1959 Dominator

seattle##gs

Joined
Oct 28, 2014
Messages
1,858
Country flag
I am working on a 1959 Dominator and have many questions.
A) is there an electronic ignition to fit in the distributor? It is already upgraded to 12V.
B) the oil pump is the 3 start type and does not appear to be returning oil. The sump had at least a quart in it, I looked inside the oil tank while it was runningand could not see anything returning. I cracked the return spigot on the tank and the oil flow was feeble. Since I am not familiar with the low pressure oil systems I am not sure what to expect. I am 85% sure there is something wrong with the oil pump and I will remove it next week and thoroughly check it. I removed the large sump plug and the screen was clean. I can also check the OPRV but that would not affect the return. If the oil pump needs replacing would it make sense to use the 6 start pump? along with Commando rocker spindles?
C) Did the engine breather vent to the ground or did it go up to the oil tank? The previous owner cut off the froth tower and wended in a patch.
D) Best GB sprocket to use. My Atlas rubs best with a 21 tooth but the dommie is only 600cc.
 
On my 58 Dominator the engine breather went to the ground. Never been a big fan of this. There isn't a froth tower on my 88 oil tank due to the way it sits in the frame. Check the oil pump gasket and replace it and the conical seal that might help. I changed my charging system over to 12v and the only thing I did was replace the bulbs and installed a Podtronic regulator.
John in Texas
 
If you decide to change to 6 start oil worm gear, along with the mating gear on the crank, it is not necessary, or advisable to change to the Commando rocker spindles. My Atlas has the 6 start gears and the low pressure rocker system; works fine.

If your oil tank had a froth tower, that is where the sump breather line went. There are two hose taps on the oil tank froth tower, one high, and one low. The low is for the sump breather, the high is the vent to ground.

The froth tower is a one inch tube .... you can easily replace the one the PO cut off. Check out the mod I did to my froth tower ..... https://www.accessnorton.com/NortonCommando/atlas-dommie-oil-mist-scrubber.16411/

That link also shows the hose taps on the tower.

Slick
 
Last edited:
I have 12v and distributor with a cheap Boyer points assist box. The ignition is vastly improved and points last indefinitely although get a bit oily and need adjusting still. I would like to lose the points but have not yet found a good replacement.The distributor is a weak point as you still have the mechanical advance and rotor arm /cap for which quality replacements are not readily availiable. I did try a magnetic trigger but could not get it to work at all!!. An early Commando points unit can be fitted with a Boyer and new double ended coil, but be carefull to get one that gives a good early advance or acceleration suffers. The very expensive BTH unit looks good. The 6 start oil system is too much for this motor and will drown the distributor and other problems ,been there, done it ,gone back to 3 start and carefully improved head oiling.A 650 pump with 3 start gears might be a good compromise, New pumps can be poor quality I hear. I have a froth tower and linked breather (with larger 3/8th) pipes . Works but short rides make condensation in the tank. Rear chain now needs regular oiling .
 
norton bob said:
I have 12v and distributor with a cheap Boyer points assist box. The ignition is vastly improved and points last indefinitely although get a bit oily and need adjusting still. I would like to lose the points but have not yet found a good replacement.The distributor is a weak point as you still have the mechanical advance and rotor arm /cap for which quality replacements are not readily availiable. I did try a magnetic trigger but could not get it to work at all!!. An early Commando points unit can be fitted with a Boyer and new double ended coil, but be carefull to get one that gives a good early advance or acceleration suffers. The very expensive BTH unit looks good. The 6 start oil system is too much for this motor and will drown the distributor and other problems ,been there, done it ,gone back to 3 start and carefully improved head oiling.A 650 pump with 3 start gears might be a good compromise, New pumps can be poor quality I hear. I have a froth tower and linked breather (with larger 3/8th) pipes . Works but short rides make condensation in the tank. Rear chain now needs regular oiling .
Click to expand...

Why wouldn't you run a magneto? Expensive for a rebuild or new unit, but dead reliable in my experience. Well, I guess reliable until they're not.

Interesting that I've now heard/read several times very recently about 6 start pumps being too much or unnecessary on these old motors, but previously the talk was all about improving the head oiling with volume, via pressure-feed, the 6 start pump, and plain spindles. What's changed?

What specific improvements to the head oiling are you referring to for the 3 start?

I'm very interested in this.
 
I have a couple of mags ,but at 73 and with a few health issues I need a motor that bursts into life with one lazy kick .A hot coil system is far easier to start as mags develop the power at high revs (and that's not important). The std low pressure head feed is not a consistant performer . By carefull experiment you can restrict the return to push more oil up to the head. I inserted a brass plug and drilled it out in stages till I got just enough oil (checked by looking into the exhaust valve area). The motor runs quieter with it. Appart from running the pump twice as fast as needed (wear) too much pressure in the system ,overworking the PRV and bathing the mag/dissy drive ,a 6 start wastes power and aeriates the oil.The bigger crank of the 650/750 may be able to use the extra oil with its drilled rods and they also need oil seals on the valves or suffer burnt valves, and better rings, I don't need all that. KISS.
 
Last edited:
norton bob said:
I have a couple of mags ,but at 73 and with a few health issues I need a motor that bursts into life with one lazy kick .A hot coil system is far easier to start as mags develop the power at high revs (and that's not important). The std low pressure head feed is not a consistant performer . By carefull experiment you can restrict the return to push more oil up to the head. I inserted a brass plug and drilled it out in stages till I got just enough oil (checked by looking into the exhaust valve area). The motor runs quieter with it. Appart from running the pump twice as fast as needed (wear) too much pressure in the system ,overworking the PRV and bathing the mag/dissy drive ,a 6 start wastes power and aeriates the oil.The bigger crank of the 650/750 may be able to use the extra oil with its drilled rods and they also need oil seals on the valves or suffer burnt valves, and better rings, I don't need all that. KISS.
Click to expand...


Kickstarter: Yes. Understood. I've got a long kickstart lever, similar to the RGM ultimate and starts easily with the AAU, but I can't kick it from the seat. Have to be off to the side as the longer throw is too much, and that's just a different set of issues with a bad hip and knee, etc...

Oiling: Hmm. Good to note. I've got an 88ss motor to build and I'd like to have a reliable motor, but it's nice to not make mountains out of molehills. Easy does it.
 
Build that 88SS, if its a good one it will be a brill bike,just need to be prepared to rev it more than you are used to. Mine spent its life with the valves bouncing. Great bike.
 
Is the oil tank the same from 1959 to 1966? It might be easier to pick up another oil tank.
I will stay with the 3 start. Need to find out why it doesn't want to return oil very well.
 
seattle##gs said:
Is the oil tank the same from 1959 to 1966? It might be easier to pick up another oil tank.
I will stay with the 3 start. Need to find out why it doesn't want to return oil very well.
Click to expand...

I think (think means not absolutely sure) the Dommie and Atlas oil tanks are the same. They are fairly easy to find, but some are in rough shape. Beware that the upper mount, the "L" shaped tab on the tank top, flexes from vibration and work hardens the metal of the tank roof, causing cracks and leaks. I have a fix for this should you need it.

Your oil return problem is your first priority. Have you rodded out all the oil return lines? Keep us posted on what you find.

Slick
 
Wideline and Slimline oil tanks are different. Slimline have the tower, Wideline have a flat top. Sounds like someone modified a Slimline to fit as mentioned above.

Scott
 
This is a wideline frame. If the wideline oil tank has no froth tower then how does it breath?
 
t ingermanson said:
Why wouldn't you run a magneto? Expensive for a rebuild or new unit, but dead reliable in my experience. Well, I guess reliable until they're not.
Interesting that I've now heard/read several times very recently about 6 start pumps being too much or unnecessary on these old motors, but previously the talk was all about improving the head oiling with volume, via pressure-feed, the 6 start pump, and plain spindles. What's changed?
What specific improvements to the head oiling are you referring to for the 3 start?
I'm very interested in this.
Click to expand...

6 start pumps were not officially fitted by Norton’s until mid-1966, although you could buy the 6 start gears to fit earlier bikes. According to my GREEN Norton workshop manual the oil block to the crankcase had bigger holes, plus a bigger hole union on the oil tank and the oil holes in the crankcase were drilled bigger. The oil holes on say the dynamo drive crankcases were much smaller-whether this had any effect on the oiling capabilities –I don’t know.
 
Last edited:
seattle##gs said:
This is a wideline frame. If the wideline oil tank has no froth tower then how does it breath?
Click to expand...

A standard Wideline oil tank has what I believe is a continuation of the oil return tube protruding from the upper backside of the oil tank. From what I can tell a hose ran from this to a metal tube fitted to the chain guard for chain oiling (and venting?). Perhaps someone can confirm this routing as I cannot find original pictures. I thought about making my own vent fitting on my 59 as I have plugged the described tube, but already had the tank painted and spotless inside. Will see how much a difference it makes once I get her finished. I would look for a correct Wideline tank as you go along sorting your oil return issue.
 
Bernhard said:
6 start pumps were not officially fitted by Norton’s until mid-1966, although you could buy the 6 start gears to fit earlier bikes. According to my GREEN Norton workshop manual the oil block to the crankcase had bigger holes, plus a bigger hole union on the oil tank and the oil holes in the crankcase were drilled bigger. The oil holes on say the dynamo drive crankcases were much smaller-whether this had any effect on the oiling capabilities –I don’t know.
Click to expand...


Good info. I was aware of the lower volume pumps on earlier motors, but not of the smaller orifices. Thank you. Might be worth starting a separate thread, so the OP can get his info without the distractions/my ignorance.
 
norton bob said:
I have 12v and distributor with a cheap Boyer points assist box. The ignition is vastly improved and points last indefinitely although get a bit oily and need adjusting still. I would like to lose the points but have not yet found a good replacement.The distributor is a weak point as you still have the mechanical advance and rotor arm /cap for which quality replacements are not readily availiable. I did try a magnetic trigger but could not get it to work at all!!. An early Commando points unit can be fitted with a Boyer and new double ended coil, but be carefull to get one that gives a good early advance or acceleration suffers. The very expensive BTH unit looks good. The 6 start oil system is too much for this motor and will drown the distributor and other problems ,been there, done it ,gone back to 3 start and carefully improved head oiling.A 650 pump with 3 start gears might be a good compromise, New pumps can be poor quality I hear. I have a froth tower and linked breather (with larger 3/8th) pipes . Works but short rides make condensation in the tank. Rear chain now needs regular oiling .
Click to expand...
The Commando boyer would require the entire aluminum housing as the points plate in the distributor is is a smaller diameter. The distributor fastens to a thick chunk of aluminum then bolts to the back of the timing case. If I removed both would the Boyer unit fit right in?
 
You either have to find a points unit as fitted to early Commandos or late Atlas and convert that with a boyer kit or you can get a Boyer kit to fit the Distributor and you will also need a double ended coil . the Dissy cap and leads are then left in position for looks only. If someone has fitted a 250 Jubilee tank return fitting (to improve head oiling) you can find the head flooded with oil and the oil does not get back to the tank much as it is effectively going in circles!, To fix this you have to re-size the tank fitting until a better balance is achieved.
 
Last edited:
Replace the maggie with a new Joe Hunt maggie and it will fire up with one kick everytime and are a lot more reliable than the old maggies, they will fire up on half a swing on the kicker, as for the oil pump you won't know whats wrong with it till you pull it out could need a rebuild or replace the rubber seal and gasket, as for the breather you can run it to a catch bottle or out the back.
My Dommie I am building has a Lucas compertion maggie with a bit more bang than a standard maggie but if it gives me troubles I be replacing it with a JH maggie, I run one on my 850 and had a earlier JH maggie on my old Triumph and never had any problems with them, always started on first kick everytime.

Ashley
 
norton bob said:
You either have to find a points unit as fitted to early Commandos or late Atlas and convert that with a boyer kit or you can get a Boyer kit to fit the Distributor and you will also need a double ended coil . the Dissy cap and leads are then left in position for looks only. If someone has fitted a 250 Jubilee tank return fitting (to improve head oiling) you can find the head flooded with oil and the oil does not get back to the tank much as it is effectively going in circles!, To fix this you have to re-size the tank fitting until a better balance is achieved.
Click to expand...
Andover sells the entire points unit new. It's not inexpensive. The parts diagram is useful.
 
update...I pulled the pump off the motor, surfaced the flat side on a sheet of glass, blew out everything with air. replaced the oil lines and now have a reasonable return flow visible in the tank. There was no gasket on the pump so I added that. Used the timing cover gasket from a commando and made up the difference with shims under the rubber cone shaped seal. There are special AN shims made to do this job if you weren't aware of that fact. I drilled the oil tank cap for an elbow fitting and that is receiving the crankcase pressure. Cheap and easy fix. It currently has dual Amals, it will have a single Amal this Sunday.
 
You must log in or register to reply here.
Back
Top