20 Most Recent 1980 Yamaha XS 400 Special Questions & Answers

I have a a 1978 xs1100 and i have used almost any motorcycle brand 10W40. Has worked well in all my bikes From a 250 cc to 1400 cc.

You will need to remove the alternator rotor(LH side of the engine) which requires a special tool. You can attempt to bribe your local Yamaha service centre mechanic but I doubt you'll have much luck. Using a gear puller is not recommended as it could damage the rotor. The correct tool screws into the middle of the rotor to seperate it from the crankshaft.

Is this while the bike is running? If not, start it and see if they flash then. The old thermal flasher relays require more power to operate than newer electrical relays and won't function with just the battery, usually. If they still don't flash with the bike running, replace the flasher relay. Any automotive store will have something that should work, you don't have to go with an OEM part here. If you're feeling ambitious, you might replace the flasher bulbs with LEDs (I get mine from superbrightleds.com) and go with an electric (or electronic, I forget how they designate them) flasher unit. Less draw on your charging system and brighter.

YAMA LUBE 10W 40 and it should hold about 3 qaurts

probly lo on fluid--get a repair manual soon

Hi Lily,

Here is a link to some useful info about the carbs...
http://www.yamahaclub.com/forums/index.php?showtopic=14526

You can get the manual here, where you will need to register then login, before you can download it.
http://www.repairmanualclub.com/motomanuals/index.php?dlid=993
If you have any more questions feel free to email me. [email protected]

and please rate me if helped you.
Thanks and good luck.

Try pulling the carbs, and then the jets. Give the jets a good cleaning, should be fine after. Also, run stay bill in your gas for no future problems.

Hello,

It sounds, in my opinion, that you have a break in your wiring or a loose connection (could be a missed blown fuse) - you could also have overloaded the fuse panel (look for burned areas on the front and back of the fuse panel). I use a live circuit tester, turn the ignition switch on, and run the tester over the wires - of course this would mean that there would be power to the ignition switch.

Did you upgrade to a higher wattage, or halogen, headlight? Did you go to a Three Light System? If so, you may need to use a load stabilizer or equalizer to maintain the correct current throughout your electric wiring system.

Another thing to look for is a secondary fuse, could be in-line, to your ignition.

All of the above is just to help you with a starting position. Electrical problems are very difficult to diagnose and time consuming.

Take your time and if you find yourself getting frustrated, take a break for a bit. Remember to jot down the fuses and wires you have checked - this will save confusion later.

Hope this helps you out.

Regards,

Oz

Get yourself a a oil pan trey to drip the old oil in. If you lay at the bottom of the bike you would see a big nut at the bottom should be a 17 or 15 inch, before unsrewing the nut (anti-clockwise) lay some newss paper under the bike and keep your oil trey near, position the oil trey below the nut just before you turn it completely loose best to undo it at the end by hand,
wait until all the oil has dripped out would advice replaceing the o ring inside the bolt you just removed.
once all the oil out you can put the srew back in
oil filter is just behind the manifold should be a 14 inch nut just loosen and remove the whole unit wil come out pull off the oil filter from the unit and replace with new one also replace any worn o rings and put back in then you may fill up with new oil .
Strongly advise buying you some good oil it's better to spend the extra money on oil that would prolong your engine and keep it running smooth

good luck

I've just been looking over my manual on this bike and it might be worth your while taking them off and having someone else service them, and you put them back on.Carbs are not what I would call a fun job,but if you're into it get yourself a manual,a clean place to work,lots of patience,and be prepared to spend four to six hours cleaning them up.I just did a set of four carbs on a Yamaha XS 1100,and I had to clean them three times before I got all the grot out.I'm not trying to scare you ,just letting you know what you might be in for! Make lots of diagrams,take lots of digital pictures,and I think once you have done a set or two I think anyone who is handy will catch on.Patience is everthing,best of luck.

You have a loose plug in connection or a broken wire (wire broken inside plastic tubing) . These would cause the light to flicker when driving over bumps in the road. An old headlight bulb might also flicker if the filament is starting to break loose. One last possibility would be a dirty switch on the handlebar ( arcing through a burnt contact). You could try taking the switch apart and clean it. Unplug and replug all connections checking for loose or corroded ends/plugs where the wires are soldered in. Pull and bend/twist sections of the harness hoping to find a bad spot you can bypass and remedy the problem.

It sounds like you have a carburetor float that is stuck in the down position flooding the cylinder with gas. Start by removing the carburetors and giving them a thorough cleaning . Closely inspect the sides and tips of the float needles.If they show wear or damage replace them. If you have black plastic floats , test that they float in a cup of gas and do not sink . If the float sinks replace it. Ethanol fuel will saturate black plastic floats over time causing them to sink. Change your plug , it is probably wet fouled from the gas and check the new plug for spark. Also check that your crankcase has not filled with gas during the flooding. That is why you should always turn your gas off when not riding so if a float sticks you do not ruin your oil. If gas has fouled your oil, change your oil.

The gap should be .015 with the points arm on the high point of the cam. There is a chance the new condensor could be bad from the factory. Not very likely, but remounting the old condensor would eliminate that as the problem. Is there any chance the wires are disconnected or broken anywhere? Use a multi meter to check for power at the points. Have you checked the fuse box? Is the Kill switch on? Check the side stand kill switch also if your bike has one. Good battery? Install new spark plugs. Carbon buildup on the plugs can rob electricity needed for a spark. Please rate my answer. Thanks.

First, you need a good battery. The bike does have electronic ignition. Soak the carbs in denatured alcohol for two hours after removing the float bowls, then clean with spray cleaner. Spray into every large and small hole you can find. Remove the rubber diaphragm from the center of carb prior to cleaning. New diaphragms are $196 each. Check all fuses. Put in new spark plugs, NGK-BP7ES. Clean the air filter. Get a can of spray starter fluid and spray on the air filter. The rubber mounts for the carbs are likely to be a problem once it gets running. It looks like they are still available at Babbitt's, $53 each. If un-carburetored air can get into the joints it will lean the fuel mix and cause uncontrollable high idle.

Before you sink a lot of money into the bike, check for spark. If spark is present, coast the bike down a good sized hill without any spark plugs being installed. Put the bike in 3rd gear as you go downhill then let the clutch out to turn the engine over. Now ( using the clutch lever ), shift through all the gears then neutral. If the bike will not shift properly it likely has a bent shift fork. I can't find any forks avaiable. With a bad tranny I would put it back in the dirt floor building and find a newer bike. Here is a link to Babbitt's. Please rate my answer. Thanks.
www.babbittsonline.com/pages/parts/viewbybrand/default.aspx