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Thermostat issue?


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Well I would never argue the wisdom of replacing something that has reached its useful life.  Especially something as important as a Thermostat.  I replaced mine after 10 years of use, even though it wasn't broken.  It required removing the Throttle Body on my 6th gen.  It was a lot of work but not difficult.  But now I don't have to worry about it for a while, as opposed to always wondering when will it fail on me....I prefer being pro-active.  I did the same thing for my Stator two years ago.  Even though it wasn't broken I knew the chances are good it was going to fail after 40k miles.  The old stator came out looking like the lower half was a fully cooked Thanksgiving Turkey!  Replacing that was also a lot of work but it was worth it and I'm especially glad I was pro-active with it.

 

If you suspect something is amiss, inspect it to make sure all is well.  If it makes you feel better to be pro-active about preventative maintenance, more power to you.    I agree with this kind of logic.

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37 minutes ago, Rogue_Biker said:

  The old stator came out looking like the lower half was a fully cooked Thanksgiving Turkey!  

 

 

Next time, read the recipe more carefully, paying special attention to oven temperature and roasting time :goofy:

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On 11/28/2017 at 8:14 PM, Rogue_Biker said:

Well I would never argue the wisdom of replacing something that has reached its useful life.  Especially something as important as a Thermostat.  I replaced mine after 10 years of use, even though it wasn't broken.  It required removing the Throttle Body on my 6th gen.  It was a lot of work but not difficult.  But now I don't have to worry about it for a while, as opposed to always wondering when will it fail on me....I prefer being pro-active.  I did the same thing for my Stator two years ago.  Even though it wasn't broken I knew the chances are good it was going to fail after 40k miles.  The old stator came out looking like the lower half was a fully cooked Thanksgiving Turkey!  Replacing that was also a lot of work but it was worth it and I'm especially glad I was pro-active with it.

 

If you suspect something is amiss, inspect it to make sure all is well.  If it makes you feel better to be pro-active about preventative maintenance, more power to you.    I agree with this kind of logic.

 

Yeah, that's more than fair enough. But the point here is that normal behaviour with this particular breed of bike is being challenged, potentially causing people unnecessarily cost. They LOOK like they run cool, just because the needle runs about an eighth off the bottom marker does not mean it's running cool, at all!

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OP here, what I hope to do tomorrow is do the test suggested by a few here, the start up with a couple of temp probes attached and see what is what.  I am hoping to see a somewhat cool radiator get hot rather all at once as the tstat opens.  I am in the AC business so I have no dirth of temp devices.

 

I will post results

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10 hours ago, bykemike said:

OP here, what I hope to do tomorrow is do the test suggested by a few here, the start up with a couple of temp probes attached and see what is what.  I am hoping to see a somewhat cool radiator get hot rather all at once as the tstat opens.  I am in the AC business so I have no dirth of temp devices.

 

I will post results

 

Cool, will be interesting to see. However, if the thermostat IS broken...it doesn't really prove a thing, these bikes look like they run cool, always have, always will :)

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well, very interesting, I am going to conclude I have an inoperative thermostat.

 

Sitting in my shop I ran it up until the fan came on at 199 deg F. That took more than 15 min.

 

The radiator moved up from 80 deg F to 114 deg F a minute or so after starting, I have a few images here of the degrees and the gauge position. When I am driving I never see the gauge this high, in fact I seldom see it into the scale at all,  except in traffic and the gauge tracks , to some extent, outside air temp.

 

Fan comes on at just over 1/2 way up on the gauge.  I would think this engine would run at least 170 degrees to be happy which would mean I would need to see a just under 1/2 gauge while running no matter what the outside temp is, I mean, that is the job of a tStat, to deny cooling unless it is called for, right?

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That last picture of the temp gauge...is that at 199 deg F?  You're measuring radiator temp?  Or Coolant Temp?

 

The Thermostat will not open until coolant temp reaches about 172 degrees F.  Then it will open up and is fully open around 185-190 deg F.   I would wager that the red zone on your gauge is 230 deg F.  Most liquid cooled, piston engines make the most power at 170-175 deg F.  It produces the lowest emissions at 220 deg F.  My VFR has a digital Coolant Temp reading and on cool days, running normal speeds, the bike maintains 172 deg F.  But on warmer days, lower speeds in 2nd gear, the CT can get as high as 220 before the fan kicks in to bring it down to around 210-215 deg.  

 

Unfortunately, on a carburated bike, you don't have any other way to verify thermostat operation without just taking out the 'stat and testing it.  ON FI bikes, if the 'stat is always open we would notice a much higher fuel consumption because the ECM will be pouring too much fuel in the engine thinking the engine is still cold....because it is.

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I went with method #2.

Pulled the t-stat (30 minutes on a Gen 4) put it in the freezer for an hour and ta-daa, still wide open.  Got one coming from Partszilla.

My bike has been running too cold for maybe 4 years of its life except for the occasional traffic jam.  PO told me "I have never seen the needle come up more than a needle width"

 

BTW, I was reading top of radiator tank temp for ease and continuity but I checked the rear cylinder water jacket and it matched pretty close.

 

Last picture was 183 F, fan came on at 199F, the gauge was just over 1/2, fan shut back off at 190 in just a couple min. 

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Seb,

 

Make us a few of these for a 1" hose :>)

 

https://www.amazon.com/Meziere-WN0071-Inline-Thermostat-Housing/dp/B003NDFEC0/ref=pd_lpo_vtph_263_tr_t_2?_encoding=UTF8&psc=1&refRID=YAXKSYGJFH1N840C8TJH

 

they can go in the upper hose , the lower hose, what ever and you can check /change a t-stat whenever, they seem to only be available in 1.5" and 1.25" hose sizes

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While I have all the big minds here :) :)....I was looking at a set of Samco Hoses for this bike, why not, right? but at over 210 USD I was wondering if anyone knows of an upgrade hose kit a little more economically priced?

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Gotta ask about the Samco hoses...what's the point? You'd be better off sinking that money into suspension components (if you've not done anything already, that is)

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I don't really know, I have my hoses off and they look ok but they are off and the glossy red Samcos are calling my name. I mean I am expecting my glass clutch cover to be here soon, you can see what type guy you are dealing with .  Ohlins or Ohlins like for the rear will happen soon, as well as tires.

 

  I think the deal with this bike is it didn't cost much at all and I really, really like it. I just like dicking around on my bikes. My business needs me to be in or around my shop most of the day and all my bikes and bicycles, tools, Keureg machine, Bose, etc is just steps from me, its a tempting situation.

 

  I'll bet I like it more after the engine warms up !

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LOL!  So the moral of this story is, if in doubt, just replace the damn T-stat.  I kid.  But I would.  10 years is a long lifespan for that and you got your money's worth.

 

Go with OEM black hoses.  If you want dress up items I'd go for powder coated wheels, carbon fiber bits,  cool smoke colored windshield,  etc.

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12 minutes ago, Rogue_Biker said:

LOL!  So the moral of this story is, if in doubt, just replace the damn T-stat.  I kid.  But I would.  10 years is a long lifespan for that and you got your money's worth.

 

Go with OEM black hoses.  If you want dress up items I'd go for powder coated wheels, carbon fiber bits,  cool smoke colored windshield,  etc.

 

 Oh, no doubt I have a new tstat is ordered for next day delivery!

 

Next thing I am looking for is the gen 3 8 spoke rear wheel, there is one on the classifieds right now that is perfect for me but it is always a money thing

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A shameless plug for Partszilla!

 

  23 hours ago I posted a pic of my broken thermostat and the notice I had one ordered with Partszilla, 23 hours later, (about now) the bike is all reassembled  and I am out the door in 30 min for a 50 mile test ride this afternoon.

 

The order came from Partszilla so fast, it is astounding.  The local Honda dealer, who was very nice, was talking many days and twice the price. It is an internet world Charlie Brown.

 

I will update after a days ride as to where my temp needle is running. It would never show hardly anything while moving before

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OEM hoses for older models are already NLA.  Sillycone makes more sense then (though the Chinese sets for the NC30 seem to be cheaper than OEM would be anyway).

 

Ciao,

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Results from a thermostat change:

 

  Good ride, nice weather today 72ish, about 40 miles.

 

  Bike warmed up very quickly, off the choke sooner than usual, it seems to have lost the rich fuel smell at idle, idle much improved. 

 

 I had to turn the idle down at the stop I made at the 25 mile mark, seems to idle better and lower rpm, about 1100 rpm right now, holds the heat a little longer than it did (that would make sense since it is running hotter).  Based on what I have seen and some of the replies to this thread there may be a few stuck t-stats out there.  My temp gauge now goes between the brackets and stays there.

 

Here is where it ran the whole ride:   Based on yesterdays results it appears to be just shy of 182 deg F,

 

 

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48 minutes ago, bykemike said:

Results from a thermostat change:

 

  Good ride, nice weather today 72ish, about 40 miles.

 

  Bike warmed up very quickly, off the choke sooner than usual, it seems to have lost the rich fuel smell at idle, idle much improved. 

 

 

This is what I noticed as well, except for the rich smell at idle but that's another issue.

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I was just rechecking it and there is still a rich smell but very faint vs. not so faint before. Just for a test I was going to block the radiator a bit to raise the temp 10 degrees or so and see if that changes anything.  I am not fixated on this but the bike is much nicer when it warms up and I may push this a little more.

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Most older bikes will smell slightly rich. Mine started smelling even richer after I de-PAIR'd it, no longer burning unburnt fuel leaving the cylinder. I need to get it to a good shop with a dyno and someone experienced with carbs that can help me. I just don't see spending the $500 in setting up an AFR sensor and a Carbtune to be able to do it myself.

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If your bike is carburated, it wouldn't compensate with a richer mixture even if the engine temp is low.  At least not the way I understand it.  Unless you had to keep the choke on to idle smoothly.  

 

Coupedupsubie, if your bike has a stock intake, your factory jetting should be right.  If you just put a "freer flowing air filter" in, and/or a freer-flowing exhaust, then all you have to do is adjust the pilot mixture screw a bit.  I'm sure your carb has these for each cylinder.  You ride the bike until engine temp is up to normal.  Let it idle, adjust the Pilot Mixture screw in (turning it in like a normal screw) until the idle gets erratic, then turning the screw back out slightly until idle smooths.  I believe this is the standard procedure for all carburators.  The only time you would need to change the main jets is when you OPEN up your air box and significantly increase the amount of air entering your engine.

 

 

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yeah I agree, there should be little , if any, effects on the way a carbureted engine runs if it is running cold, the idle may be affected but, with a manual choke,  you would keep the choke on a bit to compensate for that.

  I think what I may be seeing is I was able to reduce my idle speed  (by closing the throttle plates a bit) when I brought the temperature up to where it belonged so maybe by running it with less of a throttle opening I was reducing the fuel introduced to the cylinders.  

 

With the previous engine temperature I had a ragged, hunting idle note and it would average about 1400, when the temp came up the idle would smooth out and get faster.  I noticed a hint of this when the idle would be smoother stuck in traffic with the temp climbing.

 

  This afternoon I turned the adjustment knob under the tank to bring the idle to just over 1000 and it idles there really well. 

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4 hours ago, Rogue_Biker said:

If your bike is carburated, it wouldn't compensate with a richer mixture even if the engine temp is low.  At least not the way I understand it.  Unless you had to keep the choke on to idle smoothly.  

 

Coupedupsubie, if your bike has a stock intake, your factory jetting should be right.  If you just put a "freer flowing air filter" in, and/or a freer-flowing exhaust, then all you have to do is adjust the pilot mixture screw a bit.  I'm sure your carb has these for each cylinder.  You ride the bike until engine temp is up to normal.  Let it idle, adjust the Pilot Mixture screw in (turning it in like a normal screw) until the idle gets erratic, then turning the screw back out slightly until idle smooths.  I believe this is the standard procedure for all carburators.  The only time you would need to change the main jets is when you OPEN up your air box and significantly increase the amount of air entering your engine.

 

 

 

It has a Two Brothers exhaust manifold, well which ever I decide to run for a while as I have a left and right exit. A previous owner installed the exhaust and rejetted it because he didn't like how it ran. I have it running as good as I can for now. I do have a K&N air filter that I haven't put in yet so that may get put in before this summer. The Pilot Mixture Screw setting procedure you described it right, and pretty much standard across all carburetors.  

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On 12/1/2017 at 9:50 PM, bykemike said:

Results from a thermostat change:

 

  Good ride, nice weather today 72ish, about 40 miles.

 

  Bike warmed up very quickly, off the choke sooner than usual, it seems to have lost the rich fuel smell at idle, idle much improved. 

 

 I had to turn the idle down at the stop I made at the 25 mile mark, seems to idle better and lower rpm, about 1100 rpm right now, holds the heat a little longer than it did (that would make sense since it is running hotter).  Based on what I have seen and some of the replies to this thread there may be a few stuck t-stats out there.  My temp gauge now goes between the brackets and stays there.

 

Here is where it ran the whole ride:   Based on yesterdays results it appears to be just shy of 182 deg F,

 

 

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This is precisely where the VFR temp gauge sits when the bike's at normal operating temperature - how much lower was it before?! If you were on the go, making good progress without slowing down or sitting in traffic, it'd drop a bit below that. People ask about this as they assume it should be sat half way...as per any car, van, truck or (potentially) bike they've driven/ridden.

 

So while your thermostat was stuck open, it still doesn't prove anything in terms of this being some kind of common issue...it just shows yours was open. It's normal for these bikes to show a low(ish) temp reading in normal use. In traffic, that thing would bounce above half way and the fan would kick in as normal.

 

However, if people can be bothered and their bike is running odd in some way AND they're spanner capable...there's no harm in whipping it off the RC36-2 and having a look. It's a much more involved process on the 36-1 due to the daft positioning of the housing, as has been stated previously.

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