Cooling the Desert V

[jefferson]

If you know the cooling system was neglected I would get the radiator boiled out. There can be crud in those tubes that you can't see. Even though you flushed it with clean water and it ran clear doesn't mean all the tubes are passing water.

Jeff

[sunburnedaz]

The rad is not the problem as it was boiled at when I rebuilt the bike 2 years ago and it still ran this hot then. I have run several batches of cleaner though the whole system over the years. The passages where the cleaning agents were able to circulate are clean as can be. The tubes insides were clean, the impellor housing is clean, the thermosat was clean exept for a some gunk around the gasket, the hoses are clean and the rad is clean. Its the areas that the coolant seeped past the o rings is where there is pitting an corrosion problems are. Areas like just on the other side of the o-rings of the tubes had build up that locked the tubes and O rings in place, the thermostat housing was locked in place with that gunk but the passage way was clean.

[supervision]

 Visionmiester, was just telling me a few days ago, about his bike ran hot, and the terminals at the sender unit on the T were the problem, he cleaned them,and the gauge showed cooler.  One more thing, on my bike if I put the catch bottle above the low mark when cold, it sometimes will puke more, than their is room for in the bottle, and it will go on the ground.   Also you  have to have a clean cap, so it can puke to the bottle, and recover to the bottle.  Buy a thermostat, at a parts house, and make sure it is in forward, assembled  correct.

[admin]

you'll get it,  I've no doubt, you're on the right track.

now this rear shock thing sounds interesting, I've been eyeing what I think is that
same model...   98-99 honda cbr600.  it looks really close.
one issue is the travel tho' it has about an inch more travel so you might want
to add a spacer to the cushion.  I was thinking maybe double up on the bushing
might be all it needs to keep the tire from bottoming out on the fender, that
probably wouldn't be pleasant.

  I'd be curious on how you make out on that.


  I know you said the waterpump impeller looked ok, so that's good news, one thing to look at
  while it's apart is if the aluminum is cavitated behind the impeller
  then you could potentially have a flow problem, it should be fairly obvious,
  if not, then a hose into a bucket should answer that pretty quick.

good luck !

I won't be able to test this week as I am attempting to retro-fit the rear shock from a Honda CBR600F4 to the bike and replacing the sight glass on the MC. Shock looks to be about 12" to 12 1/4" inches long eye to eye instead of 12 3/8" that the original 82 unit is. But it looks like I can make it fit with only some clearancing to the bike and pressing out the 10x24x20mm needle bearing and 10x22x28mm bushing and replacing them with 12x24x23mm and 12x22x16mm needle bearings.

[sunburnedaz]

Good thought on the area behind the pump, I will get my gun bore light to see what I can see in that area.

Gonna clean the terminal connection next. One thing at a time as I hate changing 5 things and not knowing what fixed it. I can live with changing out the coolant and the T stat at the same time.

Then if that does not fix it then its off to hunt for stray air leaks leaning me out

Then its gonna be flow bench time.

SO far before this summer started I flushed the system with a good cleaner, then flushed with tap water till it came out clear, then added fresh 50/50 coolant/distilled water charge and burped and bled this thing to death and added a new radiator cap. After all that she is doing what she has done in past summers where running down the road she is a needle width off red then when in traffic or sitting with the engine off for a few minutes, like getting gas, she touches the red zone. After we get going again she sometimes cools off a bit but not back to where she was. She has only got into the red one time and that was after a 5 - 10 minute gas stop and we got back moving 80 plus quickly but she would not come down till she got home and cooled off in her home. At no time did she ever boil over or seem like she was at the verge of it. However her idle does change at temperature, if I set the idle when she is hot she will race when she is cooler and if I set it when she is cooler she will almost die when warm.


On to the CBR Shock thing. The eye length is withing a fraction of an inch relaxed. I am going to see how far off when I get the new bearings with the 12mm openings to replace the bearings and bushings with 10mm holes. Both the 98-2000 CBR600F4 and the 2001-2006 CBR600F4i use the shock with the same length and stroke but with different springs rates and valving. I have built a few adapter plates and test stands to do some shock testing to measure actual spring rates and strokes of the 82 shock and the spring rate and stroke of both the CBR600F4 and F4i shocks I have laying around. I literally need to borrow someones free weight set to find out what the spring rates are for the different units. I think the 82 shock might be under sprung for MY weight (250 lbs I am sorry to say) but without measuring the sag of the bike fully geared up I am not sure at this time. I KNOW its under dampened because I see evidence that the 82 shock might be blown out completely at the point as there is a good amount of oil and build up on the far end of the shock.

As for bottoming out I am already bottoming out on the stock spring on squarish bumps like expansion joints or steep sided speedbumps so I need a higher spring rate too keep from bottoming out so if the spring rate is lower than the 82 I will keep looking.

[sunburnedaz]

so this is what I have been talking about the water passages are mostly clean. As main passageways are free of buildup.





its the dead areas like where there is that dead spot on the bottom of the water pump cover that still have some build up in them but nothing that should effect the cooling of the V. And the Rad was boiled clean 2 years ago when she was first put back on the road so that is even cleaner than the this pump cover.

Also anywhere that coolant was able to do any kind of seeping while it sat in my friends garage for several years shows the same kind of glue/gunk/buildup as you can see the area around where the thermostat cover mates up and there was that O-ring seal its full of that glue like gunk.

You can also see it if you zoom in on the upper gasket area of the pump there is some clear evidence of the gasket drying out or letting some kind of seeping happen around it.

[Jimustanguitar]

In response to some of the lean mixture comments. This is true. Running lean makes the engine hotter, and is especially harmful to valve seats. Somewhat related: many "performance chips" for injected cars and bikes do nothing more than just richen the mixture a touch to cool the intake charge.

I second the "check your sending unit" suggestion. If the gauge needle moves based on resistance, corroded connectors, oxidized wiring, loose terminals, etc could all cause inaccurate readings. Have you used an infrared thermometer gun to compare the estimated temps for different needle positions (mentioned above) to actual measurements?

[Rikugun]

There are 2 terms that are similar , but mean different things . Vapor lock is basicly the gas is boiling in the carbs , this does not affect engine temp , the bike just stops running . Air lock is  the term for entrained air in the cooling system , which can impede the flow of coolant and  cause the bike to over heat. This is probably what you had . There is a bleed screw in the water manifold at the top of the  cooling system , under the tank.

When I said vapor lock I was referring to vapor lock.   :D  This only happened when the bike was up to temp and on a hot day - 90 or better. And this was still a factor after changing the coolant and removing any trapped air. A typical scenario would be if I did some highway miles that works the engine hard and then exit and go into town. The first light encountered saw the idle drop until it stalled. Restart would require full choke and/or a throttle twist or two. Once running, it was hard to keep running and exhibited reduced power. I thought perhaps the fuel in the pump body was boiling, not the carbs so much but either way vapor lock seemed a likely culprit.

After some time of moderate speeds these symptoms would be lessened but it never was as happy as on a cool day.  :(  I often wondered how Visions living in Arizona dealt with the heat.  :)  Anyway, sorry to hear it's fighting you but keep after it.

[Rick G]

My Vapor lock problem occurs when the ambient temp is 105- 108  or hotter. At 118 it will stop every time you slow down  and take 1/2 to 3/4 of an hour to recover. The cure was to not ride the bike down to the River in the summer. The problem seems to be acerbated  by the fairing. There is a baffle in front of the carbs , but the fairing seems to trap a lot of heat under the tank.  Don Minor and I kicked around the idea of installing a couple of scoops , made from small vacuum cleaner  attachments and some of that heat riser tubing , used in cars from the stove to the air cleaner snorkel. to provide more air to ventilate the area under the tank.
I  sidestepped the issue by not riding the Vision to the river, when its that hot (no fun anyway) My Suzuki VX800 is totally immune to the phenomenon, It has no fairing and the carbs are 18 inches apart, with the rear one behind the head and the front one up under the tank.. The radiator might be a bit larger too.  Although the Vision never had any issues with over heating , even when the carbs stopped working,

[Rikugun]

It does seem as if the Vision's cooling system is a bit weak. Even if it doesn't "overheat", if it's rendered unable to be ridden, the heat has won! :D I've never ridden in temps like that and don't think I would if given the chance. Doesn't sound fun at all.  :(

Thanks for the heads-up regarding the 83's fairing. I've just finished mounting one I picked up some time ago. I'll have to pay attention to the temp to see if it's more vulnerable now with the fairing on. Do you think it matters if it has the lowers or not? Mine has just the (upper) fairing.

[Rick G]

Please under stand that mine never overheated, never even came close. The heat trapped under the tank , when riding slow or stopped was the problem and this was reflected in the lack of carburation.The air flow, while moving at speed kept the air temp. under the tank under control.  I suspect that removing the lowers would improve the situation , but never tried it.

[Rikugun]

Yes, I understand that according to the gage your's did not overheat.  My remark was more of a was a general comment as many have complained that their Vision runs in the upper range and sometimes near the red in very hot weather.

[Rick G]

Actually, mine used to run very close to the red zone . Water wetter seemed to help quite a bit.