times, been sitting for 2 years and have no issue, left for a month and its dropped a few inches and when I try to start it it wouldn't kerfufff. So at the weekend I will drop the oil, refill and start her up. I have heard people remove the oil or fit taps to the pipes but therein lies a ruin of a good engine.
Re: Wet sumping question
Posted: Tue Jan 11, 2022 9:18 pm
by Taid
When I bought my 16ms a couple of years back, it had a tap in the oil feed from the tank to prevent wet sumping, (and a piece of coloured cord to use as a reminder, which served its purpose) ..
I decided there must be a better way and after some checking, I found I could attach a wire to the magneto which would short the contacts. I replaced the existing oil-feed tap with one having an attached switch, and it is now wired such that I can't start the engine unless the feed is open. Also acts as an anti-thieving gadget.
If a bike has coil ignition, you can connect the switch on the tap in series with the ignition switch ..
Re: Wet sumping question
Posted: Wed Jan 12, 2022 11:33 am
by alanengineer
Its not a big job to empty the crankcase if you leave the bike for a while. One of my bikes is as good as gold and can be left all winter. Another cannot be left longer than a month and lets me know i have ignored her by not starting until i empty the crankcases.
Its all good as it serves for us to get down and check for loose nuts and bolts every now and again
Re: Wet sumping question
Posted: Fri Jan 14, 2022 7:49 pm
by JARO
Taid wrote: ↑Tue Jan 11, 2022 9:18 pm
When I bought my 16ms a couple of years back, it had a tap in the oil feed from the tank to prevent wet sumping, (and a piece of coloured cord to use as a reminder, which served its purpose) ..
I decided there must be a better way and after some checking, I found I could attach a wire to the magneto which would short the contacts. I replaced the existing oil-feed tap with one having an attached switch, and it is now wired such that I can't start the engine unless the feed is open. Also acts as an anti-thieving gadget.
If a bike has coil ignition, you can connect the switch on the tap in series with the ignition switch ..
Can you paste the link to this tap?
This is my protection for the tap ,a piece of belt on the starter.
Re: Wet sumping question
Posted: Fri Jan 14, 2022 9:51 pm
by Taid
Bought it from Feked .. 2 types ..
open circuit when tap open ..
Open circuit when tap closed ..
I've got the second .. feed all my electrics through it .. so nothing works when tap closed .. ..
believe there may be others ..
Re: Wet sumping question
Posted: Fri Jan 14, 2022 10:53 pm
by Duncan
Taid wrote: ↑Fri Jan 14, 2022 9:51 pm
believe there may be others ..
Indeed there is, has any one tried:
https://shop.kingpincomponents.co.uk/mi ... out-switch ?
Re: Wet sumping question
Posted: Sat Jan 15, 2022 9:11 am
by century
yep do what alanengineer wisely stated ,simple