Can regular fuel hose be used to replace worn rubber hoses at fuel tees on carbs 1&2and3&4

there should be two inlet connections -- one for hot water (red) and one for cold (blue)
there should be two hoses with the ends color coded
inside of the fitting the screws onto the back of the machine there should be a rubber washer
that is what seals the hose onto the machine fitting
-- same rubber washer that is in any 1/2 " hose to tap fitting

Yes it sounds like it is. Threads are worn or damaged. Also make sure you have a rubber seal in the end of the hose to stop the leak. Get a new inlet valve fitted.

You can us the regular fuel hose.

Turn off fuel tank petcock valve. Remove complete air filter assembly. Disconnect fuel hose from bottom of petcock(may have to cut hose clamp off and will have to replace with a regular worm screw hose clamp). Hold a rag around the end of the hose where you are pulling it off to catch and squirted fuel. You then pull hose off the carbs elbow fitting the same way you did at the other end. If hose on carb is not easy to access, you may have to pull the carb out of the rubber boot that connects the carb into the intake manifold. Replace hose with same length of new hose which is 1/4" fuel line hose. Reassemble in reverse order using the above mentioned worm screw hose clamps.

write note on where the air screws are adjusted before pulling them out.
If you see something you may confuse later take a photo, like vacumn hoses, overflow hoses, fuel hose.
The slides may look a little worn, this is usually not a problem, apart for obvious cracks, then its replace all four
dont touch the adjustable syncronizing screws, that lift all the slides together.
dont mix parts between carbs.
When putting them back on
Check the inlet rubbers and install them tight
Make certain the throttle snaps all the way back before starting the bike.
And of course work in a clean area, and remember its fuel and will burn when it can, so no ignition sources.

Thermostat Removal & Installation To Remove:
Thermostat

1. Drain the engine coolant.
2. Remove the air cleaner.
3. When disconnecting the radiator lower hose connection, put mating marks on the radiator lower hose and hose clamp before you disconnect them.
4. Remove the water inlet fitting.
5. Remove the thermostat.

To Install:
Thermostat

1. Install the thermostat so the jiggle valve is facing straight up. Make sure not to fold or scratch the rubber ring. CAUTION
   Be certain that no oil gets onto the rubber ring of the thermostat. Also be cautious not to scratch or fold the rubber ring as you install it.
   
2. Install the water inlet fitting.
3. When connecting the radiator lower hose connection, do the following:
   • Step 1: Insert each hose as far as the projection on the water inlet fitting will go.
   • Step 2: Line up the mating marks on the radiator hose and hose clamp, then connect the radiator hose.

I assume you mean on the fuel assembly? Any fuel hose would work if you're talking about the rubber one. They go bad now and then and we just take a regular fuel hose, cut to length, and replace it. Works for years. As for the metal pipe, same thing. Although, you might want to cut it out and replace with rubber hose. Finding a pipe is a pain so we use hose and hose clamps.

I've done it using the appropriate size piece of copper pipe stuck in the hose and use clamps on either side.

find the offending carb or carbs by pulling float bowl over flow hoses to the side and starting motor, 1 or move hose will be pouring fuel, follow hose to offending carb, unmount all 4 carbs from motor,(unmount tank,1 bolt 2 hoses,2 wires) then (unscew hose clamps from front and back of carbs) next(reomove scew from very top font of air box,near metal cross bar behind fuel tank) then wiggle carbs to separate from rubber intakes,unhook trhottle cables pull carbs out one side(either side of bike) once off turn upside down,take 4 bowl screws out ,remove cover,take out small pin holding floats ,needle will come with it,use the right wrench and uscrew brass seat needle came out of(make sure any rubber o ring come with) reinstall seat &any orings take old needle off float install new one,put needle in hole of seat,pin float put cover back on bottom of carb,re assemble bike.I hope you've maked where everything goes,a little oilon rubber helps with reassembly .













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It's not really a solution-it seems there are two sizes OD (.700", .620") both called 1/2" tubing. The appropriate sized fittings must therefore be used