Thermostat Replacement - 6th Gen VFR800 VTEC

I feel for you, I had to do this myself last year. I did not fully remove the throttle bodies from the bike, just sat them up on the frame rails so I could get to that darned thermostat.

 

Yeah, hoping I can just lift it a little and get my little mits in there without disturbing too much... Probably a $500 job at the dealer for a $13 part...

 

It really isn't all that bad! Think of it as taking a few hours to get to know your bike in intimate detail - I mean really, when's the last time you two sat down and just ... talked? She'll appreciate it!

Aside from swapping that IAT connector (very frustrating, but easy to remedy) I will say that I look back on this job fondly. It really makes me miss my VFR days.

If you just take your time, make sure you have the right tools and go gentle with it, it's really not a terribly difficult job. Give it a shot! Good luck!

 

Elegantly simple explanation of why.

 

The 2 most difficult things about the job are the following:

1. Removing the throttle bodies, you can't easily just pull them off. I've found that if you use a screw driver and jam it in the rubber housings it helps loosen up the grip.
2. Reattaching the thermostat to the two rubber hoses, you have to do it at the right angle otherwise it won't go in. I've found that putting some dish soap on the tubing helps slip it in easier.

 

Question. Has anyone tried a inline thermostat. My old 8n ford tractor has a thermostat in the radiator hose. I'm close to 50k and I'm sure my day is coming.

 

Yeah, that was a thankless job...

So many design choices that made it more difficult than it should have been. I had to go out and get a foot-long screwdriver so I could get to the clamps on the Throttle Bodies - there was no other way. The spaghetti mess of wires, hoses, cables, and connectors was a little daunting to disassemble. Got it all out, and back together, only to have to chase down a vacuum hose that I couldn't find the connection for (compounded by a loose end of one that I had removed when I did the flapper). I can partly thank myself for that, and the delay going to the store to get a screwdriver had. My short term memory dumped. Had to print the vacuum schematic from the manual to figure it out.

Got it back together, settled and purged the coolant, and the temperature went back up to 224F with it on the stand, so I shut it down.

Then I realized the fan was not running. I put power on the terminals off the connector - no spinning. Damn. Pulled the fan and harness and was going to swap it out the fan. Pulled the fan from my VTR to cannibalize, and decided to try shorting the ground and the terminal from the Fan Sensor. Voila! The fan spun right up. Next theory was that the Fan Switch (in the radiator) was bad - no parts in town. Boo hoo. Put a little squeeze on the terminal connector, and warmed the bike back up. Whirrrrrrrr!!! Music to my ears - the fan spun up at 220F, and ran it back down to 204F. Success.

So, short story - I spent all day pulling the thermostat, $50 on Engine Ice, tore apart my VTR, and made three trips out to the bike shops. In the end, it appears my super-warm running bike was simply a victim of a bad connection on the Fan Switch. 8 hours later, I discovered the 1 hour solution. Gah...

At least know I know what is NOT going to give me problems for a while... <fingers crossed>. Learned a few things in the process, but would have rather spent the day at the beach...

That was the Long Way Round. Hope someone benefits from my journey. I am glad that i have a new thermostat and some nice fresh Engine Ice though. It does seem to cool down much faster now ...

 

Nothing like taking pics as you dissassemble.

 

The common misconception with the fan switch is that it completes the power circuit, when actually it is completing the ground circuit. It is easy to get caught without a wiring diagram to look at, as it goes against what most folks would consider a normal ciruit to power an accessory.

When it comes to the vacuum lines, I switched all of them to red silicone hoses.....much easier to see when one isn't connected. With all of the black hoses in that area of the bike it is easy to subconciously miss a connection, especially when one is in a hurry.....when they are all red I found that it subconciously grabs your attention when they aren't all connected.....much easier to troubleshoot after major maintenance too.

The stock black hoses will also become brittle and split due to the heat generated in that area, and it will happen quicker than you might think....the silicone provides extra peace of mind.

 

So Rooster, after all that did you need to replace the thermostat? I replaced the one in my VFR and it was jammed open, so at least I had a visual confirmation. I also suspected my VTR1000 of the same thing and swapped that out (a much, much easier job) only to find that it was in perfect order. I did the dipping in boiling water test and it opened right up.

 

Hi there

Just in relation to this step , Is this described in the service manual or did you just find this out from someone ?

Cheers
Martin

 

JUst for comparison and to demonstrate that improvements come with a cost......on gens 1 & 2 the thermostat can be changed in about 5 minutes and requires the removal of only 3 bolts !!!!!

 

Ought to be waterboarding then hanging for the designer of that cluster----.

 

Yep, the old Magnatoids of yore, they were hanging right on the right side of the engine, or it would be the left side depending on your vantage point :lol: Old viffers where the same way. I went through some :bs: doing my gen 3 bikes, I had to re-live the entire chore of pulling off the carburetors because the two water hoses that come off the t-stat, one had a bit of weepage :frusty: Also that t-stat has an orientation that it wants to be situated in the housing, I believe the weep hole in it wants to be facing forward. Its in the manual, I replace the t-stat along with the perishable large o-ring. I do insulator boots as well, sometimes I change the bands too. The bands for the carbs on my bikes at least are easy to access with the mids off and occasionally put one of my may long screwdrivers to them to check overall tightness.

I had some rusty crusy (where did Crusty go anyway?) radiator hose clamps that I replaced. I had some coolant draining from my overflow tank and could not figure it out, I re-tightened the bands but no avail, I ended up pulling off the lower where the water pump was and I noticed a CH of coolant on the foam backing that they used to give on you bikes when they gave you "more" for your money. Anyway, I bought a bunch of new OEM bands installed them and coolant level is happy. I got a coolant issue on my commuter bike right now, (kawasaki) where I am gona over haul the water pump with a mechanical seal, oil control seal and some assorted gaskets. Cheers, Nice original write up on the t-stat replacement on that FI bike, I think that doode sold his VFR and got a VTX13 if my memory serves me correctly.

 

You don't have to pry at the throttle body with anything when you're removing it. Instead you can loop a cargo strap under one corner of the throttle body assembly, then loop the strap over your shoulders, then brace your hands on the frame rails and push. This will easily free even the worst stuck throttle body assembly.

 

I couldn't get my assembly free so I carved out some pry tools from some hard fir I had in the garage. Mine were custom. Agreed, the corners are the place to start.

 

As ridevfr suggests, hoses shrink after years under the clamps, so an annual go-around with a screwdriver on all clamps to tighten up 1/4 or 1/2 turn is best maintenance practice.

 

Very good and well explained process to replace the thermostat
At this point I have my ride stripped down for other service and I think I will replace the thermostat now instead of later, with my luck if I do not replace it now it will act up on the first ride of the summer.
Electrical wiring connections can get switched sometimes and I have questioned which wire goes where many times over the years.
My tip of the day is when you unplug wire connections wrap a piece of masking tape around each end and mark each tape with matching numbers

 

I got nail polish in my tool box for some stuff like that, use white out or correct a type, or what ever they call it these days. I have used zip ties in the past to segregate/designate fuel lines in/out so as not to mix them up. Ice Hunchin :smile: :smow: Barf-ah-Low is cold huh... eace:

 

Don't pry here: