Cheap & easy solution for wet sumping problem

maylar

VIP MEMBER
Joined
May 13, 2007
Messages
3,859
Country flag
I put one of these sump plugs in for when the ride sits too long.
I look in the oil tank, if the oil level is down too much I'll remove the smaller magnetic plug, drain some oil out, put in tank and kick away. Only takes minutes to do.
06-7281_480x480.jpg

Who is the best source for those?
 
Joined
Apr 22, 2020
Messages
807
Country flag
Joined
Nov 26, 2009
Messages
2,603
Country flag
When considering reed valves or drain plugs - think about reliability. In racing you are required to tie wire the drain plug and for good reason. The more screws and parts you have down there to unravel - the more likely that something is going to come loose and leak oil onto your rear tire. Keep it simple - the fewer parts the better.
 

Conrad

VIP MEMBER
Joined
Jun 3, 2020
Messages
54
Country flag
I'd like to pose a dumb question.

My (new-to-me) '73 Trident, in the workshop manual says before starting to kick/turn it over with ignition off to pump some of the oil back into the oil tank. As my '72 Commando doesn't have a convenient way to drain oil (after the fact) why can't I do the same thing (get my exercise and kick over the bike for a few minutes to pump some of the oil back into the tank)? Or are the engine case pressures different between the two bikes that even kicking over causes the problem Jim is attempting to avoid?
 

NickZ

VIP MEMBER
Joined
Oct 31, 2018
Messages
331
Country flag
1. My 72 Commando has the small sump drain plug on the bottom. Easy to drain the sump.
2. I doubt if kicking it would blow the seal, but if there is enough oil in the sump to cause hydraulic lock, maybe. But the breather would seem to me to be path of least resistance for the pressure.
 

ashman

VIP MEMBER
Joined
Jul 11, 2010
Messages
3,993
Country flag
Just ride it regularly instead of letting it sit to long, instead of looking at it ride it, so simple.
 
Joined
Nov 26, 2009
Messages
2,603
Country flag
I keep hearing the term "hydrolock" being repeated on this forum. But if you don't seriously overfill the oil tank, and then let it all drain into the sump - you will never have hydrolock. Maybe if all your oil was in the sump and then you filled the oil tank again before starting - and later parked the bike long enough to let all that extra oil drain into the sump - perhaps then you could experience hydro lock.

You just have to remember how much oil was in the sump before you parked it. Then just start it again as normal and check the oil level again later.
 

mdt-son

VIP MEMBER
Joined
Jan 19, 2012
Messages
1,187
Country flag
I'd like to pose a dumb question.

My (new-to-me) '73 Trident, in the workshop manual says before starting to kick/turn it over with ignition off to pump some of the oil back into the oil tank. As my '72 Commando doesn't have a convenient way to drain oil (after the fact) why can't I do the same thing (get my exercise and kick over the bike for a few minutes to pump some of the oil back into the tank)? Or are the engine case pressures different between the two bikes that even kicking over causes the problem Jim is attempting to avoid?
See #24 in this thread. If you don't mind the exercise, leave the ignition plugs in.

-Knut
 
Joined
Nov 26, 2009
Messages
2,603
Country flag
I'd like to pose a dumb question.

My (new-to-me) '73 Trident, in the workshop manual says before starting to kick/turn it over with ignition off to pump some of the oil back into the oil tank. As my '72 Commando doesn't have a convenient way to drain oil (after the fact) why can't I do the same thing (get my exercise and kick over the bike for a few minutes to pump some of the oil back into the tank)? Or are the engine case pressures different between the two bikes that even kicking over causes the problem Jim is attempting to avoid?
The trident doesn't have the same problem as the Commando because the Norton pistons both come down at the same time whereas the Trident has each of the 3 pistons descend one after the other so you don't get the same pressure build up and won't blow a seal. The Norton might blow a seal when kicking over if its way overfilled with oil and the sump is nearly full. I doubt you will have a seal blowing problem with the Trident.

As far as resistance to spinning the crank goes - a winter cold Norton is pretty bad wet sumped or not. I haven't noticed it being than resistant in the summer - wet sumped or not - but it gets bloody hot in the Calif summer and your bike is already warmed up before its running.
 
Joined
Jan 12, 2019
Messages
171
Country flag
Who is the best source for those?
Andover Norton. They want about USD 35 and I'd guess around 10-15 bucks shipping (5 days in my experience). If you can find it cheaper in the states, let us know. I'm planning on adding one or three to my next AN order.
 

maylar

VIP MEMBER
Joined
May 13, 2007
Messages
3,859
Country flag
Andover Norton. They want about USD 35 and I'd guess around 10-15 bucks shipping (5 days in my experience). If you can find it cheaper in the states, let us know. I'm planning on adding one or three to my next AN order.
Should have gone that way. Prices in the US seem to be in the $70 range. I ordered one from CBS.
 

elefantrider

VIP MEMBER
Joined
Apr 6, 2013
Messages
1,109
Country flag
The main problem I have found with starting an old wet-sumped bike is the potential for fouling spark plugs.

Also with a full sump, there are more areas the oil can leak from the case to the floor.

Aside from those factors, I don't worry about it.
 
Last edited:
Joined
Jun 23, 2017
Messages
7
Country flag
Hello
I'm new to Nortons. Background is with Laverdas and 70'sTriumphs.
I have a mk3 850 which I need to 'finish off' with guards, exhaust, etc. I've seen it running before I bought it about 7 months ago.

Following the conversation about wetsumping I thought I better remove the small bolt at the bottom of the cases. I was dumfounded to see over 2 litres (1/2 US gal?) of oil drain out. Do I need to have concern about some of that oil having run into the chaincase?

I'm going to read this thread thoroughly and consider options. The bike will be a few more months before its running. I'm waiting for new guards to arrive in NZ from UK.

Great forum guys.
Andre
 

Onder

VIP MEMBER
Joined
May 11, 2010
Messages
3,101
Country flag
I take the small drain plug out of the bottom of the crankcase if the bike has been sitting more than a week. Although
the Comstock sump breather will empty the bottom pretty quickly and provide a relief against blowing out a crank seal, I find
it much easier to kick over if I drain first. It isn't a big deal.
 
Joined
Mar 7, 2020
Messages
1,985
Country flag
Hello
I'm new to Nortons. Background is with Laverdas and 70'sTriumphs.
I have a mk3 850 which I need to 'finish off' with guards, exhaust, etc. I've seen it running before I bought it about 7 months ago.

Following the conversation about wetsumping I thought I better remove the small bolt at the bottom of the cases. I was dumfounded to see over 2 litres (1/2 US gal?) of oil drain out. Do I need to have concern about some of that oil having run into the chaincase?

I'm going to read this thread thoroughly and consider options. The bike will be a few more months before its running. I'm waiting for new guards to arrive in NZ from UK.

Great forum guys.
Andre
If I'm reading this correctly the bike has not run for 7 months? If so then it's way too early (or should that be late?) to start worrying about the amount of oil drained down. Before next start up drain both sump, oil tank AND chaincase, replenish all with the recommended amounts of your preferred oils (opinions vary :) )... then with 'regular' use you'll find to what extent (if any) your oil migrates and whether it's worth worrying over.
 
Top