After rebuild start up!

Information relating to the Matchless G3 or AJS Model 16 350cc Heavyweight
NaughtyNetley
Posts: 85
Joined: Fri Dec 28, 2018 12:09 pm
Location: Cornwall

After rebuild start up!

Post by NaughtyNetley »

I've a couple of little things to do on the G3 but may be ready to start it later today, if not it'll be mid next week due to work.
Any sage advice as my much more knowledgeable friend is in Australia at the moment so I'm flying blind.
Mick D
Posts: 2886
Joined: Mon Mar 24, 2014 5:44 pm
Location: Aberdeenshire

Re: After rebuild start up!

Post by Mick D »

Hi

Assuming it hasn't wet sumped - pour about 100ml of oil into the rocker box through the inspection cover, remove the oil cap, tickle the carb and give it a go. (Have a fire extinguisher to hand).

If it starts keep it running as slowly as it is happy with using the throttle and watch for a return flow in the oil tank, this should happen within the first minute or so, (but don't panic if it takes longer). If there's no return after 2 minutes I'd stop the engine and let things cool down for 15 minutes and re-start again and watch for a flow for a couple of minutes, if you still don't have a return flow start being concerned and post back.

While you're waiting for a return flow keep having a look around the engine for oil or fuel leaks, being prepared to stop the engine if required.

Fingers crossed ;)
NaughtyNetley
Posts: 85
Joined: Fri Dec 28, 2018 12:09 pm
Location: Cornwall

Re: After rebuild start up!

Post by NaughtyNetley »

Thanks Mick, unfortunately I find the battery I bought has lost all its charge and my trickle charger refuses to do anything so this will now have to wait until next week.
Other things to do today.
User avatar
Pharisee
Member
Posts: 1126
Joined: Tue Mar 15, 2016 8:51 pm
Location: Lincolnshire UK
Contact:

Re: After rebuild start up!

Post by Pharisee »

Check this out...

I'm from the Fens.... Gimme six.
User avatar
spookefoote1956
Member
Posts: 1836
Joined: Mon May 01, 2017 7:32 pm
Location: Wales Innit

Re: After rebuild start up!

Post by spookefoote1956 »

Is it coil or mag?

Just seen your profile. Coil. Charge the battery up. :beer:
Hail Joe Lucas ............ Prince of Darkness!
All my bikes are original........ to me!
"Creativity is your intelligence having fun" Albert Einstein
Dixter
Posts: 102
Joined: Mon Oct 02, 2017 8:27 pm
Location: Seattle area, WA USA

Re: After rebuild start up!

Post by Dixter »

Hi Neil, a few other pointers. There is some advantage in adding the initial fill of the oil tank, a few hours before starting, to allow gravity to pull oil thru the line and flood the oil pump inlet.

If the oil tank was filled more than a few weeks ago, I'd encourage you to check the crankcase to ensure the bike had not “wet sumped” and over filled with excess oil. If you decide to check the crankcase, do this before pouring oil down into the rocker box as recommended by Mick D.

If the bike has an oil filter in the oil tank, remove the cover to the filter chamber, and fill the compartment till the filter is saturated and the chamber brimming with oil. Replace the filter cover.

Please note, the oil pumps on these bikes are agonizingly slow. If the filter compartment is dry, oil return seen in the tank filler can be closer to five minutes. This is normal, but your heart and head will not think so.

Ciao,
DC
Dick Casey
The RideNut
User avatar
clive
Member
Posts: 5657
Joined: Mon Jan 01, 1990 12:00 am
Location: LONDON UK

Re: After rebuild start up!

Post by clive »

A while ago i put up this post.

"The question of how long is reasonable to wait for the oil to start returning in the oil tank when rebuilding a heavyweight single seems to come up a lot. As I was trying to seal some major leaks from both pump plates on my 55 G80 engine I thought I would time things.
So I drained the oil tank, then cleaned the oil tank filter during which operation probably half the oil in the filter housing was removed/spilt. I then drained the sump followed by replacing both pump plate gaskets. Despite emptying the oil, both ends of the pump leaked copious amounts of oil whilst the gaskets were replaced.
So in all pretty much like a newly rebuilt engine in terms of little oil in it, except I knew there was still plenty of oil around so did not do what I usually would with a newly built engine (prime the oil by pouring about 4 fl oz down each pushrod tube to make sure the bottom was oiled and which would of course filter through and prime the sump).
But without any oil added how long did it take? Well after 7 minutes of running the engine on a fast tickover even I was beginning to worry though I was sure all was well. The oil level in the tank was clearly dropping but only slowly so not that obvious. Finally after about 8 and a half minutes the oil began to pulse out of the return. The level in the oil tank had probably dropped by 1/3 as the sump filled, the return pocket housing the filter filled, and the oil pipes to the rockerbox refilled.

It would probably take longer on a slow tickover."
clive
if it ain't broke don't fix
User avatar
Pharisee
Member
Posts: 1126
Joined: Tue Mar 15, 2016 8:51 pm
Location: Lincolnshire UK
Contact:

Re: After rebuild start up!

Post by Pharisee »

The return oil pump piston is 1/2" diameter and it has a stroke of 1/8". There are 16 teeth cut into the pump piston and it's a two start worm driving it. That's one cycle of the pump every 8 cranckshaft revolutions. At best, considering the way it works, covering and uncovering holes, it's probably only about 50% efficient. Without going into the simple maths, that's about 25cc's per minute at 1000 rpm.
I'm from the Fens.... Gimme six.
NaughtyNetley
Posts: 85
Joined: Fri Dec 28, 2018 12:09 pm
Location: Cornwall

Re: After rebuild start up!

Post by NaughtyNetley »

spookefoote1956 wrote:Is it coil or mag?

Just seen your profile. Coil. Charge the battery up. :beer:

Only have one of those digital chargers which won't do anything to a flat battery. After some poor advice involving a brief connection to a 12 volt battery, it took charge but has actually buggered it up, sigh. New one purchased today. At least they're only £14.......
NaughtyNetley
Posts: 85
Joined: Fri Dec 28, 2018 12:09 pm
Location: Cornwall

Re: After rebuild start up!

Post by NaughtyNetley »

Pharisee wrote:Check this out...


That looks like it had a complete re-build ;)
Locked