Ignition Trouble - Maybe? - Please Help

I think I may have some ignition issues.

The bike will crank with a LOT of trouble. Once running it runs REALLY rough, like the cylinders are not firing correctly. I just put new carbs on, fresh, clean, double checked and everything looks good. The bike is getting plenty of fuel as the exhaust (when I can get the bike running) is putting out black smoke. I am running pods on the carbs, and standard jetting. I pulled the plugs and they are all gas fouling really bad. It seems like the fuel isn't igniting until the mixture gets ultra rich, then it may or may not combust. When I first threw the new carbs on, cylinder two wouldn't fire, exhaust was warm at best. The plug was gas fouled horribly, as the other three were kinda nasty. Went and got brand new plugs, pulled the carbs to check the bench sync (all good), checked float height (all good), put brand new plugs in and the bike was still burning a ton of gas. Started messing with the fuel mixture, but that didn't help anything. I started checking for spark and sometimes I can get a weak yellowish spark, and sometimes I get no spark. Put the plugs back in and try to fire the bike up again, now Cylinder 2 gets nice and hot but the other three are dead.

I was all set to buy new coils and such, then decided to test to Ohms on the coils. I check the Haynes manual, and the diagram shows the meter set to Rx1 for the low side, and Rx100 for the high? That doesn't look right (I don't begin to know how to work an Ohms meter) but I try the coils. The ohms are way off, so I put it over on Rx1000 which would make more sense? The coils test right about 12K Ohms without the plug caps, and the caps read 5K and 9K Ohms (1-4 read the same and 2-3 read the same). The low side of the coils on the meter read just BARELY a HAIR above 2 Ohms on the meter.

Now the book says 2.5 Ohms on the low side +/- 10%, so that means 2.2-2.7 Ohms is a good range. I think mine might be a smidge, and i do mean a smidge low, like, really close to 2 Ohms. Could this cause my problem? I have not tested the TCI, and the problem seems to be intermittent and completely independent of the coils themselves.

I have had other issues with getting the bike to start, and issues while the bike was running. When I got the new carbs, the bike wouldn't crank at all. I thought the gas flow was blocked so how, but it wasn't. Gas was flowing fine. On a whim, I pulled the main fuse and then put it right back in. The bike cranked on the first try, fired up and was ready to go. It was burning gas bad and running kinda rough, but would idle pretty good.

Before I got the new carbs, it would run, but not right and only on three cylinders. This turned out to be due to the carbs, but I had ridden the bike a bit around the neighborhood. A few times, the bike just.. died. Like I cut the kill switch. I could NOT get the bike started, it would just spin like it had no gas or no spark. I killed the ignition (cut off the key) wait a count of twenty, and try to turn the bike over, it would crank right up, run for a count of maybe thirty or so, then die. Same deal, free spin, cut the key, try again and it would crank. After about fifteen minutes of this (I wasn't about to push the bike 3 miles back to the house) it finally cranked and kept running (pretty strong too) all the way home. Parked it and let it run, went around the block a dozen times, didn't flake out again.

It was right after this I discovered the problems with my carbs, and the bike got parked for a good month.

Compression on the cylinders seem quite good, between 150 and 200psi. I am very close to finding someone to look at it for me, as I just am not sure where the problem is.

The bike was not running ultra rich before the new carbs, and they don't seem to have any problems.

Any suggestions?

 

Checking the carbs was a good move. Almost sounded like flooding due to a bad float needle or something, so it's good that you checked the float heights. No sign of gas in the oil, or in the airbox?

Assuming the carbs are good, the weak- to no-spark sounds like a problem. I thought 11kOhms was right for the coils. Sounds like you're using the meter right. You have to watch it on the low end (2 Ohm measurement) because the meter leads will have an ohm or two themselves... you can usually short your probe leads and zero the meter to compensate for this.

I've had a dirty kill switch that caused issues like you were having. It basically *is* cutting the kill switch. Took it apart and cleaned the contacts, problem solved.

200 psi almost seems too good/too high to me.

This is a good point... there may still be a problem with the carbs. Are you 100% sure they're clean? Nothing blocking air jets or reassembled incorrectly? When you said "new carbs" does that mean you didn't do the work yourself? Always be a little suspicious in these cases...

 

Have you tried going through all the electrical connections associated with ignition ie: clean and lube connectors. Good grounds are escential since the charging system is barely acceptible. Next is the fuse block. It is worthless and extremely prone to failure. It has poor conections due to the inferior metal used and usually will crack when inserting a new fuse and you won't even notice it happened. The saftey ckt (kickstands and clutch sw) interupts the starter sol. so you must be ok there since the starter always works. Remember...intermitant electrical problems are almost always a poor connection some where.

 

Thanks for the reply.

@Chazmati:

I pulled the control with the run switch and checked the solder (since the left control was bad) and it *seemed* to be ok, but I don't mind pulling it again to check. When checking the compression it had been sitting for a month and the motor was very dry. The compression was incredibly low. I put a VERY small amount of oil in the cylinders and the compression came up to those levels and has not dropped. By small amount i mean a small amount, like maybe a teaspoon, if not less. (I read that adding a teaspoon of oil will give you better readings if the cylinders were really dry)

The carbs I got off ebay, and I pulled them apart the second I got them. Originally there WAS fuel leaking into the PODs (I put them on the bike before noticing the missing parts), but there were a couple parts missing, namely there are some jets located in the "horn" on to each side of the opening. Carbs 1-3 were missing these jets, while carb 4 had both. I took the jets out of my old carbs and put them in the new set, and it seems the fuel stopped leaking into the PODs. I didn't completely take apart the carbs, but I took a peek under the diaphragm and in the float bowls and everything seems fine and clean. I will tare them down fully today after work just to be sure.

@seaguy:
I haven't gone through every connection as of yet, but I have a feeling this may be part of, or at least one of the problems the bike has. I don't know if it is causing this particular issue, but I have gotten a few shorts before that I traced down and found bad/corroded connections. I completely replaced the fuse box, as it was rusted so bad that when I went to change a fuse the fuse holder just crumbled. I cut all the wires (making sure to do the one at a time so as not to cross wires) and just wired in four blade style fuse holders. I don't think the safety switches are causing issues, because as you said, I have yet to have issues engaging the starter, and when the bike does run, those safety switches work perfectly.

I will check the connections and check the rest of the ignition system, as well as pull the carbs and take them apart fully and double check everything again.

Any other suggestions would be very welcome.

 

have you tested for spark on all cylinders? pull each plug and test one at a time: pull the plug, plug back into the wire, ground to the engine, engage the starter. you should see a spark and hear a "snap". if they are all good then you need to look at your carbs again and couldn't hurt to check valve clearances. if the spark is not there or is weak then you need to look into the ignition system more. let us know how it goes.

cheers,

Trev

 

Another thing to look at is the jets you are presently using. They may have a stock size number on them but you really won't be certain until you gauge the holes. #120 means a .12mm hole etc . There are tiny drills that are very close but you need a mic to check them. The ebay seller or carb PO may have drilled the stock jets since some of them have be messed with. Bottom line is: you have to know what you have. The Hitachi CVs are not at all forgiving.

 

Thanks again guys!

@tibor:
Indeed I did this, pulled the plugs one at a time put the plug wire on and grounded the plug. Spark was intermittent and seemed weak. The spark on the plugs before I parked it waiting for the new carbs was nice bright blue. The spark now (when I get a spark period) is a weaker yellow/orange spark, and you can't really hear the spark now, when before you could hear the crisp snap of the spark.

@seaguy:
the jets "look" to be fine, I replaced the pilot jets with my old one, but the main jets the guy put in this carb are plastic. They are marked as 110 (stock for the 82 650RJ), but who knows. I was going to replace them with my old main jets, but I couldn't get them to come loose and didn't feel like ripping the carbs apart to get the inner tube to stop spinning so I could get them out, so I put the carbs on as is.

I am gonna play with the carbs again when I get home and hook everything back up and see what I can see. Might drain the oil and see if it has gas in it, couldn't hurt to go ahead and change the oil again.

 

i think it would be a good idea to make sure you have good spark before pulling the carbs again, check for voltage/ohm readings right at the TCI, that might indicate which connector is bad. also check for power right at the coils and check all the ground connections (battery, TCI, regulator, etc).

cheers,

Trev

 

nickel, we'd all hate to see you spend too much time on this. We all hope this forum will help you quickly. we all know a Colortune plug is for fine tuning but it ended up helping me figure out my ignition trouble. It's a good multipurpose tool and the 70 bucks or whatever it is should most definitly be worth your time. Good luck. it won't be adding another factor to your problem, using it is a no-brainer. just my 2 cents

 

Soooo, I have a little bit of information I'd like to share and see what you all think.

My father was messing with the bike before I got home when I first put the carbs on. He hooked the fuel line and vac line backwards, put the switch on Primary (because he refuses to accept the fact that the tank works off vac and says that it MUST be set to PRI) and he emptied a half gallon of gas into the VAC fitting on carb three. He said it was running out all over the motor before he realized it was leaking. So he swapped the hoses and said nothing.

He decided to tell me this when I mentioned that I was planning on checking the oil for gas and changing it out.

Sooooo, my question now is, since there is a LARGE possibility that the oil is full of gas, would that thin the oil and cause the blue/black smoke im seeing now?

(I still haven't checked the oil, I will be doing that tomorrow, work has been keeping me busy, just fishing for info here really.)

 

Damn! Well, that's good to know. Sorry to hear it!

 

Take the oil cap off and sniff. if you smell fuel change oil and
filter.
Also... Checking for resistance is not a sure test of the coils.
That will not tell you whats actualy happening as the coils are firing.
Have you pulled them off to check for cracks in the coil bodies?
They could be arcing from any point down to the plugs.
A prob could exsist in the primary or secondary winding that may
be producing a weak but visible spark.

 

This Members situation is a PERFECT Example of why you should have a Factory Workshop Manual to assist you with making adjustments and repairs.

"The Book" answers the questions that pop-up while you are dealing with an unfamiliar set-up.
Settles arguments between Father's and Son's.
Shows you what something is and how it works.

Makes working on the Bike less anxious about what to do.

There are Troubleshooting Guides for every situation.

Contains Illustrated Photographs that will help prevent the incorrect hook-up of Fuel and vacuum Lines.

Saves you money every time you look-up how to something yourself.

 

how did he swap the lines in teh first place. cuz one line is twice the other line. LOL.

one won't fit. and the other is going to be so loose you'll have a serious vacuum leak.

 

I don't know if the fuel line is original or not, but it fit pretty snug on the vac line. I think it may not be the correct 1/4" line. I am planning on fixing this too, I have the line already.

The old man is getting up there, and he sometimes does funny things. To his defense, the two lines that are on there right now could be rather easy to mix up just by looking at the size of the hose.

I'm just glad I decided to check a few more things before spending a crap load of cash I might not have had to spend. I picked up a cheap little multimeter the other day and will be testing all the connections for the right voltages and such.

 

When you have a father that is interested in the project, ... letting HIM read the Service Manual helps to get things done.

The read the thing from cover to cover and TELL you what you should be doing next.
And, ...

HOW to do it!

 

Well, there was gas in the oil. Reeked of the stuff, and the oil was quite thin. Changed the oil and fired it up, a LOT less smoke, still a tiny bit when I hit the throttle, I will probably need to change the oil again.

I still have ignition issues, one cylinder will not fire. I swapped the coils (coils for 1&4 moved to 2&3 and vice versa) and now cylinder 1 doesn't fire, where cylinder 2 used to have issues. So, the issue seems to follow a certain plug wire.

More testing to come.

@Rick:
Yea, I have read about 60% of the Haynes manual, a lot of misinformation in there. I need to spring for the factory manual, but 80$ for the book is steep. Maybe one day soon.

 

As much as I see Rick's point reguarding the legalities of
the xjcd-I feel no saddness that yamaha may lose some
money on a 25yr old manual.

Go to the stealership and order a few OEM parts!
Yamaha has ridiculis prices and no it's not to cover the few
dollars lost on things like our cd-It's because they want
profit and if you can't afford their prices-hit the road.

Get the XJCD-it's cheep, It's great. This is Your bike now,
not yamaha's.

They don't care whether that old xj runs or not-they have
the v-star line to worry about.

 

So, further testing done on the TCI, checking voltages and such, and it all looks good. All the connections seem fine as far as I can tell. I hooked everything back up and fired the bike up. Cylinder one doesn't fire, all the other cylinders are firing, but the bike is running really rough (which is to be expected since one cylinder isn't firing).

So, my question now is, should I attempt replacing the plug wires on my current coils (Coil Surgery), buy a couple new OEM replacement coils off ebay for 35$ each, or just pony up the cash for a set of Dyna coils?

My father is still fighting with me about the bike. He is telling me to go to auto parts and buy coils for a car and just use those. He said its cheaper and all coils are the same.

So, any thoughts? Anything else I should check before I swap coils?

 

If you have the dough for New Coils ... pop for Dyna's and some good wire.
Easy.

If the Old Coil just needs Wires.
Go for the Coil Surgery, ...
It's messy ... but, new wires are easy enough to install.

Ebay?
You night wind-up with Coils that also need surgery.
But, the Coils with new Hi-tech Wires will be good spares.

I want to switch-over my Wires to yellow or red.

 

So, I still haven't had the cash to buy new coils, but a friend told me to hold off before I buy the coils. Told me to check the stator and see if its generating the correct voltages to fire the coils, because since the bike has a wet stator and there was gas in the oil, the stator might be bad.

Is this a possibility? I REALLY do not want to spend money on parts that aren't needed.

Could the gas in the oil cause the stator to go bad (gas was in the oil for a good week or two before it got drained.)?

Could a bad stator cause weak or intermittent spark?

 

I turned 62 Years old last week.

I have never encountered Gas in a Stator.

Never heard or read about it until moments ago!

Off hand, I'd say ... The Gas-soaked Stator is shot.

 

I don't KNOW if the stator is good or not, haven't even tried testing it yet, or looked up HOW to test it. He said that gas eats plastic, and the stator is plastic, so the gas in the oil would have eaten the stator up quickly, since the stator on my bike is wet.

I don't know anything about this, i'm just parroting what he said, but the problem did start after the gas had been in the oil for about a week or so.

 

Update: Tested ohms on the stator, and all the white wires coming from the stator ohms out in spec (between .4 and .5 Ohms). Tested the green and brown wires from the rotor, and it ohms out at 16ohms. The Haynes book says it should be 4 Ohms, but the Haynes book is crap, so I wanted to verify that this was out of spec.

Started swapping spark plugs and wires around, seems one cylinder will not fire, and this problem follows the plug, not the wires. Cylinder 1 wouldn't fire, I swapped wires on cylinder 1 and 4, and cylinder 1 still would not fire. I swapped plugs between cylinder 1 and 2, cylinder 1 started firing. So, I'm thinking I have a bad plug, again. Seems every time I buy plugs I end up with at least one bad plug. So, I can crank the bike, but it runs really rough and won't idle without a little throttle. Also, it seems to surge. I kept the throttle steady sitting at about 3.5K RPM, and the bike would surge between 3.5K and 4K RPM.

I am going to do a new bench sync to be sure its good, and i'm going to pull the carbs apart and see if I can find anything weird. I am going to remove the plastic jets and replace both the emulsion tubes and jets from my original carbs.

I am REALLY close to purchasing a color tune plug, does anyone have any suggestions one where to get a good color tune off the net for a good price?

 

Way to high. The specs in the Haynes book are correct. Might have some bad alternator brushes, pull the gen cover, inspect brushes, take ohm readings on the rotor itself to verify.......

 

Will do!

Question: The Voltage at the TCI should be between 12 and 14V correct? Depending on the RPM of the engine (Haynes book says 14V @ 5k RPM). Where exactly do I test this at? I am a little confused as to where I need to put my probes.

I swapped all the parts from my old carbs (less the pilot mixture screws) into my new set, noticed that the pilot jets in the new carbs had a larger hole than the jets in my old carbs, even though both were #40 jets. Could these have been drilled out and causing the gas fouling of my plugs and the smoking? It still seems like i'm flooding or something.

 

Update: Swapped all the parts from my old carbs into the new set, put them on the bike, was a little easier to get cranked but still had some trouble with a cylinder not firing. So, I took another set of plugs I had laying around that had been gas fouled, cleaned them really good, and replaced the plugs in the bike with these. Fired up and ran pretty smooth, with a little surging and when I rev the bike, the revs stay up for a couple seconds then slowly fall back to idle. I checked the throttle linkage a dozen times and it doesn't seem to be hanging up.

So, I think my ignition problem was due to a bad set of plugs from Auto Zone. Changing the parts in my carbs out stopped my smoking exhaust problem. Now i'm down to the surging and rev issue. Which I believe means that I am running rather lean yes? Which would make sense, I have stock jetting and cheap pods on the bike, plus my idle mixture screws are setting at 2 turns out. (I will continue with the mixture tomorrow, it got too dark and mosquitoes were trying to carry me off)

 

I will say this, I didn't read the whole thread, But, hanging idle is one of two reasons; friction of the carb pistions and/or in need of syncronization. 2nd note, 2 turns is no where near enough out, without pods you should start at 2.75, with, it'll be Alot more, but, you'll probably need to jet. Chacal's catalog section in his thread has the standard rules of thumb to get you the right jets or at least in the ball park. with the right jets, your mixture screws should be between .75 and 3.5/4 turns out, on Most machines - as I understand it. carefull, don't run your bike that much right now. I'm guessing a Colortune will save you a massive amount of hours for your next step

 

I ordered a color tune, waiting for delivery.

One thing I did notice, on the cylinder that wasn't firing, when I swapped the plugs and it started firing again, it didn't get hot immediately like the others. It took a little longer but it slowly warmed up and got hot. Once it did the bike seemed to idle a little less rough.

The bike is on the side lines for now. I only crank it to tune and thats in short increments.