oh so close. . .

[williamruck]

OK, so here I am. I got everything put back together and I have just tried to start my Vision. The bike turns over, I can see fuel moving through the inline fuel filter, it fires occasionally, gives a little glimmer of hope then quits. Now, I am sure that I flooded it off the bat, that is not what I am asking about. As it is turning over and firing I hear an alarming clunk coming from the engine and I am not sure what it is. Any ideas?

[Walt_M.]

Did you do the starter clutch mod?

[Rick G]

Could be a loose ballance shaft nut too!

[kwells]

Well yeah could be the above things...sometimes the backlash from it not firing will give that clunk.  I wouldnt worry about it just yet though. 

When you say back together...What was taken apart?  What was fixed?

[Lucky]

very normal if cranking amps is getting low.  jumping off a NON RUNNING car will help, then it's just a matter of finetuning the pilots & synq, & choke sweet spot.

you are close!

--Lucky

[dj]

What is the battery voltage at?  Needs to be above 11 volts while cranking or the starter motor wont turn fast enough to engage the starte clutch.

How do the plugs look?  Could just be slightly dirty plugs (weak spark).

[YellowJacket!]

Mine makes the clunk every so often.  Ususlly if my battery is low.  YJ seems to like nothing less than 12 volts.

David

[williamruck]

Did you do the starter clutch mod?

No, I haven't. Is there something in the technical section about it?

Could be a loose ballance shaft nut too!

Is that something I should check before I proceed?

When you say back together...What was taken apart?  What was fixed?

I reconditioned the gas tank, replaced the fuel lines and installed an inline fuel filter, I took apart and rebuilt the starter, and I had the carb rebuilt as well.

very normal if cranking amps is getting low

The battery was starting to get low, I need to put it on the charger.

How do the plugs look?  Could just be slightly dirty plugs (weak spark).

I just replaced the plugs and checked the resistance in the wires, caps, and coils and they all checked out. From what has already been said I am thinking it might have a lot to do with the battery but I want to rule out anything else as well.

Mine makes the clunk every so often.  Ususlly if my battery is low.  YJ seems to like nothing less than 12 volts.

From what has been said so far that is what I am thinking it is, although I do want to check out this starter clutch mod as well as the possibility of a loose balancer bolt. Thanks for the advice guys.

[kwells]

yeh...well...dont rule out the carbs JUST yet.  They could still offer some trouble since they tend to need to be cleaned out a couple times.  But you are close.

[williamruck]

Well, I am going to say that the clunk noise was a product of a low powered battery. After I let it sit on the charger for a bit the engine turned over a lot smoother. BUT, I seem to have a new problem.  :'( When I push the start button I am back to getting nothing at all. Now, I have tried jumping the solenoid and the starter will start to turn the engine over, and I have also attached a hot lead to the starter and that has caused it to turn as well which leads me to believe that there is something wrong with the ignition system leading up to the solenoid. Am I wrong in assuming that? Also, is there a diagram for the ignition system in the technical pages?

One step at a time I guess.

[jasonm.]

you can get clunks "while" starting from the starter clutch slipping. = nothing broken. Clunks as it is running is 90% starter clutch(behind flywheel) loose. If you actually get it going and it clunks with oil pressure light off. Then the clutch must be refastened(new bolts and red loctite)  before you attempt to ride it. I know of people who have sold and bought these for just this simple issue. I suspect the last owner knew about the noise and never had an idea it was the starter clutch. The reason these would loosen was mostly due to NO loctite being used on the bolts. Get a manual. You only need a few tools. And maybe you can go to the yamaha parts web site and see.  ALSO while in there the balancer nuts should be tightened. You need the manual for torque specs and the correct way of doing things.  ANother thing. Get a magnetic drain plug because loose bolts = metal bits in the engine.

[Lucky]

also, pull the right switch pod apart & clean or file the contacts LIGHTLY.

[Kenny]

 Hi William,
       I recently had a similar problem with my 83 although it was intermittent and one of the problems was with the clutch lever switch and the other was with the side stand relay.  I bypassed both these and it started right up. Ensure your side stand is up when you are starting and have the battery fully charged. Just a few more items you can check.
                      Good luck   Ken S. ;)

[inanecathode]

That clunk is one of the cylinders firing backwards. It happens in every engine, its just with a V-twin (or a big single if you've ever had the pleasure of having your knee launched into your face with the kick starter) the other cylinders cant push it through the compression cycle, so it gets almost to the other side of the compression/ignition stroke but not enough, and fires reverse, hammering on the clutch/starter producing that clunk sound :)

[williamruck]

also, pull the right switch pod apart & clean or file the contacts LIGHTLY.

I took apart the switch pod the other day and cleaned everything off although it looked clean when I took it apart.

I recently had a similar problem with my 83 although it was intermittent and one of the problems was with the clutch lever switch and the other was with the side stand relay

Well, the neutral light is on so the side-stand relay really isn't an issue, but I will try and check out the clutch lever relay.

[williamruck]

I was just reading through the Haynes manual I have and I am wondering if this might be a bad solenoid. I am going to go check it later today any thoughts?

[acee125]

Just a shot in the dark but...make sure that your idle screw is turned in enough. I just got my bike running and that was the problem. It would sputter and give a few puffs every now and then but never stay running.

Try this, take your plugs out and let the cylinders air out for a half hour to an hour. Then put the plugs in and give it full choke. After that hold the throttle open ever so slightly...like barely at all. See if she fires off. I did that and my fired right up. I adjusted the idle screw and now she purrs like a kitten. Or just turn your idle screw up from the start and give it a whirl.

[Night Vision]

Well, the neutral light is on so the side-stand relay really isn't an issue, but I will try and check out the clutch lever relay.

the neutral light works off the neutral sensor switch located behind the left footpeg and is separate and independent from the sidestand relay.

[kwells]

I would suspect the Kill switch(check Ignition fuse first).  When taken apart(lots of pieces) you can jump the kill switch to see if u get spark.  Most likely it is corroded.

[williamruck]

I am pretty sure I have found the issue: As I was looking through the manual it suggested checking the circuit cut-off relay. I did and, with the use if an ohm meter, found it had no continuity. I am going to pick up a new one today and see if that does it.