Bike does not start... troubleshooting - one step at a time

[Enzo]

I am just starting to go through the carburetor on the Vision I bought a few months back.
My hope is that some time between the middle and the end of June I will have the bike running.  After all I am just learning to ride a motorbike.

The previous owner had the carburetor cleaned at a local Yamaha dealer last year, but the bike would not start except with ether and an electrical boost.  So I figure I will need to go through the electrical; however, I started with the carburetor since fuel was spilling out theoverflow when it did run after the carb cleaning.  From what I have read on this site I figure the floats may not be set properly, so the fuel level in the bowls is too high.

I checked the main jets in the carb are 122.5 and 127.5 - good.  What was not good is that they were switched around from the way they are supposed to be - so the 122.5 was in the rear carburetor.  Simple fix. ( But I think I will stay away from that Yamaha dealership except to get a few parts.) The bike has an aftermarket exhaust - Mac.  Should the main jets be changed to different sizes?

I could feel grooves on the float bowl needle valves.  So they will be replaced.

The carb was dry when I took it apart, since it has been sitting on my bench for a month.  I am having a tough time trying to pull the needle valve seat out of its bore. Is it safe to spray WD40 to try to lubricate the rubber o-ring?

I screwed the pilot jet plug out and discovered...(drumroll please)....I need a skinnier screw driver to get the pilot jet out. (sigh)

[Jimustanguitar]

I wrapped the tips of some needle nose pliers with lots of masking tape (just shy of not being able to fit anymore) and easily pulled out my valve seats without marring them. Grab one sidewall, don't put the pliers across both sides of the seat because you might risk crushing the seat into an oval.

If you need lube to pull them out, I would recommend just using a few drops of gasoline. I'm not sure of WD40's gas solubility, so I can't say whether or not it would be a useable chemical for this purpose. It probably doesn't matter if you're going to clean them really well with a solvent after you get things apart. I'm guessing that your overflow problem is mainly related to worn needles, but definitely do check your float levels too. They affect a bit more than just the "to overflow or not to overflow" situation.

Definitely get the right screwdriver, it's easier than you think to strip a brass jet. Extracting them isn't much fun, although it is easier than some other extractions because they're center-drilled from the factory :)

You're in the right place for tech help, lots of guys here have owned several Visions and know all the little nuances. I'm relatively new to this bike too and feel like I learn something every day. It's a nice community too, I'm constantly amazed by how eager other members are to help you. The forum is one of a kind.

Good luck!

Jim

[QBS]

To get a V to start you need a good, well charged, battery, and an oil free starter motor with good brushes.  If the battery voltage drops to 10.5 vdc when cranking, the bike won't start because the TCI system needs at least that much to operate and fire the plugs.  Never under estimate the V's demand for strong voltage to operate happily. These are the first things that you need to verify and make right.  From there you go to the fuel system.

FYI: The charging system can be non existent, but if the battery is fully charged and all other systems are right, the V will start and run well...until the battery goes flat.

[Tiger]

The bike has an aftermarket exhaust - Mac.  Should the main jets be changed to different sizes?

No, you don't need too... 8)

        8) ...... TIGER ....... 8)

[Lucky]

yes you can use wd-40 or any spray lube to get the seat out. even a drop of motor oil on your finger.  won't hurt anything.

[Cdnlouie]

Soak everything with penetrant! Always use the proper fitting screwdriver  :o.  The most difficult jet to remove is the one in the bottom of the float bowl, that requires a very narrow and properly fitting flat blade screwdriver (no slack). Put lots of penetrant in the area for a few days and then pray when you go to remove it, and do not let the screwdriver strip this very delicate jet. If you strip this jet then you may well ruin your carburetor.

They will pretty much all come out, but only for the person who has the right tool and knows what he is up against here.  If it does not easily break free, then you can even put a bit heat inside the bowl on the middle column that goes between the floats (a propane torch - caution no combustible fuel or penetrant in the bowl).  Heating and cooling helps breaks the oxidation holding the jet.

You will need to replace all your rubber o-rings (needle & seats & mixture screw).  I have these readily available if you need them.

[QBS]

A Note to All:  When reinstalling jets always keep in mind who, in all likelyhood, will be removing that jet the next time it needs to come out.  That person will probably be you.  Look out for Number One and do not install the jet with killer tightness. A gentle snugness is all that's required.  The snap of a jet breaking loose with just the minimum of grunt and anxiety is an extremely rewarding event.

[Rick G]

I modified several screw drivers to fit  the various jets , screws on the XZ carbs . I have had one carb where the pilot jet refused to come out , no matter what I did.

[Enzo]

Thanks for the help guys.

I expect that I will be developing my patience further and getting to know this bike very well by the time I get it on the road.

The battery is only a year old, and takes a charge.  I did not check the voltage during cranking, but I was reminded by the comment that the engine will crank over for a few attempts, and then at some point pressing the start button again will result in no cranking at all.  I just figured that was the battery running down, but could it also be the starting motor filled with oil causing a larger voltage drop between the brushes and the armature contacts? I will add that to my checklist.

Of course getting drum brake tension rod shoulder-bolts replaced before I ride it is also on my "to do" list.  I am getting too old to take up pole-vaulting too.

Vince

[QBS]

The starter motor ...must...be in excellent operating condition.

This means: Good, non oil soaked, brushes
                 A spring lip design oil seal
                 Internal cleanliness and oil free condition throughout

Anything less will only produce frustration and confusion.  Once a V starter motor is properly sorted it will provide years of dependable service with zero maintenance required.  The oil seal upgrade is permanent.  Brushes should be considered a long lived consumable item.

[Enzo]

Like they say it's not the fall that hurts...
it's the sudden stop at the end of the fall.

[fret not]

Refurbishing the starter has been discussed before but I haven't found the thread(s).  I have 2 thrust washers at one end of the armature and none at the other, and it seems to me someone said there should be thrust washers at both ends.  Mine doesn't turn easily in spite of new bushings etc.

[Rick G]

Your starter may be out of time.

[fret not]

My starter is out of timeWARP.  Still trying to get back to 1982.

[Rick G]

Seriously , Mike  if its been apart and reassembled incorrectly, it will turn very stiffly

[fret not]

What sort of grease/lube is recommended for the planetary gears?  Wheel bearing grease seems a bit stiff.

[Rick G]

chissis grease or white lithium grease.

[fret not]

Thanks Rick.  And I'm glad you are healing up and feeling better.

[Enzo]

The needle valves did not look that bad.  I was about to check/set the float levels when I had another look at the carbs and noticed the following difference in the float bowls:



and



Has anyone else run into this issue of missing fuel passage caps?  I figure that explains the fuel overflow problem.  Any recommendations on how to reseal the passage?
I am thinking that a mesh and epoxy plug may work.

Also, another newbie question - Where is the emulsion tube located?

By the way, I have yet to use the air nozzle on the carbs; so I know I did not blow it off.

Vince

[Rick G]

Once you take the old gasket off, you will see the emulsion tube.