Intermittant cutting off ...(new questions, pg. 3)

I have a build thread in the Other Bikes forum: http://xjbikes.com/Forums/viewtopic/t=4 ... art=0.html

I was told it's OK to ask tech questions here, so...

I bought the '87 Radian non-running, sitting for 9 months. Here's a quick run down of what the P.O. had to say about it:

-Ran great and ridden often until it developed a random "cutting off" issue. She said she would be tooling down the road and it would just die.
She thought it was a carb issue. Took it to a local shop and they "cleaned" the carbs, installed new genuine Yamaha manifolds, new Yamaha side stand switch. The problem still existed.

- I asked if it would sputter, bog, cough, stumble, etc. and she said "No, it was like someone hit the kill switch or turned off the key". That sounds like electrical to me.

-I asked if it would restart, and how quickly. She said "I'd sit there just long enough to get frustrated and then it would start. But I had to rev the piss out if it to take off."

I have the ignition switch off getting a key made. I'll check the ohms on it when I get it back.
I didn't see anything funky with the wiring when removing the switch, headlight, battery, signals, etc.

I charged the battery (just for testing...I'll get a new one once this thing is back on the road). It was pretty dry and I filled it and charged it and it is holding a charge. If the battery was weak, could that cause the ignition to fail intermittently like that? But then it shouldn't restart, right?

Could the CDI be heating up, "kicking out", then cooling down enough to let the bike restart? Or, when they die do they just...DIE?

Kill switch, maybe? How would I check it? I'll be swapping bars and I'll take a peek inside it when I do, maybe spray some electrical cleaner on it and make sure the contacts are clean.

What else should I check? Is this a known issue with this family of bikes? If I need a CDI, where can I get one without taking a stab in the dark on ebay? Even used ones aren't that cheap?

 

Re: Intermittant cutting off ...where to look first?

Symptons point to a failing ignition pick-up coil. They send signals to the TCI to fire the plugs. Cutting off when hot does point to something electronic, TCIs can also do that. Ignition coils don't fail in pairs.
Of course it could be something else, there are many things that can cause your problems. We just have to eliminate one at a time.
Has the factory fuse box been replaced? They are prone to failure.
Have a mulit-meter and spark plug ready and run the bike on the center stand until it stops. when it does pull a plug wire and install the spare plug and let it hang on the motor. Try to start it... is there spark? If not see if there is 12v on the TCI....If not find out why, if yes then test the pick-up coils.
Its a start could be something else.

 

Re: Intermittant cutting off ...where to look first?

When you say "pick up coils", do you mean the pick ups where traditional points would be? The pulsers? Or do you mean the actual coil that feeds the plugs wires/plugs?

I thought about coil failure, but as you said, they usually don't both go. If one had failed, she would have been running on 2 cylinders...rough, but running...and not just DEAD.

I have to finish the carbs (stupid shop....the #1 mixture screw and slow jet is really buggered up. Got everything else out, cleaned or soaking), and get the key back before I can even attempt to start it.

The factory fuse box is still there; I saw it when I moved the airbox to remove the carbs, but I haven't peeked inside yet.
I'm well aware of the Yamaha fuse box. I don't think I've had a single XS650 that had a good fuse box and the FJ600 has had two fuses replaced so far.

 

Re: Intermittant cutting off ...where to look first?

I'm with mlew.

Problem definitely sounds electrical, but the fact that PO had to "rev the piss out of it" points to ignition. If it was simply kill switch or safety relay related, it would run mechanically fine after restart.

To eliminate simple things before testing the major components:
Replace plugs
Have battery load tested

It all starts with the battery and ends with the plugs, so eliminate questions in the end points, then start working through the electrical system between those two points.

 

Re: Intermittant cutting off ...where to look first?

Yes- the pick-up coils are the ones where you might see breaker points on older bikes. There is a test procedure in the service manual. Check the resistance with a meter and see what you get. I like to tap on them while reading ohms to see is the readings change, if they do then that's not good.

 

Re: Intermittant cutting off ...where to look first?

Thanks guys....will do.

Might take a bit, as the carbs are on the bench and I'm waiting on a key.

I can test the pick up coils now, though, right? With no power on the bike? What kind of reading am I looking for?

 

Re: Intermittant cutting off ...where to look first?

I wouldn't suspect pickup coils for the same reason as the actual spark coils, they should not fail as a pair simultaneously & it'd likely drop onto 2 cylinders.

Not sure if the specs will be the same on radian, but for XJ you're looking for 650-700 Ohms depending on model (generally though, you're just looking for *some* resistance, not short and not open, they should be OK)

I'd vote for either fusebox, bad connections, flaky sidestand relay if fitted or a cracked solder joint in the TCI...

 

Re: Intermittant cutting off ...where to look first?

I'm leaning towards the TCI. I still need to check the fuse box, but the side stand switch has been replaced.

One thing I can say about the P.O.: The stuff she did replace, she replaced with genuine Yamaha parts. She said she spent more on repairs and chasing this problem than she spent on the bike.

 

Re: Intermittant cutting off ...where to look first?

Wow that's a good sign at least, it's been loved

I'm leaning towards TCI as well tbh, but I'd say make 100% the fusebox contacts aren't crumbling/dropping loose befopre tearing into it. And how about the actual relay for the sidestand? (I guess that would cause the issue only in gear, but we don't know if she tried to start in neutral or not when it cut off so worth a look)

 

Re: Intermittant cutting off ...where to look first?

The fuse box looks surprisingly nice. I cleaned the contacts and the ends of the fuses.
I also took another look around the wiring harness and don't see anything obvious yet.

 

Re: Intermittant cutting off ...where to look first?

i'll second 750E-II_29Rbloke, sounds like TCI to me. Those symptoms are exactly the problem I had, scared the shit out of me...

Those TCI's are old tech, bring em to a reputable electronics shop and get them to clean up any old solder joints and i'll bet a poverty pack you won't get any more cut-outs...

Mars

 

Re: Intermittant cutting off ...where to look first?

They can do that? It looks like a sealed unit to me, but I guess they would know what to do...

I swapped the bars out today for some Super Bike bars and took the chance to look inside the RH control. It looked brand new in there. I sprayed a little electrical cleaner on the kill switch contacts just to make sure.
I also tested it and it Ohm'ed out good.

I'll check the ignition switch when the locksmith gets done.

 

Re: Intermittant cutting off ...where to look first?

If it's like the one's that come with the maxim/seca then they would have to de-solder some pieces to get it apart, but yes it should be doable.

... Checked a few images from internet, looks like a plastic snap-together job, there must be a way to get it apart... Surely someone here has done this deed

 

Re: Intermittant cutting off ...where to look first?

Mind if I switch gears a little to my 84 Maxim400 <20,000km but same problem, died on me yesterday, no starter response at all. Got lights, horn, etc, but just croaked while I was gearing downwards at a red light. Shop manual discusses TCI - is this the ignitor modual under the seat (beside the one with with the cooling fins?)

 

Re: Intermittant cutting off ...where to look first?

Maybe worth starting a new thread, since if you get no crank it can't be the TCI at fault. (fortunately, since the other options are a lot simpler to fix ) More likely flaky fusebox/sidestand switch/relay/safety circuits & relays/killswitch in that order.

If you get a thread going we'll diagnose that mutha for ya

 

Re: Intermittant cutting off ...where to look first?

I took the TCI to a local radio/TV repair shop. I took it apart and he inspected it. It looked as new inside as all of the other electrical components on this bike. Nothing loose, nothing burned.
He pronounced it good, but did put a drop of solder on the areas that he's used to seeing fail on other similar boards/components.

Nothing else to do but try it, I guess. Wish the locksmith would call so I can test the key switch and see if she'll crank.

 

Re: Intermittant cutting off ...where to look first?

When you get it running, let it idle in the driveway for a while with a big ole box fan up to cool it down...

My 650 Maxim would just cut out while warming up, not slowly sputter and die but just like you hit the kill switch and it got worse and worse as the days wore on. Nothing tells you you're alive like cutting out at 65Mph it rush hour traffic :S

 

Re: Intermittant cutting off ...where to look first?

Did you ever figure out what it was?

 

Re: Intermittant cutting off ...where to look first?

My TCI was full of cold solder joints... they were re-soldered and all was fine afterwards...

 

Re: Intermittant cutting off ...where to look first?

His was the TCI, posted in another thread about it

EDIT-: hows that for timing?

 

Re: Intermittant cutting off ...where to look first?

Even though the side stand switch has been replaced, there is a side stand switch relay. Is it possible that there could be something wrong with the relay that would cause these symptoms? Is there a way to check that?

I'm probably getting a little ahead of myself. I'm still waiting on the locksmith and haven't been able to test much else right now. Just thinking aloud/ahead.

 

Re: Intermittant cutting off ...where to look first?

Check out http://www.erd.co.nz/index.html for a replacement TCI unit, Ive got the same problem with my XJ750E-II; Starts fine and will idle for 3-5 min then just dies, most of the time it starts up straight away and after 3-4 times of stopping is then fine.

 

Re: Intermittant cutting off ...where to look first?

Cool. Nice to have an option out there. Any idea on pricing? I don't see anything on the website.

 

Re: Intermittant cutting off ...where to look first?

Welcome to the club 8O 8)

I don't think it'll be the TCI now it's been looked at. You can check things like the sidestand & safety relay most easily by substitution when the bike stops IMO.

 

Re: Intermittant cutting off ...where to look first?

One more possible culprit in the equation:

I pulled the alternator cover today to swap it out for a finned one from an FZ600. The rotor face was FILTHY. I couldn't even get an ohm reading across it.
Cleaned it with 600 grit and some electrical contact cleaner (sprayed on a lint free shop towel and wiped off...I didn't spray anything on the stator winding) and tested again. I got 3.8-3.9 ohms both ways then.

The brushes are like new. I'm wondering if between that and the dry battery, the charging system wasn't struggling to keep up? Maybe it was sending voltage to the battery and robbing the TCI and other electronics of the proper voltage to function?

The battery, which took a charge, has been sitting on the garage floor for about a week now. It still shows 10.8 volts, which is low, I know. I'll have it load tested and try to use it to at least fire up the bike. I'll probably replace it eventually.

 

Re: Intermittant cutting off ...where to look first?

Leaving a Battery on a concrete floor will cause the battery to discharge quickly, one of those freaky things of nature, thats why all battery shops have them on racks.

 

Re: Intermittant cutting off ...where to look first?

I heard that was an Urban Myth.

 

Re: Intermittant cutting off ...where to look first?

It's not a myth but it doesn't happen any more.

That was true of the old, hard-rubber case batteries of the '40s and '50s. Modern batteries with plastic cases don't have the problem.

 

Re: Intermittant cutting off ...where to look first?

Ignition switch tests OK. I may just charge up this old battery and rig up a gas source and see if she'll run soon.

I don't have any mufflers on it right now, so I'll wait on that.

The entire gauge cluster/idiot light panel is off the bike. Does any of that have to be connected to make it run?

 

Re: Intermittant cutting off ...where to look first?

The discharged battery on concrete still happens. Battery manufacturers changed to plastic cases to save money. Besides, since when does plastic make a better insulator than rubber? They may have changed the chemical composition to slow the discharge, but it still happens.

 

Re: Intermittant cutting off ...where to look first?

Still wondering about the relay....possible culprit? Way to check it?

 

Re: Intermittant cutting off ...where to look first?

You could bypass the relay and switch to see if the problem goes away.
I think the TCI is the culprit, maybe the guy that checked it overlooked something like a connection that comes loose under heat.

 

Re: Intermittant cutting off ...where to look first?

My problem was the kill switch was acting up and was cutting out randomly. Took the switch assembly apart and cleaned it with electrical contact cleaner. Works fine now.

 

Re: Intermittant cutting off ...where to look first?

You can do Relay Troubleshooting with one of these 9-Volt Battery Pigtails and a Multi-meter.

 

Re: Intermittant cutting off ...where to look first?

You know, I thought of something last night....

I was reading the tech section in Cycle World and a light bulb went off in my head.

I posted in my build thread about the gas cap and tank condition. The locksmith had to get all gorilla on the cap to get the lock open (putting yet ANOTHER dent in my tank! Grrr!!!... ).
The tank has a failing Kreem liner and the cap was stuck, broken, rusty and has evidence that Kreem may have gotten in and around the cap.
I guess it's also possible that the vent on the gas cap was plugged, either with rust or Kreem, and the tank wasn't venting. This would cause the running out of gas....stopping for a while...then cranking back up issue. Yet another piece of the puzzle, maybe?




I'm looking for a better tank, but my body man can save this one and he has a radiator shop that can boil out the liner.

 

Re: Intermittant cutting off ...where to look first?

Plugged gas cap vent don't use to cause the engine to suddenly cut off, usually. It is more like sputtering adn finally die, just like when the bike runs out of gas.

But this could be a fair part of your problem.

 

Re: Intermittant cutting off ...where to look first?

What if the loose sealant is clogging the in-tank filter. A sudden stop of fuel flow would cause it to shut off.

When I was a kid, I pranked a man down the street with a ping-pong ball in the gas tank of his car. He would go down the street til the ball would clog the line and cause the motor to stop. After a while and a lot of cussing, the ball would float back to the top allowing the car to crank til the process started again.

I'm lucky to still be alive. LOL

 

Re: Intermittant cutting off ...where to look first?

The filter on the petcock was clean and intact. I've cleaned and rebuilt the petcock.

 

Re: Intermittant cutting off ...where to look first?

What I was thinking was that maybe a loose piece of liner is wrapping around the filter then letting go after the cutoff. Once you get the tank cleaned out, hopefully the problem will go away or at least rule that out.
Is there a way you could rig a temporary tank and see if it still happens?

 

Re: Intermittant cutting off ...where to look first?

As soon as my mufflers get here, I'll rig up a temporary tank to at least crank it in the garage. Don't have a way right now to rig one up that would allow me to ride it.

 

Re: Intermittant cutting off ...where to look first?

Anything that is blocking the gas is just going to give the same symptoms of fuel starvation/running out of gas.

Sudden cutoff points more to electrical. I'd look at main fuses, then towards TCI-coil-plug directions

Dave F

 

Re: Intermittant cutting off ...where to look first?

I agree, Dave. So far, I haven't found anything wrong. I hope to get it running soon and continue the search....

 

Re: Intermittant cutting off ...where to look first?

On another bike the vent in my cap was blocked. The stoppage was final and no spluttering beforehand. Lift lid en -route and away it went again...easy to test

 

Re: Intermittant cutting off ...where to look first?

On another forum it was mentioned that "a common problem with these bikes is the ignition pick-up magnets losing magnetism, whence the bike "cutting out" or just failing to start without a perfect charge on the battery. Might be worth looking into."
Ever heard of this? Is there a way to test it? Does the bike need to be running to test the pick-up coils?

Also, someone mentioned bad coils. I know how to test between the plug caps using an ohm-meter. What kind of reading should I be looking for on these coils?

 

I'm having a hard time testing between the plug caps. I need another set of hands.

I unplugged the coils and tested the wires at each plug. I get 3.0 Ohms, minus the resistance if my meter, so about 2.8-2.9 ohms.

Shouldn't I be able to test from plug cap to plug cap and get a reading, too?

Also....still looking for info on checking/testing the magnetic pick-ups.

 

Anyone? .... :?

 

REPLACE THE FUSEBOX!.
Despite how it looks, these fuse boxes are not reliable, especially when 30 years old. When they heat up, they can lose contact. Also, the fuses can actually lose contact with the holders. Fuses can actually vibrate loose from the clips. They can slide out of contact. Replace the glass fuses with an ATM fuse block.

 

Does anyone make the ATM block specifically for these bikes? With the correct plug, etc.?

 

There is nothing specific to the bike. Any block which fits the space will work. As I recall, Chacal sells one that works. Ideally, get one which has a water tight cover. I ordered the ones I used off the internet - I don't recall where.

 

Just don't' use one with a common buss....unless you like making wiring looms.