850 Commando sitting for 9 yrs

concours said:

Welcome.

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DennisMo said:

I would suggest to put a bit of oil into each cylinder and kick the engine over a few times
with ignition off and spark plugs not in and then let it sit for a few days to let the oil run down to the piston rings...

As for quantity of oil, perhaps 20 mls. You don't want to put in so much that you get hydraulic lock when
you crank it with spark plugs in.

Make sure it has a decent fuel filter as there may be some particles coming down from the tank.

I suggest to flush the brake fluid and put in new fluid

If you do try start it with the points still in, don't touch them other to get a small file between them and clean them as there might be a film of corrosion on them meaning no spark. It would be an idea to check for spark before you really try to start it by kicking it over with fresh battery and plugs out, no fuel in tank and each plug with high tension lead attached, and each plug touching ground. My suggestion would be to get it running on the points before you install Boyer or similar. Too many variables.

Also an idea to see that the clutch driven plates are free when clutch is pulled. Thus ignition off, bike in gear, pull in clutch and see if bike will roll when pushed.

Dennis.
Bought my 1973 about a year ago

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Onder said:

The more you do BEFORE you start it the less you will have to repair after you do. To do it 'right' you have to do a lot
but it will have a big return in the long run.
Take the petrol tank off and slosh it out several times. If you have rust in there, deal with it now not later. Phosphoric acid
works but mask the exterior paint well.
If it sat, all the fines will settle and stick to the surfaces of the timing cover, primary and crankcase interior. Take them off and clean. Do the big sump plug filter bit. You will have to go into the timing cover anyway to check the little chain. Might not hurt to put in a new oil pump seal too.
Need I mention the layshaft ball bearing?
Great thing about Commandos is that almost everything is available new.

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Saber said:

Theres a lot of experienced owners around. What part of the country are you located in?

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johnm said:

A 1974 850 with so few miles in original shape is a brilliant find. Many consider it the best model.

But realistically if you want to use a bike of that age which has sat around alot yiou will need to do a fair bit of service type work.

First off the tyres and tubes are probably history.

Starting with the suspension. Drain and replace the front fork flyids. If you get rusty water out of them you may need to dismantle them but otherwise renew the oil.

The rear shocks may have no dampening left. Depending on type you may be able to get them serviced.

Tank has to come off and be flushed as described above. While it's off check over the wiring for cracked or damaged insulation. There should be a 5 wire connector under the tank which is famous for basically falling to bits with age. If your good with wiring I'd go through the lot with a multimeter checking for poor connections. Especially the main switch, the handle bar switches and the kill button if connected. My bike sat in good conditions for 5 years and I found about 4 bad connections from memory. The new battery is a good recommendation. You have options on the ignition and I'd go with whatever you feel OK with. I use Pazon but that's as much that Andy lives in NZ and responds in a few hours whenever we have issues. ( ignitions used on race bikes) . New plugs probably and maybe new HT leads.

Drain all the fluids including primary. New oil filter and I'd probably wash out the oil tank too. It will give you a heads up if there is any motor issues. Check the oil pipes carefully. After this time they may be cracked or perished. Personally I'd probably instal new ones.

Oil down the barrels is probably a good idea. BUT DO NOT TURN THE ENGINE OVER UNTIL YOU HAVE REMOVED THE TAPPET COVERS AND POURED SOME OIL DOWN THE PUSHROD TUNNELS TO LUBE THE CAMS AND FOLLOWERS. While your in there check the tappet clearance.

The suggestion about replacing the layshaft bearing is a good one. This is a necessary upgrade and a safety issue.

I'd also pull the clutch and clean it because it's probably stuck together by now. This also gives you a chance to check the wires from the stator through the hole at the back of the primary case. They often wear and break at that point.

Carbs. Definitely totally clean. Ultrasonic bath if possible. The mixing chamber under the pressed in brass plug is almost certainly blocked. Someone recomended the Bushman's notes I think. Good suggestion.

Brakes. I'd replace the seals in the calliper and master cylinder. The linings on the rear shoes can delaminate if left for years. I know. It happened to me so new brake linings or shoes may be in order.

Whatelse. Obviously go over the bike with and oil rag and check for corrosion, lube all the cables and levers. The isolastics will probably need adjusting. And the chains. Swinging arm will need oil. 140 wt.

OK. So that's off the top of my head based on a referb I did on my 850 after some years in storage.

There lots of good ideas above as well.

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trappnman said:

My suggestion would be to get it running on the points before you install Boyer or similar. Too many variables.

I would have to respectfully disagree. I understand your point, but the biggest variable IS the point system. Getting both sets of points timed exact, is an art (and I've got over 50 years of running nothing but points in my bikes until a few years ago with the cheap parts out there went to EI for everything. I hesitated too long went I got the Combat back on the road after sitting 20 years and messed with the point systems, even replacing everything until it was enough is enough) and went with the Pazon. A breeze to install, and it immediately eliminated that variable in getting everything tuned and running right.

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YING said:

Hammer,
You have acquired a good motorcycle to start with!All of the suggestions that have been posted will make your life easier and your main expense will be some special tools which are readily available and some fluids.Mainly labor and get a factory manual.In the end you will be a happy camper!
Mike

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Hammerswinger said:

that would have been my inclination as well, no disrespect to DennisMo...

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johnm said:

"There was a comment about putting some oil in the cylinders, but I didn't note if anybody suggested some oil on rockers and valve stems. It can't hurt."

And down the push rod tunnels.

I can't have made my capital letters big enough.

This is an absolute necessity before turning the engine after years in storage. Or one swipe and you can destroy the face of the followers and cam lobes.

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Alan L said:

This will sound like heresy too some, insanity to others and perhaps just incorrect by most but I would simply refresh all fluids, kick over a few times with the plugs out and a few drops of oil then start it. If it was put away in good condition it will probably be fine, stale petrol and varnish being your biggest problem.
There is no end of thing you could do but why? It will run or it won’t.
Regards
Alan

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