20 Most Recent 1979 Yamaha XS 650 SF Questions & Answers

should be behind one of your sidecovers, good luck to you friend...tim

use plenty of penetrating oil normally a exhaust shop would apply a lot of heat to the join as that breaks down the carbon/rust and allows it to tap apart

I found that with mine. It would start and run for 10/15 seconds and stop. Leave a couple of minutes and start no problem then stop again. Took whole ignition system to Boyer Bransden and they tested it and the brain box was faulty. Replaced that and bingo. SORTED. Over 40 Years Proven Performance

I"m not 100% sure what will or will not fit your bike. One thing I usually do is go to babbittsonline.com and look up your part numbers for your main shaft, counter shaft, bearings, gears, seals, everything basically. Then (and this is a little time consuming but will save you a lot of trouble getting what you need) one by one, you can copy the part numbers and back-page until you get to the screen where you can search individual part #'s. Enter the part # by pasting it in and when it comes up with the description just click the "where used?" button and it will list all the years and models where that part is used.Time consuming? Yes! Effective? ABSOLUTELY!!!

HERE is a good article on tungsten and other filaments and their properties

the second gear is piting from rust[so the noise]the stuck is of the gear change ankor or damage spring

look in the manual get one here


http://www.repairmanualclub.com/motomanuals/index.php

SHUT OFF THE GAS PETCOCK, U HAVE IT IN THE "P" POSITION , P MEANS PRIME. IN THE MORNING START IT UP AND MOVE THE PETCOCK TO "ON" If you need further help, I’m available over the phone at https://www.6ya.com/expert/michael_00678fd4800d19c5

Take the bike to Yamaha for repairs

Sounds like you are missing a fuse panel. Don't forget the protection.

It's rust. You can try to use some penetrating oil on it, WD-40 is a close second. And if you were able to heat it up (running it) sometimes that helps, but you can end up burning yourself. The middle DOES come apart, and all you do is loosen that clamp and slide it out. No special procedure on this one. Rust will hold things in place very well. If you have to, find a way to grind the nut off the clamp, and buy a new one...but find one before you do this or you may wind up with more of a headache. The schematic I saw looks as though the exhaust will come off just after it bends to match the frame, so you can take both exhaust pipes off at that point and maybe slide it out from under the rear tire (if the bike is on its center stand?) Here's a link to BikeBandit, they have schematics for all the parts of your bike.

http://www.bikebandit.com/houseofmotorcycles/1979-yamaha-motorcycle-xs650-2f/o/m8268#sch215387

Hope it all goes well.

Bruno

Your original battery was a YUASA YB14L-A2 . Use that battery or an aftermarket equivalent.

It looks like Babbitts has them in stock. Go to www.babbittsonline.com/parts/viewbybrand/parts.aspx Please rate my answer.

There is no firing order. Your bike has a coil that fires on both the compression stroke and the exhaust stroke (also called a wasted spark). Therefore either plug wire can go on either cylinder and the bike should run the same.On four cylinder bikes this meant that you could run four plugs using only two coils and two sets of points instead of four coils and four points.If the bike is running poorly try new spark plugs and new spark plug caps first(start with the cheap stuff). Next check the actual coil and pulse pick up or points. You may have to replace the coil only because the wires are cracked shorting.

http://www.yamahaownershandbook.com.au/?r=0

Try this link from the Yammy Owner's Club, members have downloaded a whole pile of manuals for free download, just enter your bike model.
Cheers.

There is a resister in the spark plug caps that can cause a problem, try swapping the caps left to right and see if the miss changes side, the caps unscrew off the leads, if there is enough lenght cut 10mm off the end of the leads, when you screw the caps back on

pop the hood and its located on the drivers side little box about 6 inches wide says relay switches