New 74 xs owner and rider.

[Howlinwolfxs]

i have to de rust the tank. so its now empty, and im trying to decide which direction to go on the rust.

Pretty sure my front master is going to need rebuild. how do i identify it?

 

[mrtwowheel]

Rusty tank, I've tried all of the methods on tanks and the easiest, cheapest and best working way to do this is electrolysis for me. All you need is a DC power source (battery and automatic charger, or, non-automatic battery charger, or, large DC transformer like an old video cam charger) a piece of scrap metal and a box of Arm & Hammer Super Washing Soda available at Walmart or the dollar store. Once your tank is clean there is no good reason to seal it with epoxy that may deteriorate and be nearly impossible to remedy later.

Master cylinder, if the rubber parts look good without holes don't disassemble it. I believe that 98% of the time they don't work because of hardened up fluid and plugged holes. Clean it well with "brake cleaner" and make sure that the two small, tiny, holes inside the reservoir are clear and not clogged. All that goes wrong with these is the rubber parts and not really very often. clean it, don't disassemble it. Save your money for paint and something else.

Scott


So many things can be fixed properly without throwing new parts and money at them.

 

[Howlinwolfxs]

so the best idea is to pull the line, and make sure brake kleen comes all the way through? (trust me im game for the easy way) but i figured a rebuild kit was better than another MC. I also didnt plan on doing any coatings, as i have had bad luck on a four wheeler i had. I figured if there are pinhole leaks, ill pay someone to fix it.]



also, i think my right carb has a stuck float

 

[XSLeo]

They called it a TX for two years and lumped it in with the TX750 and TX500. Both well known by the speed they flopped. In 75 they went back to the XS designation to distance it from the mistake they made with the TX500 and 750.
Leo

 

[mrtwowheel]

Don't spill "brake fluid" on anything, it eats paint. Cover things with plastic and have water ready in case you spill fluid, a spray bottle will even work.

Painting parts is part of the fun.

Yeah, take the hose and clamp off, dump the fluid and spray it, scrub it, poke it and use air to clean it.

Scott

 

[Howlinwolfxs]

sigh. The right side carb wasnt flowing fuel, I pulled it, dropped the bowl, it had fuel in it, i blew through all the tubes, everything seems clear, also the diaphram seems ok. i covered the hole and the slide comes down slow. i put it back on, and no go. it will sputter, but wont run.

 

[1974jh5]

That's better than what I started with. Mine was in pieces, there was a bunch of stuff in a huge plastic flowerpot.

 

[Howlinwolfxs]

I wont buy things in pieces anymore. i tied up so much time in beretta gtz that was in pieces. i got it on the road, and loved it, but i would rather disassemble my own projects.

 

[1974jh5]

I know what you mean. The best thing about my disassembled XS650 project (and the disasembled Hodaka Super Rat before that) was they were free.

 

[Howlinwolfxs]

I just want this thing to run before i do other stuff. I know i would be pretty stressed out if i pulled the whole thing apart and put it together, and it didnt run...

 

[Howlinwolfxs]

if the tube that seems to run between the choke is split, could that cause it not to run?

 

[1974jh5]

90% of carburetor problems are ignition problems. Before fiddling any more with the carbs, be sure the ignition is in good working order. A '74 should have points and condenser ignition.

Points are VERY finicky about being clean. It's worth the time to file and clean the points thoroughly and regap. Somewhere on this site is a link to a PDF of the original service manual which outlines that procedure. A good way to clean them after filing and regapping is to stick a piece of paper between the contacts and then pull it out, you will probably see a gray or black streak on the paper. Do this a couple of times.

Easy way to check/set the ignition timing on points without a timing light: use a piece of cigarette pack cellophane, turn the engine till the points open, then slide the cellophane between the points. Turn the engine till the points close on the cellophane. Now pull gently on the cellophane and turn the crank with a wrench. The point where the points let go of the cellophane is the time at which they open and the coil fires when the points open, not when they close.

Also, a bad condenser will drive you nuts because you will have spark at the plug but the damn thing won't run (remarked the voice of experience ). Car condensers are cheap, like $3 apiece, and will work fine on a bike. You should have one on each coil. In fact, make sure they are plugged in, you never know what a DPO (Dreaded Previous Owner) disconnected, etc.

This sounds difficult but it's not. Should take maybe an hour or so. Once the ignition is known to be in good working order, then you can evaluate the carbs.

 

[Howlinwolfxs]

p.o. was my dad. he parked it because it was hard to start, and the clutch was slipping.

I had it running, but it was only on one cylinder. With a hit of carb cleaner, the other cylinder woke up and fired, if only for a moment. I pulled the right side carb and made sure all the lines were clear, and now it wont fire at all.

 

[mrtwowheel]

Carb cleaner is destructive to the plastic and rubber parts of your carbs. Brake cleaner and Lysol and some others are known to be safer for your parts.

Scott

 

[Howlinwolfxs]

ok. thanks for sharing that! but, that tube, between the carbs on the choke, or what i think is the choke, the tube is split, would that cause a no start condition?

 

[nj1639]

Got any pics of what you're talking about, might help.

 

[Howlinwolfxs]

not at the moment, but there are two lines that run between the carbs, one is a fuel line, and the other runs near the choke bit of the carb.

 

[1974jh5]

If it has a crack, try shooting a small amount of carb cleaner at the crack with the engine running. If the engine changes speed either way then there's a leak there that needs to be fixed.

If it doesn't change anything when you spray at the tube, try this: take the air cleaner hoses off, if they aren't already, then start the engine. Slide your fingers over the intake 'bell' of the dead cylinder, being careful not to close off the vacuum port for the slide at the top. If it starts running a lot better as you close it off, then you may only need to use the balance screw between the carbs to open the throttle flap on that side.

 

[Howlinwolfxs]

it wont run at all now, but ill see if i cant do something

 

[weekendrider]

The choke line feeds the right carb so, if split your probably sucikng air not fuel.
Plain ol vinegar is a good way to derust tanks. Cheap and enviromentally friendly.
It is amazing how little crap it takes to stop up the carb jets.