Not open for further replies.
Oct 11, 2005
Starting to get intermittent starting using the electric start on the MK3. Noticed thin whisps of smoke comming from between the body of the solenoid and the top plate.

Got a dodgy leg from sideswipe years ago so quite partial to the electric boot. Is the solenoid reparable or is there a better unit to replace it ?

If the solenoid is energizing, then it's probably not that. If the solenoid will not engergize, but you can spin the starter by shorting the primary leads, then you need to replace the solenoid. I have seen Ford solenoids and garden tractor solenoids used. I have never had to replace a solenoid, so I can't say that these were improvements over the stock Prestolite unit.

If the starter is just reluctant to turn, then as Greg suggests, start with the cables. I chose to make mine using welding cable, soldering all the ends. Dynodave's cables are just as good if you don't want to mess with making them.

If this doesn't help (and you have a good battery) you have two choices. One is to find a Harley field coil (4-pole), and convert your starter using your armature and end caps and new bearings and seals. I have done this using new brushes and it spins my 11:1 compression motor pretty easily. However, I had a new armature as well. Most armatures are pretty much toast by now.

The other option is Dynodave's starter conversion. This is probably the most economical and trouble free route unless your armature is in very good condition and you want to maintain a very stock look. This is a Japanese starter converted to work on the Norton. While I have no personal experience with this, the theory and reviews I have read makes this a logical choice.

Take the solenoid (once you've determined its bad) to a foreign auto parts store (maybe any auto parts store will do). The solenoid is almost identical to any number of older auto solenoids and will probably cost half what an "original" part costs. I had a Ducati Darmah that used the same solenoid and found a replacement for it that was for, as I recall an MG Midget.

As for the 4 pole conversion, most of the catalogs for harley parts have kits for the Prestolite sportster starters which are the same as the Norton except for the armature. So if your armature is good you could get the harley kit for a boost in starter performance and as Greg said don't forget the cables.

Without being totally familiar with the solenoid.. I can say confidently that the solenoids of the time (Correct me if I am wrong. ) were a metal bracket riveted to "a body ", be that metal or plastic /Bakelite.

Which ever ~ in a starter solenoid there is a "pull in" coil, and a"holding coil" ~ the first pulls a metal plunger, thus closing the contacts, a second coil takes over and 'holds ' the plunger and contacts as the primary coil draws a lot more current .

These little buggers DO ~ over years build up moisture and corrosion which may well account for smoke and erratic performance, and even smoke, after all , given it is the original unit it is getting on .

Personally . I know they can be serviced, with some effort. but simply put it probably easier and more effective to simply replace the unit .

As the other bloke's posts suggest , there are a number of possibilities, but ~

One effective simple test this a test lamp will give some insight.. by activating the starter and holding the test lamp of the first battery cable post and then the second, IF you're having solenoid 'resistance' problems the test lamp can very well show a notable difference in brilliance which will indicate contact deterioration !

Thanks lads for your suggestions. Took the starter off and 'ok wait for it' hooked it up to the t160 electrics. Spun like a gem. So the whispy smoke comming from the solenoid is the deciding factor.

I checked with British spares in NZ and a replacement is only $40 something NZ so i might go with that. I remember reading back in the 70's that a mini solenoid was the replacement along with new cables (Dyno Dave). But as Scooter suggests there may be others out there.

I have a feeling once i get the electrics sorted out the sprag is going to rear its ugly head :) The way my luck is going at the moment :)
Mate ~ while not wanting to throw water on your 'flame" ~ or be pandantic.. coz the starter 'spins over" ~ can be a tad different from being "under load" or churning over an engine.
(It 'can' get more complicated....)

BUT that aside.. most solenoids will do the trick.. just consider the size of the engine the related starter motor has to turn over.. it is really about 'current' draw.

The "Mini" solenoid was/ is always a good option.. if you have the space .. a cheap effective option ~

thanks for the feedback. I might be wrong but if it was failing under load it would do it all the time...but then that raises the question why is it intermittent anyway. Was fine today so that was good.

Was one of these lucky mornings. Bike started on ES...had shoved old fuel into the norton that the T160 had the shits with..started no problem...lots of rain but manged to get to and from work in between showers. Put money on a horse this morning and won $20.

Probably get a puncture tomorrow :)


Electrics can be fickle and erratic .. starters can free wheel just fine and fail under load.. but I don't want to rain on your 'day" ~

Same with solenoids. subtle raps or taps, with a spanner when they fail may be enough to put you on the right track ~ tapping the item may be enough to tell you which is the offender.. (At least you have a kick start to keep you going!)

I have to say you are fortunate with the fuel element too as I have to drain off the fuel from the Commando if it stands for more than two weeks ~ stick it in the car and put fresh in the bike !

As for betting tickets, back in the 1990s I was working as a security porter ,and in my night duties I was doing the rounds and in one corner of the hotel court yard, there was a spot that 'captured' litter.

This night there was several slips of paper and I picked them up and in the dark , put them in my pocket and thought nothing more, till I got home and emptied my pockets including tips into my tip jar.

I noted one of the slips was a betting ticket.

Several days later my partner and I were going to the local tavern and I thought I have nothing to lose so took it along. and presented to one of the girls behind the bar... it paid $70 + !!!

(Yeah . sure I ran an add in the local paper asking for the owner to come forward and claim the ticket ~ specially since it was in the dead heart of Australia's Red centre !!!!!!!!!!!!!!!)

A nice tip !!! :wink:
Not open for further replies.