Thermostat Replacement on an S1

[Ohendo]

For Christmas this year I bought myself a shiny new thermostat (part # 5SL-12410-00-00) for about $20 on Ron Ayers.
I was convinced mine was stuck open, since I've been riding in the cold lately and it takes forever to get her warmed up, and fuel mileage has definitely taken a hit. In fact, I'd dip back into "warmup mode" (one temperature bar flashing on my '05) during riding. After pulling the old one, I'm convinced it was NOT stuck open. Oh well, new thermostat anyway.

The service manual directs you to remove the air filter case, all coolant, and throttle body assemblies, but I managed to make the swap without doing anything but lifting the tank.
I did lose some coolant, not much. Easily absorbed with a towel. I loosened the hose clamp and pulled the hose at the radiator, not right at the thermostat housing, and was able to direct it into a pan and catch a bit of fluid.

With the tank up, a 10mm socket with a 8" extension gets it done. You can feed it down through from above.


Old thermostat out...looks to be seated and in pretty good shape. Not "stuck open", as I had thought.


New thermostat in hand, appears identical to the removed part:



Completed the reassembly, buttoned it all back up, topped off my radiator with fresh 50/50 mix and started it up. Temps were about 40F.
Still seemed to take awhile to warm up at idle, went for a short ride and the same symptoms existed (never really warmed up, max two bars on the temp scale).
I've concluded it's normal, but would appreciate any feedback from cold weather riders.

Merry Christmas to all those that celebrate it!

 

[TownsendsFJR1300]

And Merry Christmas to you!

Per the S1 owners manual, (page 3-3), if temp light is flashing, the temp is still cold .

Once stopped flashing, coolant temp is 140F

The manual doesn't mention anything else.

I read it as long is it isn't flashing, your at at least 140F and good.

I would point out out that although the coolant temp may be to temp, BUT the engine oil temp may NOT.
I feel the clutch cover or stator cover to see hot the ENGINE itself is BEFORE I'll run the rev's higher
(all temps to operating temps.)

If you need an owners manual(PDF), PM me with the year bike.

 

[Ohendo]

Thanks, I appreciate it. I have the owners manual as well as the service manual.

I'm not too concerned anymore, just assumed t-stat was wide open due to the length of time required to get above 140.
Have had this happen before in a car, and besides the poor fuel mileage and low engine temp indication, another symptom would be no heat from the vents. Thought it was an easy diagnosis of a stuck t-stat.



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[TownsendsFJR1300]

Something easy enough to try, try blocking off part of the radiator with say card board.

Limit some of that super cold air, get the temps up a bit without over heating, (just like the 18 wheelers)...

Just watch your temps.

 

[Fawlty]

I think stuck thermostats are quite rare these days, compared to years ago. As for operating temperature, normal for me is two or three bars, this time of year two and in the summer three. Having said that, the winters here in southern Spain are obviously mild, no frost, ice, snow etc. and the summers hot.

Peace and goodwill to all.:thumbup:

 

[FinalImpact]

S2 seems to be about the same but it reports the temp once over 110°F or so. T-stat is set to lift off seat and begin opening at ~164F. On days of 55F ambient temps or lower, the engine temps hover right at the T-stats opening value of 164.

This seems bad for engine life and oil life but they designed it that way. I looked for an oem part that had a 185°F opening but didnt find one.
Like Scott mentions, block off half or more and let it use the fan if your daily ambient wont crest 60F.

Also, if opened up for sustained periods it never rises but maybe 10° over opening value on those cool days. But I'd guess if I blocked 1/2 the radiator AND sat in traffic it would likely overheat even with the fan on. So, if you also encounter long idle times, don't block the radiator or start small like a 1/3 or less.
No clue why Yamers picked such a low value.

 

[Ohendo]

Thanks for the replies, gents. That's a great idea that I was actually mulling over recently. I'll block half the radiator with cardboard and see what happens.


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[TownsendsFJR1300]

S2 seems to be about the same but it reports the temp once over 110°F or so. T-stat is set to lift off seat and begin opening at ~164F. On days of 55F ambient temps or lower, the engine temps hover right at the T-stats opening value of 164.

This seems bad for engine life and oil life but they designed it that way. I looked for an oem part that had a 185°F opening but didnt find one.
Like Scott mentions, block off half or more and let it use the fan if your daily ambient wont crest 60F.

Also, if opened up for sustained periods it never rises but maybe 10° over opening value on those cool days. But I'd guess if I blocked 1/2 the radiator AND sat in traffic it would likely overheat even with the fan on. So, if you also encounter long idle times, don't block the radiator or start small like a 1/3 or less.
No clue why Yamers picked such a low value.

Obviously our S2's have digits.

So far, the coldest it's been down here is the low 50's(F).

If I don't get stuck in traffic, constant speed @ say 50 MPH, it'll take a long time to creep to its normal 172.
It'd stay roughly high 150-mid 160s F.

Now once to 172, it really won't go down anymore (in city, 50 and less MPH) traffic.(and it warms up quickly during the day even now)

 

[gnyce]

The other day, riding home a bit late (and thus caught more stop-n-go traffic), it was pretty chilly.. just below 40 deg. F I would say. I guess I thought the ambient wind-temp would keep the engine cooler, but without decent airflow, before too long the fan kicked on. Found that somewhat ironic in the beginning of winter, but upon reflection that makes sense.

 

[FinalImpact]

I live near a gorge where the wind blows non-stop at times with 20 to 30mph sustained and gusts of 60. Riding direct into the wind on a 35°F day and temps were 135.
Coming back with the wind an average travel speed of 45, the bike was at 195° as wind and bike were basically the same speed so airflow is a huge factor.

Thus I'm pretty certain it would overheat if 1/2 the core were blocked and idle for too long. I guess we need mini shudder that opens and closes. My old air cooled Corvair used a liquid filled billows to open and close shudders to maintain temps - we need a servo controller to open when bike is stationary.

 

[SandyN]

I had the same problem with my S1. The temp bar will flash on really cold mornings and when riding in cold rain conditions. So I pulled the thermostat, also without removing all and sundry and tested it. It did not open under hot tap water and opened under boiling water from the kettle. So I put it back.
I also came to the conclusion that this is normal and that after 20 kilometres the oil is warm and that all the engine parts have warmed up to working tolerances.
It is also normal for the fuel consumption to increase in winter and as a result of the richer mixtures for the engine to vibrate a whole lot less.

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[TownsendsFJR1300]

Just to confirm the above...

Yesterday, we got a "cold front" come thru here in SW Florida.

I took a ride at about 8:00A when it was about 40F (for about 5 miles).

After stopping at a light, my coolant temp went close to normal, about 168F (normal is 172F).
Once moving at 45MPH, my gauge dropped to about 150F that quick....

Point being, the OP's temps are perfectly normal (as mine performed the same-just with #'s).

Now, once the sun came up a bit, it was closer to the mid 60's and the temp swing wasn't nearly
as much as before. ( Nice ride home later!!! )

IF I rode in those CONSTANT, cold temps regularly, I would try blocking part of the radiator to keep
them a bit steadier and warmer...

 

[Ohendo]

That's good info right there! Thanks for confirming normal cold weather operation of the cooling system.
I haven't gotten around to blocking my rad yet, it's just been a combination of either too wet or too cold to ride here (7 deg F this morning, yipes!). When it gets back to more reasonable temps I'll do it and report back. Wednesday supposed to be 40-45.

Thanks again.

 

[TownsendsFJR1300]

BTW, it was a LONG 5 MILES .....

(It's 60F right now and sunny, not bad for riding/playing outside.)


Not like this:

http://newsandbusiness.rogersdigita...0/13639244001_5238239279001_5238231028001.mp4