1972 commando rebuild

gortnipper · Jun 23, 2021

I would use a greased gasket and see how that goes.

BERT · Jun 23, 2021

gortnipper said:
I would use a greased gasket and see how that goes.

Thank you.

Fast Eddie · Jun 27, 2021

If it were mine I would try sanding the raised areas, with patience you should get close (or at least closer). I’d then assemble using a gasket as Gortnipper says as that will take up minor deviations as it is compressed.

BERT · Jun 28, 2021

Thank you to the Forum participants who share their knowledge, experiential learning, and humor. For this rebuild, the parts seem to be falling into place nicely and the e and is in sight for firing this puppy up. Jake the apprentice is sleeping on the cool floor, and he is always there to answer questions that arise about supper.

BERT · Jul 14, 2021

Well, tomorrow is a big day as this bike is assembled and ready to fire up. She is still on the table with fluids in as I can see leaks better(hopefully very few). Gas goes in tomorrow and I'll fire her up and go for a spin to bed the rings in.

Saber · Jul 14, 2021

Is that a bear sleeping next to the bike?

Larry S · Jul 14, 2021

BERT said:
Well, tomorrow is a big day as this bike is assembled and ready to fire up. She is still on the table with fluids in as I can see leaks better(hopefully very few). Gas goes in tomorrow and I'll fire her up and go for a spin to bed the rings in.

Good luck!

BERT · Jul 16, 2021

She started first kick and oil reached the tank in 60 seconds. Half way around a 15 minute loop she started to miss. Back home on the center stand the right cylinder would start to smoke at 3000rpm. The exhaust roses tightened another quarter turn.I am hoping retorquing the head fittings will resolve the smoke. I will check the plugs before I retorque the fittings . I am happy with the tracking, vibration, and everything else, I believe the issues that lead to this rebuild have been rectified. A big thanks to Forum members for all the support and shared knowledge so far to get this bike back on the road. Cheers, Dave.

BERT · Aug 1, 2021

Back at good progress today. Tightening the exhaust and retorquing the head didn't correct the misfiring. This past week was spent eliminating possible causes. Today the problem is narrowed down to a faulty podtronic unit (I think-input welcome). I found a 4 step test for it in a forum thread and there is no continuity in any test configuration given. I disconnected the Alton starter leads, taped them up and the misfiring is gone- the bike ran really well during a test run with the alternator disconnected. The Alton output is showing 33voltsAC at the leads at 3000rpm, is this acceptable? Before I replace the podtronic unit, the cause of the failure needs to be known. Any help at this point would be greatly appreciated. I also posted a thread requesting trispark help with more relevant details on this issue, The trispark is working fine as I checked it with the testing mode instructions. Thanks in advance.

gortnipper · Aug 1, 2021

BERT said:
Back at good progress today. Tightening the exhaust and retorquing the head didn't correct the misfiring. This past week was spent eliminating possible causes. Today the problem is narrowed down to a faulty podtronic unit (I think-input welcome). I found a 4 step test for it in a forum thread and there is no continuity in any test configuration given. I disconnected the Alton starter leads, taped them up and the misfiring is gone- the bike ran really well during a test run with the alternator disconnected. The Alton output is showing 33voltsAC at the leads at 3000rpm, is this acceptable? Before I replace the podtronic unit, the cause of the failure needs to be known. Any help at this point would be greatly appreciated. I also posted a thread requesting trispark help with more relevant details on this issue, The trispark is working fine as I checked it with the testing mode instructions. Thanks in advance.

Sounds like a bad Pod which needs replacing no matter the cause.

According to Alton, the alternator has a max 150 watts output with an average of 90 to 95 watts at normal cruising speed.

So, say 33v @ 3k = ~90w @ 2.72a. Doesn't seem right to me and the v output of the Alton seems high. The Pod is designed to short out your alternator coils when the battery charge target voltage of 14.2 is met, so losing 19v would not be happy for it to do. The Pod is rated anywhere from 12-20a depending on model.

https://www.bsaunitsingles.com/Archives/Technical_Info_sheets/Podtronics%20instruction%20sheets%20x.pdf

EDIT: The voltage output may be high due to no battery connected and therefore drawing no load to the rest of the system (ignition, etc) while running? I am only a electricky novice, so someone else would have to offer better commentary.

BERT · Aug 2, 2021

gortnipper said:
Sounds like a bad Pod which needs replacing no matter the cause.

According to Alton, the alternator has a max 150 watts output with an average of 90 to 95 watts at normal cruising speed.

So, say 33v @ 3k = ~90w @ 2.72a. Doesn't seem right to me and the v output of the Alton seems high. The Pod is designed to short out your alternator coils when the battery charge target voltage of 14.2 is met, so losing 19v would not be happy for it to do. The Pod is rated anywhere from 12-20a depending on model.

https://www.bsaunitsingles.com/Archives/Technical_Info_sheets/Podtronics%20instruction%20sheets%20x.pdf

EDIT: The voltage output may be high due to no battery connected and therefore drawing no load to the rest of the system (ignition, etc) while running? I am only a electricky novice, so someone else would have to offer better commentary.

Thanks for the link to the Pod data. That will be good help. I am a novice with electrics also. Each of my house wiring fixit screwdrivers are burnt to a point! By the way, have you listened to the e-rectifying alternating awesome band out of Oz called AC / DC? Cheers gortnipper and thanks.

BERT · Aug 6, 2021

This afternoon, I believe the rebuild has been completed. After a few first start up issues, which got corrected with vital help from this Forum, she runs beautiful, tracks straight and all the issues to cause this rebuild seem to be corrected. Now the fun part, to get some "smiles per hour" on her to prove it was a good successful project. A huge THANK YOU GUYS for all the knowledge you share and I will hopefully be able to help others the same.

Richard Tool · Aug 6, 2021

Well done Bert ! Now go out and be safe and enjoy it !

grandpaul · Aug 6, 2021

Watch yourself, mate!

Take care of that beautiful bike...

gortnipper · Aug 6, 2021

Well done, mate. Make hay while the sun shines!

Larry S · Aug 6, 2021

Nicely done!

Saber · Aug 7, 2021

Well done. BRAVO!

BERT · Aug 10, 2021

So far so good, the machine starts easy, doesn't drip too much, sounds awesome, runs in a straight line, being a first time Commando owner , I would say this one is a keeper. I went to the home hardware today and when I came out of the store, there were admirers gathered around it as they are rare machines around here, and I obliged the onlookers to hear it, once again, one kick and she roared to life, and with a smile from ear to ear, I am quite sure there was envy amongst some as I sped away.

cjandme · Aug 10, 2021

BERT said:
So far so good,......... there were admirers gathered around it as they are rare machines around here, and I obliged the onlookers to hear it, once again, one kick and she roared to life, ......

That's good to hear, many times murphy's law rears it's ugly head when onlookers are gathered around on start up.

grandpaul · Aug 11, 2021

cjandme said:
That's good to hear, many times murphy's law rears it's ugly head when onlookers are gathered around on start up.

The more onlookers there are, the more kicks it's probably going to take (seems to be a general rule)

1972 commando rebuild

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