Carb/Pump issues and other misc questions

[arthurdent510]

Ok, so I picked my Vision up this morning and started digging into it.  It looks like hasn't been titled since '95 and only has 10k miles on it.  And being an Arizona bike, there's no rust on it  :D  I was able to get the bike to fire by pouring some gas down the carb, so I know all the electronics are good.  But I tried to hook a fuel line up to the carb and it won't start...  I know the carbs are horribly out of sync, but I'm not sure if it's actually pumping gas or not.  I had the fuel line off (there was an inline filter that i disconnected) and when I turned it over it spat fuel back up the feed line, which kinda confused me...  should it be doing that?  I do plan on pulling the carbs apart and cleaning them...

A few other things that I ran into...  the choke cable is just a hare too long, and Yamaha doesn't sell them for the vision anymore.  It looks like a previous owner tried to replace it with a 3rd party one that wasn't the right length.  Is there a source for a cable that is the right length?  I also need the 2 rubber elbows that go between the cylinder and carb.  Any good sources besides the dealer?  Really don't want to have to pay $80 a pop for those...

Anyhow, on to the pictures!

http://www.public.asu.edu/~dmhurt/vision/DSC00390.jpg
http://www.public.asu.edu/~dmhurt/vision/DSC00392.jpg
http://www.public.asu.edu/~dmhurt/vision/DSC00393.jpg

[Night Vision]

not sure why the carbs spit back at 'ya... but they won't do that after you clean them  ;)

[Rick G]

If you send me your cable, I can shorten it a bit and install a new end . It will only cost you shipping both ways.

[h2olawyer]

As for the carb boots (intake manifolds), as far as I know, Yamaha is the only source.  However, try coating them with some liquid electrical tape before you spend the big bucks.  Often, these are heavily weather checked, but still solid inside.  They can also be fixed by gluing pieces of a bicycle innertube over them.

H₂O

[YellowJacket!]

The intake boots - the ones between the carbs and the intake manifold are still available new from some of the other sources.  I got a set a couple years ago for 45.00 each....can't remember which source tohoug but it was not directly from Yamaha but they were genuine OEM.  SOmeone just posted a couple days ago that they got some too.

But like H2O saild, the liquid electrical tape is a worthy fix....and much less expensive, as well.

David

[arthurdent510]

Hmm, ok, I think one of the intake boots was cracked all the way through, but I'll see what I can do.  Probably won't be till the weekend before I get to work on it some more, so we'll have to see what happens.

Rick, I think I'll take you up on that offer.  pm incoming....

[arthurdent510]

Ok, looking at doing some work on the intake boots tonight... what's the best way to clean them off that won't destroy the rubber any further?  Something like rubbing alcohol?  Or just water?

[Night Vision]

I wash my delicates with Dawn dish soap and water.... "Dawn cuts the grease"

[h2olawyer]

I'll second the Dawn & water 'solution'.  Gentle yet cleans grease well.

H₂O

[arthurdent510]

Cool, thanks guys!  All clean now and starting to see how well they'll patch up... 

[arthurdent510]

Ok, on to the next question...

One of my mirrors is broken.  It looks like it's just on there with double sided sticky tape, so I was just going to cut a replacement myself.  However, I wasn't sure if there was supposed to be a counter weight in there as well, or where it was supposed to be?  I'm assuming that I have stock mirrors, but please correct me if I'm wrong....  I don't have a great shot of the mirror, but you can catch a view of it here...  http://www.public.asu.edu/~dmhurt/vision/DSC00392.jpg

[h2olawyer]

Actually, those are aftermarket mirrors.  You should have no problems with cutting a replacement glass, but a set of new replacements identical to those is probably about $30.  The original type are still available from Yamaha & amazingly, not a lot more $$ than aftermarket units.  From what I've seen, the Yamaha mirrors are better quality than the aftermarket ones.

Just a little extra info to help you 'reflect' on your course of action to repair or replace.   :D

H₂O

[Night Vision]

agreed... the optics of the OEM mirrors give a much clearer view.....of your elbow ;)

I'd like to take some "good" OEM mirrors and bend them down at the angle point... but I've never had a spare set of good OEM mirrors to try that.

those after market mirrors you have are probably made by Emco... I've found them locally and afar for $10-$15 a pair.. if you do get another set of aftermarket mirrors.... make sure they are for YAMAHA... (they have opposite threads on the pair... so when the bike falls over... they spin loose  ::) theoretically speaking)

[Rick G]

I have a box full of mixed manufacture '82 mirrors , 5.00 pluss shipping.

[arthurdent510]

Latest update  ;D

http://www.youtube.com/watch?v=arBlgLRzq8k

So it runs, but we have to hold down full choke otherwise it dies.  It also seems that only the front carb is being hit by the accelerator pump at this point.  Looking at it a little closer it seems a previous owner re-soldered it back on and did a sloppy job, so I'm thinking that they may have closed the tube off... so I have to pull that apart. and resolder it. 

A question though about needing to hold the choke on;  it this typical till the engine gets warmed up for a bit?  Or does it sound like I have other issues?  And second question, will the accelerator pump always engage?  So no matter what the engine speed, if I hit the throttle, will it activate?  Thanks for the help everyone!  :)

[Brian Moffet]

A question though about needing to hold the choke on;  it this typical till the engine gets warmed up for a bit?  Or does it sound like I have other issues?  And second question, will the accelerator pump always engage?  So no matter what the engine speed, if I hit the throttle, will it activate?  Thanks for the help everyone!  :)

I need to keep my choke on until the temp gauge needle moves.  After that it can idle fine, a little rough at first, but it smooths out as the bike gets warmer.  (Side note, my bike idles at 1000 RPM, which is lower than most, it seems to love it there.)  If you hit the throttle, the accelerator pump should pump in some additional fuel.  It is more pronounced (and if you look at the mechanics, you'll see why) when you're going from idle to full throttle than when you're going from 1/2 throttle to full throttle.

Brian

[arthurdent510]

hmm, ok...  we had the temp gauge up some but it would die as soon as we left off the choke.  Makes me think that it was too lean?  low throttle settings were both at 4 turns out.  Both carbs were getting fuel, but only the front was being hit by the accelerator pump.  The spark plugs are old... but both cylinders and exhaust were hot, so it looks like both were firing.  The local auto shop has the right ngk's, so I'm going to go pick up a new set tonight to see if that helps any...

[Brian Moffet]

Probably running lean.  Before you check jets, pilots, stuff like that check and see if you have an intake leak due to the YICS or the intake manifolds.  Once you're sure you don't then do the normal tuning.  Otherwise the leaks will drive you batty.

Brian

[arthurdent510]

Is it worth putting any liquid gasket or something along the bottom of the intake boots?  Not sure how well 20 year old rubber will seal...  I was looking at capping of the yics tubes anyways, I had a feeling that it may be part of the issue.  Just need to go out and find some caps...

[h2olawyer]

We may have skipped over it, but it is highly recommended to cap off the YICS when first diagnosing carb related problems and getting them tuned properly.  Then add in the YICS (if you want to).  The YICS system, though simple, can add a ton of extra headaches, making it nearly impossible to get the bike to run at first.  Once you know it runs well without the YICS, then you can go about checking the YICS box & hoses, making sure they don't leak anyplace, then installing them - which will also require some minor tweaks to the tuning.

If the carb boots haven't been removed, they should be still sealing well.  You can use the (spray) carb cleaner or starting fluid, spraying either in small amounts next to suspected leaks.  Listen for a change in idle (carb cleaner will lower idle - starting fluid will raise it).  There are gaskets between the boots & heads.  Still available from Yamaha and price isn't too bad for a dealer part.

H₂O