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Heat the bores and give it a go. Let it cool.
Repeat.
Repeat.
73 Commando 850 help!
- Thread starter jzmax22
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A couple of heat guns being careful not to blister the paint.
concours said:
I agree 100%, and @ kommando, a lawn mower is not a Norton. You may get it to run but the rust that gets cleaned off the bores by the rings makes a great abrasive paste that will happily mix with oil and gnaw on all the turney bits in the engine. As your engine sat over time, it more than likely "wet-sumped", meaning oil in the oil tank slowly emptied into the engine itself. This may have actually protected the crank main and rod bearings, and by the way, being 1973 870 it already has what are called "Super Blend" main bearings. So nothing to upgrade to regarding those,,, if they are still good, but I do not believe they would continue to be so if this motor should be freed and run.
Getting it freed though is necessary to get the barrels off. A seized in the bore Norton I once encountered was freed by heating the barrels with a propane torch using MAP gas (hotter) and whilst still hot tapping the pistons with heavy hammer on a sized block of wood. A heavy hammer used lightly gives much greater oomph than a good whacking with a small one. And don't worry too much about the pistons either because you'll need to bore oversize anyway to clean up the pits and bring clearances back to spec. This, is of course, after the head is off. At this point preserving the barrel paint is a side issue. Good luck and where are you located?
@ concours - The "Kank" is still good, pavement fine. Have done it once on the Commando and once on the Speed T. This year?? -Pete
concours
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One more for "must be disassembled":
"I still had a gallon can of WD40 that was about 1/3 full, that my Dad left in his boat shed; I poured the cylinders full and let them sit a few day - no joy. I also had some ice maker cleaner from my A/C repair days, poured THAT in and let is sit a week - no joy.
Then I tried brake fluid for a few days, after removing the head. One pop with a hunk of 2x4 trimmed to fit in the bore, and the pistons slid to BDC.
I replaced the rings, gave the bores a quick pass with a ball hone, and rode that bike hard for a couple of years, mostly off-road. You can believe me or not, but it didn't smoke more than a whisp at start-up, and ran great."
"I still had a gallon can of WD40 that was about 1/3 full, that my Dad left in his boat shed; I poured the cylinders full and let them sit a few day - no joy. I also had some ice maker cleaner from my A/C repair days, poured THAT in and let is sit a week - no joy.
Then I tried brake fluid for a few days, after removing the head. One pop with a hunk of 2x4 trimmed to fit in the bore, and the pistons slid to BDC.
I replaced the rings, gave the bores a quick pass with a ball hone, and rode that bike hard for a couple of years, mostly off-road. You can believe me or not, but it didn't smoke more than a whisp at start-up, and ran great."
grandpaul
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Now for an opposite view, although tempered:
I bought a non-running '70 Bonneville rolling project with a stuck top end, I just sprayed WD40 in there and let it sit a week or so. I went to kick it, and gave it everything my 125 pound body had in it; it freed off. I installed the rockerboxes, completed the assembly & hand-wired the bare minimum with a 2MC capacitor. It started within half a dozen kicks and I rode the poop out of it over the years, mostly off-road here on our family ranch property cowtrails. It smoked, compression wasn't high, but it was pretty fast and always started if it had clean carbs and reasonably fresh plugs (it would oil foul them within about 1/2 tank of gas).
Sold it last year, refurbished a bit, still puffing a bit of smoke but starting right up...https://www.facebook.com/grandpaulz/videos/vb.100002393382787/964803770276060/?type=3
I bought a non-running '70 Bonneville rolling project with a stuck top end, I just sprayed WD40 in there and let it sit a week or so. I went to kick it, and gave it everything my 125 pound body had in it; it freed off. I installed the rockerboxes, completed the assembly & hand-wired the bare minimum with a 2MC capacitor. It started within half a dozen kicks and I rode the poop out of it over the years, mostly off-road here on our family ranch property cowtrails. It smoked, compression wasn't high, but it was pretty fast and always started if it had clean carbs and reasonably fresh plugs (it would oil foul them within about 1/2 tank of gas).
Sold it last year, refurbished a bit, still puffing a bit of smoke but starting right up...https://www.facebook.com/grandpaulz/videos/vb.100002393382787/964803770276060/?type=3
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All opinions aside, the OP posted June 19th and has had the bike soaking for maybe a few days. The OP has stated - is not in a rush.
With all the cautionary statements I have read about the doom and gloom with freeing up and riding the bike, I have only read one post where there was oil consumption and puffing a little smoke yet still useable. The soaking and attempting to free is ultimately moving in the necessary direction whether to ride and see how it behaves or to dismantle and rebuild.
I say take it a step at a time unless you have some hard deadline; there's really nothing to get too excited about as there are multitudes of outcomes here. The soaking is not causing any harm. I would use caution when using heat around the barrels, especially with open flame seeing how there is acetone, oil and maybe some gasoline lurking abouts.
One thought I have about fluids in the bores is if there were any water, it is probably down to the bottom beneath the oil and acetone. Acetone is miscible in water so this may be good. You may want to syringe out the stuff you have in there and freshen up the soaking/penetrating concoction a bit to remove some of the water (assuming there is water in there). Also take note if the fluid you remove looks rusty or has bits of rust in it, absence of same does not mean much, just a little bit more evidence. To really clean out the combustion chambers you might consider compressed air with a little copper tube stuffed down in the combustion chamber to blow it out but I strongly caution here that the mist coming out will be flammable and if you get it right, explosive.
Next time you look in the combustion chambers, see if you can see or probe for where the piston is. Close to Top Dead Center (TDC) is a good thing for protecting most of the bore and mechanical advantage to break it loose.
If you are ambitious and can determine if you have a cylinder with both valves closed, have somebody rig up or cannibalize an old sparkplug so that you can put some compressed air through it. Snug the plug in the sparkplug hole and add compressed air. I am figuring that 110 psig is good for about 800 lbs force on the piston.
jzmax22 - I seem to recall you did a change of fluids. If you have not done so already, you will need to remove and drain the oil in the sump of the engine. Although the Norton twin is by design, a dry sump engine, it does wet sump where after sitting for an extended period of time (yeah, 7+2 years is extended) it will have wet sumped. When draining the oil, also look for clues like water or large bits of broken stuff. Who knows, maybe it was blown up and put away.
Where are you located?
With all the cautionary statements I have read about the doom and gloom with freeing up and riding the bike, I have only read one post where there was oil consumption and puffing a little smoke yet still useable. The soaking and attempting to free is ultimately moving in the necessary direction whether to ride and see how it behaves or to dismantle and rebuild.
I say take it a step at a time unless you have some hard deadline; there's really nothing to get too excited about as there are multitudes of outcomes here. The soaking is not causing any harm. I would use caution when using heat around the barrels, especially with open flame seeing how there is acetone, oil and maybe some gasoline lurking abouts.
One thought I have about fluids in the bores is if there were any water, it is probably down to the bottom beneath the oil and acetone. Acetone is miscible in water so this may be good. You may want to syringe out the stuff you have in there and freshen up the soaking/penetrating concoction a bit to remove some of the water (assuming there is water in there). Also take note if the fluid you remove looks rusty or has bits of rust in it, absence of same does not mean much, just a little bit more evidence. To really clean out the combustion chambers you might consider compressed air with a little copper tube stuffed down in the combustion chamber to blow it out but I strongly caution here that the mist coming out will be flammable and if you get it right, explosive.
Next time you look in the combustion chambers, see if you can see or probe for where the piston is. Close to Top Dead Center (TDC) is a good thing for protecting most of the bore and mechanical advantage to break it loose.
If you are ambitious and can determine if you have a cylinder with both valves closed, have somebody rig up or cannibalize an old sparkplug so that you can put some compressed air through it. Snug the plug in the sparkplug hole and add compressed air. I am figuring that 110 psig is good for about 800 lbs force on the piston.
jzmax22 - I seem to recall you did a change of fluids. If you have not done so already, you will need to remove and drain the oil in the sump of the engine. Although the Norton twin is by design, a dry sump engine, it does wet sump where after sitting for an extended period of time (yeah, 7+2 years is extended) it will have wet sumped. When draining the oil, also look for clues like water or large bits of broken stuff. Who knows, maybe it was blown up and put away.
Where are you located?
Dances with Shrapnel said:
Thank you, no rush here.
I plan on pumping the fluids out to start fresh.
I've read a bit up on using compressed air, sounds like a decent idea to try anyways. Really no rush here, it's my summer project at night b while the kids are sleeping.
The bike when it was parked ran great, my father just got a little too old to Kickstart it anymore, so it sat. Outside, covered, but outside, through 2 tough Winters and then garaged , unheated for another 7.
He had new seals, new (old) amal carbs, new isolastic shocks all around, sold state ignition, new petcocks, new headlight, seat, foot rubbers and brakes.
I know most of that means nothing now, but it's not old stuff that sat. So it's definitely seized from rust.
I stuck a wooden dowels in the plug holes to gauge the distance to the top of the Piston, roughly 8-10 inches. An old timer also told me he used to use a wooden dowel down the plug hope to tap on the Pistons gently to try to free it up as well. Haven't tried yet, but it sounds like a very decent idea. If that helps determine what position the Pistons are in.
I'm located in upstate NY,US
[quote="jzmax22
I know most of that means nothing now, but it's not old stuff that sat. So it's definitely seized from rust.
I stuck a wooden dowels in the plug holes to gauge the distance to the top of the Piston, roughly 8-10 inches. An old timer also told me he used to use a wooden dowel down the plug hope to tap on the Pistons gently to try to free it up as well. Haven't tried yet, but it sounds like a very decent idea. If that helps determine what position the Pistons are in.
I'm located in upstate NY,US[/quote]
Rust is what I believe most of us all figured, and not just a light case of it either. I don't get 8-10 inches to the piston tops though. The stroke is only 3 1/2 inches. adding the distance to the top of the plug hole you only get around 5 1/2 inches, tops. That mystery aside, it sound like the pistons are at bottom dead center, meaning they ain't going down any further so tapping them with anything will do nothing. They'll have to come UP someway.
I know most of that means nothing now, but it's not old stuff that sat. So it's definitely seized from rust.
I stuck a wooden dowels in the plug holes to gauge the distance to the top of the Piston, roughly 8-10 inches. An old timer also told me he used to use a wooden dowel down the plug hope to tap on the Pistons gently to try to free it up as well. Haven't tried yet, but it sounds like a very decent idea. If that helps determine what position the Pistons are in.
I'm located in upstate NY,US[/quote]
Rust is what I believe most of us all figured, and not just a light case of it either. I don't get 8-10 inches to the piston tops though. The stroke is only 3 1/2 inches. adding the distance to the top of the plug hole you only get around 5 1/2 inches, tops. That mystery aside, it sound like the pistons are at bottom dead center, meaning they ain't going down any further so tapping them with anything will do nothing. They'll have to come UP someway.
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Agree with the near BDC assessment. Good thing is you will have a decent mechanical advantage near BDC to break it loose. You will also be closer to getting your pistons out of their bores if/when it comes to that. The bad thing is that it sounds like much of your bores were exposed.
Rock it and wait and repeat. If/when the pistons break loose, if you cannot relatively easily work the engine through a few rotations, time to piss on the dogs and call in the fire - pull the head and barrel.
Without really knowing the cylinder wall conditions, we don't know exactly the magnitude of what we are dealing with. Engines have been locked due to localized minor corrosion of the rings to the walls with little to no rust on the cylinder walls. The worst I have seen was when doing a rebuild on a two seat early 60's Mercedes Benz where the gal worked in a US school overseas and left here car on the blocks in the garage for a few years. The anti freeze ate through the head gasket into the combustion chambers and froze (swelled) the alloy pistons into the bores. Judicious use of hammer blows and a hard wooden block were necessary to break it loose to dismantling.
Rock it and wait and repeat. If/when the pistons break loose, if you cannot relatively easily work the engine through a few rotations, time to piss on the dogs and call in the fire - pull the head and barrel.
Without really knowing the cylinder wall conditions, we don't know exactly the magnitude of what we are dealing with. Engines have been locked due to localized minor corrosion of the rings to the walls with little to no rust on the cylinder walls. The worst I have seen was when doing a rebuild on a two seat early 60's Mercedes Benz where the gal worked in a US school overseas and left here car on the blocks in the garage for a few years. The anti freeze ate through the head gasket into the combustion chambers and froze (swelled) the alloy pistons into the bores. Judicious use of hammer blows and a hard wooden block were necessary to break it loose to dismantling.
concours
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$56 with a soupercoup... https://www.harborfreight.com/digital-i ... 62359.html
Amazingly good images, at a ridiculously low price.
Amazingly good images, at a ridiculously low price.
Dances with Shrapnel said:
I don't know about that my friend. Half way down or up will give the best leverage/torque advantage of breaking the rings/pistons free. @ jzmax22 I know you're impatient and I don't care what others say here, but once you get the pistons free, and you will eventually, concentrate on boring the barrels, new pistons and rings and refurbishing the head, not just "gettin' 'er goin' ". Honestly, just think about it, where do you suppose the rust that's been "welding" the pistons, rings, and cylinders into one happy family all these years is going? It's getting washed up and down a bunch of times, scouring the bores and getting washed into the bottom end where it will attack the main bearings, big ends wrist pins, cam, and followers. The valve stems and guides will be impacted too. The bores will be semi cleaned of loose rust and except for the pits left, will look polished. It will be polished rust though, not the best finish for oil control or compression, but then again neither will the pitted from rust rings, or the cratered valve faces and seats.
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Thanks concours. I was about to chime in on that bit.
As for the hellfire and brimstone predictions that Biscuit is expounding on here; just can't get too excited about theses things, especially if you don't know. Really the first step is breaking it loose anyway so let it soak and jiggle the wheel now and then.
Nothing wrong with deliberate speed on this one. If it breaks free and turns through rather easily, hell , why not have a go at it. Run it and change the oil once or twice and enjoy. Somebody was already talking about new pistons and rebore so if it smokes and consumes too much oil then new pistons and a rebore. After all, where are all the Norton motors that were rusted/frozen, freed up and did smoke to high heaven? Maybe with some more information like a bore scope or trained eye looking at the cylinder wall would take this in another direction but until then, let it soak and let modern chemistry do the heavy lifting here. If it breaks or budges a bit but does not really want to move then sure, time to take off the head and barrel, especially since you have the piston freed - right?
As for the hellfire and brimstone predictions that Biscuit is expounding on here; just can't get too excited about theses things, especially if you don't know. Really the first step is breaking it loose anyway so let it soak and jiggle the wheel now and then.
Nothing wrong with deliberate speed on this one. If it breaks free and turns through rather easily, hell , why not have a go at it. Run it and change the oil once or twice and enjoy. Somebody was already talking about new pistons and rebore so if it smokes and consumes too much oil then new pistons and a rebore. After all, where are all the Norton motors that were rusted/frozen, freed up and did smoke to high heaven? Maybe with some more information like a bore scope or trained eye looking at the cylinder wall would take this in another direction but until then, let it soak and let modern chemistry do the heavy lifting here. If it breaks or budges a bit but does not really want to move then sure, time to take off the head and barrel, especially since you have the piston freed - right?
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