1979 xs1100s ignition issue

[dondons1984]

Tank is shiney the guy took care of the bike and drained and maintained

[BA80]

Plugs are cheap and easy. It won't hurt.

Spark plugs do break down inside over time.

Have you checked you pick up coils?

Why did the PO park it?

[dondons1984]

I've gotten. It to fire a couple times and I took the likes off also to clean and tried to turn it over and it is obvious I got fire cause I got fire out of them. Unless the pickup coils are something else?

[mikubuilder]

Welcome Dondon , for $250 it's a steal

since you have tank of, you can do a few quick checks with multimeter to see if your electrical system is up to par

first make sure your battery has over 12V
second when you turn the key to ON you have still 12V after first two fuses (looking from left to right)

third check resistance of your coils, primary and secondary

if that checks good, you can see if your red/white wire to coils is getting 12V, with a key ON

it might be helpful, to go through entire system and clean up ALL ground connections, including one under the reg,/rect. or even go extra mile and add a ground shunt from battery straight under the reg./rect.

just my 2 cents

[BA80]

I've gotten. It to fire a couple times and I took the likes off also to clean and tried to turn it over and it is obvious I got fire cause I got fire out of them. Unless the pickup coils are something else?

Don't know what the "likes" are but put some fresh plugs in it and see how it acts.

Pick up coils are under the left front engine cover. Sends the signal to the TCI to fire the coils. But if you have fire to all 4 plugs that's not going to be the problem.

[TopCatGr58]

Hey Greg,

I think he meant to say he took the lines off, the fuel lines to clean them.

Don, you got spark and you got it to try to start when you had fuel poured into the plug holes/cylinders directly. The XS11 ignition system used a wasted spark system,m so 1-4 plugs fire at the same time, and 2-3 will fire at the same time. So...if you had some fuel in the cylinder that was on the exhaust stroke when the spark fired, it would make a backfire.

You have allegedly professionally cleaned carbs, spark, but no run! Will run with added fuel to cylinders, but not with just the carbs. Sounds like either a fuel supply problem, or fuel delivery problem of the carbs themselves...could be from a vacuum leak. Need to check the intake boots and synch port caps as sources for the leak.

You also have a leaky petcock. But as long as fuel is flowing thru it to the carbs it shouldn't keep the bike from running. You have an SF(Special), do you still have the fuel control Octopus device?? Are you using the choke/enrichener when trying to start it? Do you have the fuel lines plumbed correctly?? There's a jet in the bottom of the float bowl, may have been missed, if clogged, choke/enrichener won't work.

T.C.

[dondons1984]

Carbs were rebuilt by Yamaha. I have all the paperwork for it.

[BA80]

Carbs were rebuilt by Yamaha. I have all the paperwork for it.

When?............

[dondons1984]

Carbs were rebuilt a little under 2 months ago according to the Yamaha receipt. I decided to check them yesterday and they look fine. Nothing wrong with them. Drained them yesterday also and fuel came out of all 4. I will be changing the plugs later today after work cause I found from the po that they haven't been changed in 15 years so I'm hoping that can be the issue. I am also going to check all the electrical with my multimeter and see if all is good there. Yamah bikes are pretty new to me since I used to own a gl1100. Thanks for the help guys. Also I will be needed the petcock re build after all since I started leaking bad yesterday. I was thinking of just converting to just one petcock but I'm worried there is a reason yamaha had 2 in the first place.

[BA80]

It will work with just 1 petcock but you'll loose the use of the fuel that gets trapped in the opposite side of the tank.

[dondons1984]

How much do you think I lose? And it won't affect anything else will it? Does anyone here run off one petcock? I'm curious how someone seals it if you use a steel plate and weld it or if you can use jb weld and a steel plate? Cause if I am only losing say half a gallon then I'll do the change.

[BA80]

If your bike still has an octy you can run off of one petcock and answer your own question.

The octy acts as a t between the 2.

[dondons1984]

OK well I think I'm just going to do that then. I'll keep everyone posted. I'm cleaning up the bike bit by bit and find that I enjoy it beyond belief. I just slam my head against a table when I get stumped on the engine firing cause it should be simple as gas compression and spark. I have gas I have compression so it has to be spark.

[BA80]

How are you coming along with getting it running?

[dondons1984]

It tries to turn over every time. I thought maybe it was my carbs so I looked through the records and found they were rebuilt. I checked and they are good. Took off exhaust to make sure it was all clear and it is. Took plugs off and checked compression and that's good. So rather than not fully turning over it truly is so nice bike and getting closer and closer to riding