New member needs a bit of advice -Thanks!

[magicvideo1]

Hi,

My name is Robert . By way of introduction, I am a new member living in Mississauga, Ontario, Canada. I commute to downtown Toronto on a motorcycle about 10 months of the year aided by electric clothing in winter and motivated by free parking for motorcycles in downtown. I would be curious what other major cites allow this? For what I save in parking, I have convinced myself to "reinvest" the money I save in motorcycles. I now have about 14 in the garage at last count. (and no, my wife is not happy about it).

For those interested, I have a '71 Motoskeeter Mini (my first bike), a '71 Kawasaki H1 500, '72 Kawasaki 750 H2, , '75 and '77 Goldwings, '77 Hondamatic 750, '77 Suzuki GT750 Water Buffalo, '82 Honda XL500, '85 Kawasaki Turbo, '87 Honda Transalp, 2 Honda Pacific Coasts (one with a Tow Pac trike kit) and a '95 Virago. Of course, "the jewel in the crown" is an '81 CBX. I acquired it a few years ago from the original owner . It has 16000 KM on it or about 10000 miles for my American friends reading this post.
I have had it a few years now and have now finally cleared a path to it in the garage to work on it.

I have browsed the forums and I wonder if someone may be able to advise me about my first snag in bringing this bike back to life?
After going through a cautious pre-start routine that included changing the oil and filter, oil into the cylinders and rotating the crank by hand the bike started right up and seemed to idle and rev normally. The previous owner had a Honda dealer rebuild the carbs shortly before parking it. I have a receipt to verify this work was done The exhaust is a 6 into 1. The previous owner said he was never satified how it ran after the carb rebuild.( I have yet to see what he means by that).

So that day I started it a few times and left it to the following weekend when the bike would no longer start for some reason. I did confirm that fuel was reaching the carbs and I shut the garage door and put the spark plugs, in turn, on the cylinder heads and confirmed that I was getting spark on all cylinders . Albeit the spark look very weak? As my first CBX I don't know how strong that spark was supposed to look though. The only other detail that I can add is that I "think" I may have heard a "popping" sound from the spark units while I was trying to start it. I think the sound came from the spark unit as I had the seat off the bike while attempting to start it. I have read some of the posts here about the spark units being prone to failure especially if the bike has been stored for a considerable amount of time. My question is if the spark unit or units (I am not sure which terminology is correct ) failed would I still see spark on all cylinders? Would one of these units make a popping sound (like your favorite TV tube when it dies?).

And finally, I am considering replacing the system with the Dyna ignition instead of chasing electric gremlins. Someone has one on sale on right now that includes the coils and plugs wires at a good price. Would someone advise that is the way to go at this point? The truth I am not the best at diagnosis with a multimeter, but at the same time this is a lot to spend . I am trying to justify it as it couldn't hurt to replace the 30 year ignition at this point, but I would like someone to agree with me here.
Any insights on what the actual problem may be or what to check next would be most appreciated.

Sincerely,
Robert

[Don]

Welcome to the forum! - You have a much more understanding wife than many of us I suspect

There is nothing wrong with the stock CBX ignition. It's an electronic system (like the Dyna) so assuming you have a fresh battery, if you have any spark at all you likely have all the spark they designed into it. The Dyna system is just something for the few who are obsessed with wringing the last possible horsepower out of the engine. Buying a Dyna and putting it on your bike isn't likely to make it run any better than it does now . . . . you need to investigate why it isn't running and fix what is wrong. Buy the Dyna if you really want it, but don't expect it to make a sick running CBX run any better

Have you had gas sitting in the carbs since you bought it, or did you fill the bowls for the first time when you started it? The usual problem with CBX's that sit for extended periods is usually with the carbs . . . . the gas evaporates and leaves behind all the things that the enthanol in our gas encourages to grow. There are several guys here who will help you get to the bottom of your current problem

Don

[steve murdoch icoa #5322]

I have a Dyna ignition and coils, Taylor spark plug wires and a new agm battery on my '81. I find that it starts quicker and easier than the '79.
Of course there are many other variables that have to be included but it is also one less thing to have to worry about when trying to eliminate troubles.
Getting rid of the black tar dripping spark units is also a plus.
Like Don, i think your carbs are probably the source of your troubles.
Had it been sitting for a long time before you started it? New gas? Auxiliary tank?
BTW, strictly for my record keeping purposes i will need your address and exactly what time you leave for work.
Great collection of bikes.

[oilheadron]

(BTW, strictly for my record keeping purposes i will need your address and exactly what time you leave for work.)

[EMS]

The Prolink (81 and 82) spark units were much improved from the 79 and 80 and usually don't leak black ooze. They are also located in a much less problematic spot and get more cool air than the earlier ones.
I have the original spark units on my 81 and have re[placed the 79 and 80 units with the Prolink units (you need a special pig-tail harness for that) and do not have a problem with them.

[magicvideo1]

Thank you to everyone who has replied, so far.
I did remove the gas tank and used fresh fuel and an auxiliary fuel tank and fed the carbs directly on start up. I just hit the button once and it fired right up. (The gas tank was dry for storage). That said, there was old fuel in the float bowls- at "least" a few years old. I know I am going to get in trouble for this but the old gas in the float bowls "did not smell that bad" I remember thinking to myself at the time.
I am trying to not to let myself think that the bike just allowed itself to start and run once and then whatever was in the old bowls managed to plug everything up and not start again!

Thanks for clarifying that the spark units are in a different position on the later model bike and and that the black oozing is not a problem on the later units- as they looked very clean on mine.
I think I did hear something audible like a"pop" from the spark unit so that is what made it suspect something in the ignition may have failed. I appreciate the input about the reliability of the stock ignition. My hope perhaps unrealistic in that an new ignition would magically solve my problems and get the bike running again. It is amazing how this bike that has been sitting there in the garage and been an obstacle that I have been routing my garden hose around is now so desirable to hear running again.
I look forward to any advice on what to do next.
Thanks,
Robert

[FalldownPhil]

Spray a little quick start into the intake of the air cleaner box and then try to start it. That will give you a real clue as to whether it is a fuel or ignition issue.
My money says it will fire right up, briefly Also, be sure that the kill switch is in the run position. If it starts or tries to, it is most likely a carb problem.
Best,
Phil

[magicvideo1]

Hi Phil,

Thanks for you input. In fact, while documenting the start up procedure I "completely" forgot to mention to everyone that I tried the starter fluid in the air box until you reminded me! And nothing, not even a short "run on" like you would expect! Does that lead you to conclude it is more likely an ignition issue?

[FalldownPhil]

That certainly adds credibility to the possibility.
Phil

[Don]

*Usually* ignition problems only take away 2 cylinders and the bike will still start and run . . . . but roughly as it's only running on 4. There are 3 of everything in the ignition system - Pickups, spark unit and coils . . . . a failure of any one of those and you have a 4 cylinder CBX. It's pretty unusual for an ignition failure to cause the bike not to run at all . . . . especially since you say you have spark and it was running a week ago

The bad gas sitting for extended periods of time in the float bowls is usually the problem. If there was any ethanol laced fuel in there, it can actually cause green gunk to *grow* in your carbs. My carbs were completely rebuilt and then when we took them apart 3 years and 7,500 miles later you would be amazed at all the green crap in there . . . . it still ran, but wouldn't have for too much longer. I religiously drain them now anytime the bike sits for very long

If your bike has set for an extended period, likely the accelerator pump is kaput and that does make it harder to start - If it is still working, 10 or 12 twists of the throttle will 'prime' the engine and it should fire right up with the choke on. Since you had it running a week ago and you see spark on all 6 plugs, it's *probably* not the ignition . . . . but you never know

There are drain screws and hoses on the float bowls - 3 on one side and 3 on the other. Drain them anytime the bike will be sitting for more than a couple weeks

Don

[magicvideo1]

Hi Don,

Thanks for your insights regarding the the fact the the bike "should" still start and run, albeit roughly as opposed to not at all if it was a ignition problem. I will trying priming the engine to see if that make a difference in getting it started back up .
Again, it was that popping sound I heard from the spark unit that had me convinced that "something must have "cooked" leading me to think ignition- perhaps falsely in this case. I will then look at the "on bike carb" clean method first. I will keep everyone informed as to how I make out.
Many Thanks!
Robert

[magicvideo1]

Hi,

It has been a while, but my CBX is now running on all 6 cylinders though not driven yet . Thanks to everyone for their insights. (Just in time for winter storage -unfortunately).
I do have two questions to ask at this point . With the gas tank off , and the carbs fed from an auxillary fuel tank, the bike only wants to start if I blow air with my mouth (like inflating a balloon) into the fuel line while I crank the starter. Is there some type of diaphragm on the carb that is not functioning properly?
Secondly. I fed a mixture of fuel stabilizer into the carbs for winter storage. Do I need to do anything else to keep the carbs clean over the winter. That is, do I also need to drain the floats bowls or can I leave as is and depend on the stabilzer ? I don't want to pull the carbs again in the spring

Thanks, again.
Robert

[EMS]

Your 81 CBX has a vacuum valve between the petcock and the carburettor inlets. Gas will not flow into the float bowls without the valve open. Cranking the engine usually provides the necessary vacuum. Using an auxiliary tank or the bike's tank should not make a difference.
As far as the storage with stabilizer is concerned, the opinions differ.
I use stabilizer in the fuel and make sure it has reached and filled the carbs and all jets completely. Some others swear by draining the carbs.
Both methods have pros and cons and the potential for problems next spring.
I am storing 17 bikes currently and 13 of them are carburetted. I have not had a carb problem the last 5 years

[magicvideo1]

Hi EMS,

Thank you for your response and sharing your experience with Fuel Stabilizer over the past number of years.. (You have confirmed what I thought ; the fuel source should not make a difference. That is why I thought it would be prudent to feed the fuel Stabilizer directly into the carbs as I did not want to fill the tank with stabilized gas and not have the bike start
That said, are you saying the you believe the vacuum valve has malfunctioned? Can they be tested or if need, be replaced?

[EMS]

Hi EMS,

That said, are you saying the you believe the vacuum valve has malfunctioned? Can they be tested or if need, be replaced?

Robert: If you cranked the engine and there was no flow of fuel to the carbs, one would have to assume the valve malfunctioned. I never had the need to test one, but one way would be to apply a vacuum to the respective line and see if there is fuel flow through the valve.
If you need to get fuel into the carbs now, you can always bypass the valve.