Overheating? Warm fuel running out gas cap...

[VisionSeattle]

Let Vision idle for an hour and found warm gas seeping out and bubbling the paint underneath the cap.  The tank was half full and bike perched on center stand.  The temp gauge was still in the green, and the fan seems to switch on at the proper time.  The coolant looks normal as far as color, just have not checked if the mixture is correct.  Previous owner changed the coolant and the bike seemed to be carefully maintained and has 11k miles.  The only clue I have is a few drops of coolant had exited a hole on the front edge of the side cover just below the water pump housing unit.  Does that hint of a clog that would prevent proper circulation - therefore overheating the gas in the tank? - or perhaps the pump just needs maintenance?  Or is it my gas cap does not vent properly?

[YellowJacket!]

There is a whole lot of heat rising up and heating up your gas tank especially if the bike isn't moving.  After one hour of idling on the centerstand, thats not surprising.  My 82 tank has a heavy rubber(?) insulating pad under it that came from the factory that way.  Over time, the glue breaks down and thos pads either fall off or get pulled off.
Even with the fan running to cool the engine, there is not enough airflow to cool the rest of the bike so your situation sounds understandable.
You may also want to check the vent hole in the gas cap (doubtful though if the bike idled for an hour)

Fianlly, you may want to "burp" your coolant line.  Of the PO refilled the system and didn't burp out the sir bubble then the cooland does not flow adequately.  Since it is not flowing past the temp sensor at the rate it normally would, then it may not be picking up an accurate temp reading.  But, if the fan is coming on and turning off, it could be reading ok.

David

David

[Rikugun]

a few drops of coolant had exited a hole on the front edge of the side cover just below the water pump housing unit

Isn't that the weep hole that lets you know the pump seal is going away?

[QBS]

Haynes says when weep hole weeps change water pump real soon.  Lest oil and water begin to mix.  If fan is coming on properly, the system is probably properly filled.  Read up on these items in Haynes if possible.

[h2olawyer]

I tried (successfully) a Prestone product: "Water Pump Seal Conditioner" when I noticed a drip from the weep hole on my V.  Haven't had one since and that was a long time ago.  I hear older Gold Wings have a bit of an issue with their water pump seals as well.  It was the owner of one who informed me of the seal conditioner.  You just add it to the coolant.  I used about 1/4 of the bottle since thre is so much less coolant than in most cars.

It is difficult to find & I've been unable to find it on their website.  Only suggestion is to search in various auto parts stores.  I found mine @ Checker (Kragen's in many parts of the US).

If you can't find the stuff, then you will need to make the necessary replacement / repairs.

I've changed my coolant twice since I did the 'fix' and switched from Yamacool to Enginge Ice and I still have no weeping from the pump.

H₂O

[Lucky]

There is a plastic air dam that sits between the carbs & the fan, is yours there?

[VisionSeattle]

Lots of good info that I'll use in diagnosis and hopefully make those fixes.  My tank has no signs of any sort of heat barrier applied to underneath the tank...I'll have to do a visual check on if there is a plastic shield between the radiator and tank, I don't recall seeing that.  Also, it probably does not help that my bike has a lower fairing that traps some engine/radiator heat and contributed to the excessive warmth to the gas tank. 

THANKS!

[kiawrench]

visionseattle,
you can make a heat barier for about 10.00 .  go to auto parts store, walmart or the like , and get one of the big reflective silver windshield sun deflectors, . this will be cut down and glued in place under the tank , providing heat deflection (works good in seat rebuild for same thing )

  drain and remove your tank, cut the screen to fit under tank and allow the tank to be mounted, glue in place with 3M spray adhesive . once dry and happy, just remount tank, refill with fuel , and get back to riding.

[jasonm.]

a few drops of coolant had exited a hole on the front edge of the side cover just below the water pump housing unit

Isn't that the weep hole that lets you know the pump seal is going away?

yes...that is the weep hole to tell you ...YOUR SEALS are bad! As far as the gas comming out the cap. The venting must be screwed up in the cap. Catching gas then letting it out when pressure builds. None of the Visions I have had ever did this.

[akvision]

You can go to the local hardware store and purchase silver bubble wrap and glue it under the tank to help it stay cool or just ride it and avoid traffic congestion.   I was going to do this fix.

In Denver, I was riding in slow...traffic a couple of times,  AKVision, (b***h, I loved, who was unfaithful!) was vapor locking, I had to pull over and talk to her sweetly as she cooled down..  inside I was disgusted.

She whispered,  "I just want to go." 8)

[don_vanecek]

The gas tank on a Vision has a lot of surface area to absorb all that heat from the engine running at idle for a long perioud of time. Cooling system for the engine may have kept the engine temps within tolerance but if you weren't moving much or at all (were you in a parade?) that heat is all going up to the U shaped gas tank. I 'm sort of surprized you didn't vapor lock.

Ah, these V's love it out on the open road and moving along. I would be worried running the V say in a parade on a warm day for an extended time, it wouldn't like it.

[Kenny]

  Hi VisionSeattle,
       Welcome to the site.  I'm not sure to what purpose you would be idling your "V" for an hour for,I don't know of any situation I could get into.
   In Europe you get a hefty fine if you are idling for more than 5 min (Pollution).
   A couple of things you can do to help- as akvision mentioned line the underside of your tank ,most hdw stores have a reflective insulation that has a sticky side . You can also Drill your filler throat on the tank,this seems to eliminate most over flows.  In the eighties my 1st vision gobled up a few water pump seals but I have had none go since. I have noticed  the odd drip or two but considerate normal ops.Check the upper plug in the cooling system(fwd of the air cleaner)when your bike is cool & ensure the system had no air in it.
   I have found that I can often change the hot air flow on the road by moving my knees in or out.
                              Having fun yet!! ;)
                                   Cheers Ken S.       

[Tiger]

 :) Hi and welcome to the ROV... 8)

If you need to let your Vision idle... when doing tune ups, maintenance, etc, put a household electric fan in front of the Vision and operate it on the highest setting. This will help disperse the heat quicker and help avoid any damage to your Vision.

With your gas cap removed, look inside and you will see a 'lip'...at the highest and lowest point of this lip drill a 1/8" hole through the edge of the outer lip and through into the gas tank...This will stop volcanic gas eruptions from the tank when hot!!

Unless I know them really well...I very rarely trust what another owner tells me he has, or hasn't done, unless I can 100% verify!! So, empty out and flush the whole cooling system. Refill using a 50/50, 60/40 coolant/water mix. Use a good quality, aluminum friendly product.

           8).......TIGER....... 8)

[QBS]

When adding water, use mineral free distilled water .

[jasonm.]

:) Hi and welcome to the ROV... 8)

If you need to let your Vision idle... when doing tune ups, maintenance, etc, put a household electric fan in front of the Vision and operate it on the highest setting. This will help disperse the heat quicker and help avoid any damage to your Vision.

With your gas cap removed, look inside and you will see a 'lip'...at the highest and lowest point of this lip drill a 1/8" hole through the edge of the outer lip and through into the gas tank...This will stop volcanic gas eruptions from the tank when hot!!

Unless I know them really well...I very rarely trust what another owner tells me he has, or hasn't done, unless I can 100% verify!! So, empty out and flush the whole cooling system. Refill using a 50/50, 60/40 coolant/water mix. Use a good quality, aluminum friendly product.

           8).......TIGER....... 8)

He said his gas issue was when half full. Yes , drill that hole. Just do it in the corrct spot. The higher the better