1973 850 commando....

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Cleaning a fibreglass tank well enough to take sealant is a bit more difficult than steel. What do Casewells recommend for fibreglass tanks?
 
Ok.... my friend thats working on it just told me the tank is metal!!..When I pounded the outside it felt heavy like fiberglass..but he put a magnet on the outside and on the inside hump that the frame sits on and it stuck!!! was there a metal inside layer or something? the filler neck is metal......I was 99% sure it was not metal!! anything I'm missing???
 
Good news that you have a steel tank, it was a major aground on my Fastback to source and then seal an Indian made tank.

Just ensure that Casewells warrant that their sealant is proof against ethanol as some earlier sealants failed with the introduction of ethanol.
 
If the tank is steel and clean Im not sure it needs a sealant. Check carefully first but this may avoid an expense and a lot of agro. I have an original steel interstate tank, use pump fuel and have no issues whatsoever.
 
Ok.....update...a little more work has been done...but lots more needed...my intent is to get it running and try to keep it original....but have a couple of problem areas..we are rebuilding the front master cyl..and caliper...I need a brake switch(just see aftermarket..)..my original key switch is non functional..if we jumper it lights start working?..is there a was to "free up" this switch or should I purchase new?A bigger issue is when we cut the wire holding the exhaust nuts we saw that the head is somewhat stripped..the nut threads appear fine..any solution here short of getting a new head? Also both spark plugs were mismatched..a b7es..and a br8es...manual shows b7eb-11..which should we use?...Thanks in advance...
 
keso said:
Ok.....update...a little more work has been done...but lots more needed...my intent is to get it running and try to keep it original....but have a couple of problem areas..we are rebuilding the front master cyl..and caliper...I need a brake switch(just see aftermarket..)..my original key switch is non functional..if we jumper it lights start working?..is there a was to "free up" this switch or should I purchase new?A bigger issue is when we cut the wire holding the exhaust nuts we saw that the head is somewhat stripped..the nut threads appear fine..any solution here short of getting a new head? Also both spark plugs were mismatched..a b7es..and a br8es...manual shows b7eb-11..which should we use?...Thanks in advance...
Click to expand...

Uncrimp, clean, lubricate. No drama.
 
Also both spark plugs were mismatched
I can see how one or the other might be mis-matched. But both? Gosh. :wink:
NGK BP7ES is a good place to start. Depending on what ignition you have, you might want resistor plugs BPR7ES. You cd spend more for BPR7HIX or BPR7EIX, if you think it wd help.

any solution here short of getting a new head?
Yeah, getting a new head wd be expensive. If the head is otherwise good, the exhaust threads can be repaired.. If it were me, I'd send it (with the nuts you plan to use) to someone expert like Jim Comstock, who wd evaluate the item in all respects (such as valve guide wear), and repair the threads as/if needed.
 
ok..ballpark on the thread fix?....need to tackle this problem first as it may take all my project money.....
 
keso said:
ok..ballpark on the thread fix?....need to tackle this problem first as it may take all my project money.....
Click to expand...

Oh!, say $100 plus shipping. But while the head is off, get it checked out! No point in reinstalling a head that needs rehab, and that could cost $500 if done right.
 
Keso, I don't think you told us how many miles are on this engine?
If it's 20K or so, new threads for the head might be all you need. But at 38k, mine was knackered; burned oil, blew smoke, was a bit*h to start and tune, needed new valves, guides, springs, etc. Not cheap, but not horrible either, had to be done. Along with a bore to 20 over, new pistons and rings, now she's a happy camper.
 
Mr. Rick said:
......But at 38k, mine was knackered; burned oil, blew smoke, was a bit*h to start and tune, needed new valves, guides, springs, etc. Not cheap, but not horrible either, had to be done. Along with a bore to 20 over, new pistons and rings, now she's a happy camper.
Click to expand...
I might add that Comnoz will also do things like check the volume of both cylinders. Something I now believe the factory didn't keep such a close eye on.
 
+1 on sending any critical repairs to Jim Comstock.

While any good machinist may be able to do rethreading a spark plug hole or some other simple machine work, just getting Jim to look at your head and give it his "OK" has a value that other machinists less familiar with nortons don't have... I had a single lifter delaminate on my commando without damaging the cam. Jim had me send him that pair of lifters so he could match them up to the lifter tunnel in one of his own spare barrels, which allowed him to fit the new lifters he was sending me to my barrels from 1000 miles away... He also sent me a tiny tube of assembly lube to make sure the lifters seated properly. He's a F*ckin' smart guy... who cares about getting shit right.

I also know a local machinist who is amazing. He's a motorcycle guy, but not a norton guy. I would give him most of generic machine work I might have because he's local to me, but some machine work, like threaded inserts in the exhaust port, or head work are best left to machinists who have that next level of intuition that only comes from being a "norton guy", like Jim....
 
Thanks for the insight..I have already contacted jim...300 for the inserts..the bike has only 9500 miles...every piece original...but the exhaust threads are not good..the nuts were wired tight..when the wire was cut they fell out...I know the bike sat for along time indoors..my mechanic friend is going to check compression to see what shape the engine is in...hate to do too much work..but want to do enough!!...insights?..
 
300 sounds like a lot to me, but like my mother before me (who at 92 had fallen behind the times finance-wise by almost a whole decimal point) I consistently underestimate modern pricing.
You're on the right track. Find out discreetly what others charge if you can. And pay NO attention to someone who will not guarantee the work.

Good thing I wasn't there to see those wires being cut. I'd have been laughing out loud, and then feeling like an ass for finding your bad fortune humorous... :o
 
Mr. Rick said:
300 sounds like a lot to me, but like my mother before me (who at 92 had fallen behind the times finance-wise by almost a whole decimal point) I consistently underestimate modern pricing.
You're on the right track. Find out discreetly what others charge if you can. And pay NO attention to someone who will not guarantee the work.

Good thing I wasn't there to see those wires being cut. I'd have been laughing out loud, and then feeling like an ass for finding your bad fortune humorous... :o
Click to expand...

$300 sounds like good value to me. Lifetme fix. Priceless.
 
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