My 1971 Norton Commando

Really cool.
Keep the original paint.... My opinion.
If you want nice paint get a new tank and paint it. I found out the hard way that original will be more valuable.

Why don't they want you to use a gasket between the case and jug base.? Please explain.

Proberly worn. just had this issue...bush tight top and bottom...slack in the centre.

Dennis C said:

Front end is back together, but I have some stiction in the fork sliders, the bottom bushing on the fork tube is sticking when depressed, I'll take the forks back off and try the old fork tubes to see if they stick, I do not remember that they did. If they are smooth I'll mike the bottom bushing and may replace it with the old one. only sticky on one fork.

Once I get this sorted it is on the electronic ignition, I think I will go for the power arc from Old Britts.

What oil is every body using. regular or synthetic, and which has the best Z content. Motor is still dry, so I have to add fluids every where.

Fork oil?

Thanks Dennis

Click to expand...

As far as I can tell the stiction was caused by a slight miss alignment of the forks in the triple crown. loosened everything and compressed the forks with the brake on and then double checked alignment, all now seems to go up and down smoothly. After tracing the wiring and comparing it to the wireing diagram the head lights now work

New AGM battery, new fuse holder installed and as near as I can tell all the electrics are working. Eliminating the old boyer, coils, condensers and other bitts related to the old system got rid of a lot of excess wiring and looks like it will be a much simpler installation and system

I ordered a Power Arc ignition from old britts and it should be here when I get home from work Hopefully I will be starting it this week end.

Dennis

Well it half started, Installed the Power arc ignition and as soon as the throttle was at the right position it started, adjusted the throttle stop screws and and after a bit of fiddling I had a reliable idle.

Problem when I tried to adjust the idle mixture screws it was only running well on one side. did the plug pull and set the mixture be tween lean and rich, put the plug lead back on and pulled the other side turning the idle mixture all the way in or out 4 turns and no effect.

I checked the temperature of the exhaust pipes where they come out of the head and the side that runs well is about 240* the side that is not running so good is 90*

With the plug lead off the poor running side I tried to give it some throttle and it coughed and died. Put the leads back on and pulled the cold side and it had good throttle response with the other side

I did a very short ride and with any throttle it is only running on one side. I am using twin Amal carbs that I had sent in for rebuild

The carbs are in sinc as close as I can get so that they both start to move at the same time and the throttle stop has them at the same level

Any ideas please

Dennnis

Poor side idle jet plugged ?

Similar situation with my '71. New Amal carbs; would not fire evenly or at all on left side. A: mixture too lean on that side. 1/4 turn in (reducing idle air flow) and it fires up and runs great.

Hope this helps.

BC

Success

After doing some more testing I determined that it was running very rich at idle and the idle mixture needle made no effect on how it ran. The plug was black and sooty

Checked the compression and it was 150 lb and 155 lb From what I have read that is pretty good

I did several searches here on the forum and removed the offending carb. The first thing I found was that the needle had slipped. the clip was still attached and it was half way up in the throttle slide. I completely disassembled the carb removed the jets and blew out all the air passages. (found out that if the idle mixture does not work it is plugged and will run rich.) put it all back together and carefully put the slide back in making sure the clip was still attached and seated correctly. Not my bad as I had shipped the carbs off and had them professionally rebuilt. Not a huge deal but still frustrating.

Started up 2nd kick and I could tell it was running on both cylinders. decided to take it for a ride and test it out. first thing I noticed is left side shifting and right side breaking does not work on a commando. I also forgot how light the bike is. The new veneer iso's work great no vibration. Still a little rich in the mid range, but holding the clutch and cranking the throttle a little cleared it right up. Idle a little low as I had to do the throttle blip at the stops. Short ride just a couple miles. but enough to tell that the rest is just tuning and sorting.

Rode it around the neighborhood so never got out of 3rd gear. very easy on the throttle

I am happy. very happy

Dennis

about 30 miles today mixed riding, some on the highway(all the way up to 50) some in town and a little on some easy curve,

I need to still do some work, it is popping on the left side when I roll of the throttle, is that a mixture issue?








Dennis

Check air leaks, intakes to exhaust exits. Possible HT lead leak too.

Maybe just try and screw the left side air jet out 1/4 turn

A very slightly leaking exhaust will cause popping back on overrun. If you haven't used an exhaust sealer then it might help. I find it helps, but don't get any inside the header. Get on and ride it straight away as well..

Dereck

The Power Arc was an easy installation and after sorting carb problems it has been excellent.. 2 or 3 kicks cold and first kick hot

very smooth through rev range and solid idle at 1000 rpm

I installed new veneer ISO's and there is no noticeable vibration from 1000 to 3500 rpm, have not pulled past that yet

suspension is firm, and steering is quick, I have been riding easy new pistons and rings and 43 year old tires ( they will be the next purchase) I am going to have to go slow in pushing any limits I have no desire to have a flat or blow out

No idea if it will have a high speed wobble or weave but very solid at the 50 I have been doing.

About breaking in, low end and transmission are all original new pistons rings valves, guides and springs.

I had thought to break it in like a new bike, but I have read that with pistons and rings I can/should push it harder and sooner. short bursts of nearly full throttle then back off

What is the advise from the forum

Dennis

You have about 15 minutes to seat rings optimally. Warm it up, then use the throttle and load the rings. Google Motoman on engine break-in
Doug

it is not that your old tires lack tread, it is that they are hard and cracking, and thus dangerous

We all beg you, get new tires, tubes, and rim straps.....

New tires will be on the way soon.

And after reading the motorman break in article it may be to late to have ask the question. I have about 130 miles of easy riding keeping the rpm under 3500 No loading and varying rpm and gears. Not going to take it down to put new rings in but I will switch to the motorman schedule even if it is to late. sounds like it wont hurt hope it will help.

I hate it when I do not know enough to know what I do not know.

Dennis

And the next test is installing the new R 0990 K&N air filter. It jams against the old rear air filter back plat. Looks like I need a bigger hammer and screw driver to get it in.

Any one have better ideas or experience

Thanks

Dennis

Dennis C said:

And the next test is installing the new R 0990 K&N air filter. It jams against the old rear air filter back plat. Looks like I need a bigger hammer and screw driver to get it in.

Any one have better ideas or experience

Thanks

Dennis

Click to expand...

Get rid of the old back plate.
Seriously, are you going back to using it again.

Dennis C said:

And the next test is installing the new R 0990 K&N air filter. It jams against the old rear air filter back plat. Looks like I need a bigger hammer and screw driver to get it in.

Any one have better ideas or experience

Thanks

Dennis

Click to expand...

They make a K&N filter for the original ham can air box if you want the stock look (old Britts). I'm not sure why so many people get rid of them. If you remove the rubber boots first and install them last it's easy access. That air box is a defining feature of the commando IMHO.

hobot knows why his perfectly good fairly fresh properly deformed by air box tight seating k&n filer hi up on a shed wall nail is available for cheap+shipping. Me and Wes's reasons do not concern the majority of others' conditions.