Operating Temperature Change

OK, I searched the forums and there seemed to be a disjointed but common number of things this could be...So I've decided to post new:

It's been between 62 and 95 the past week (diurnal swing) with varying humidity. Since Monday, and for no good reason I can think of (last maintenence was the rear break pads 4 weeks ago), it's be a bugger to get the bike to warm up.

Typically, I crank up the bike in the morning and go about installing my earplugs, putting on my do-rag, helmet, gloves, etc. and within 1 minute (at rest) we are at 95�F coolant temp.  Within 3 minutes of that (easy throttle, below 4k RPM) we are at 150�F)

Since Monday, the bike simply won't break the 150�F mark for about 8 minutes.

I jacked the durn thing uphill at 30 MPH in 1st gear for nearly 20 seconds, and for the next 2 minutes couldn't even get the bike past 185�F!! which is an absolute rarity.

Is my wax unit/temperature sensor going bad? It wouldn't surprise me, but:
A. how can I diagnose with more certainty what the problem is?
B. Beside the above, what else could it be?

2006 VFR, 1.5 years old, 10,000 miles, regular oil changes, original coolant, daily driver/rider, original AIR filter.

It's worth noting that it runs rough at idle upon startup, but is holding nearly 1200k. The engine vibrates more than is has in the past, especially between idle and 8,000 RPM. It's just chunky, like a V-twin, almost. I'm frustrated.

Thanks for the help :-)

Hmmm...  Thermostat stuck open, eh?

In the IE, my routine is similar.  Start. Gear Up.  100F in the garage.  150+F in two miles.

Got a warranty?  That thermostat is a bizatch to get to...

VFR thermostats have a tendancy to jacknife in the carrier and stick open.

I cant believe there are so many thermo failures, I dumped that honda coolant out at 2000 miles for mix with anything prestone and distilled water.


At 22,000 mile no issue yet

Sounds like thermo., too me.

Definitely the thermostat.  I just had the same problem this past winter with my '98 M3 -- never got up to full temp, took forever to get slightly warm, ran rough, and ate lots of gas.  When it runs cold, the ECM provides extra fuel, and I lost some serious gas mileage.  Replaced the thermostat and now it's smooth as silk, warms right up, and gets great mileage.  If I was a betting man, I'd say your thermostat is shot.

[image: View Post]toro1, on Jul 12 2007, 05:26 AM, said:

I'd say your thermostat is shot.This is pretty much what I am assuming it would be...does anybody have ideas for other things it might be?

Is the replacement just slooooow due to dismantling or actually mechanically highly complex?

[image: View Post]sirimiri, on Jul 12 2007, 09:36 AM, said:

[image: View Post]toro1, on Jul 12 2007, 05:26 AM, said:

I'd say your thermostat is shot.This is pretty much what I am assuming it would be...does anybody have ideas for other things it might be?

Is the replacement just slooooow due to dismantling or actually mechanically highly complex?


Yeah,  set it to outside temp and forget about it! :thumbsup:

When/if it ever gets where it won't warn up enough for the Vtec to kick in, replace it!

Yeah, thermostat.  You may not have had reason to do it before, but as it's warming up touch the top of either of the radiators... by 130 or 140 they shouldn't be hot.

Also, I went through the Napa thermostat book last weekend and they don't have any exact replacements.  There are a few that are close, but too long/short/not offset.  The 115 is the same diameter but doesn't have the 'protrusion' on the other end and isn't offset, so I don't know if it will work or not.

[image: View Post]Baileyrock, on Jul 12 2007, 09:36 AM, said:

Yeah,  set it to outside temp and forget about it! :thumbsup:
When/if it ever gets where it won't warn up enough for the Vtec to kick in, replace it! Yeah, that might be the point.  I have an extended warranty but would have to prove that something is amiss.  Non-VTEC threshold would certainly qualify, IMHO.

But, here's my nooblet question: if a 1.5 year old bike ends up with a dorked thermostat, won't it simply happen again in another 1.5 years? Or is it like those random hot peppers, eat 5, no adverse effect....eat the 6th and end up on all fours, crying on the floor?