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Bike runs cold


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Hello All,

Like most of you our bikes run cold under 75F ambient. In winter i get 4-5 mpg less than summer time. So experimented around last winter with blocking off the radiator as the t-stat checked out good and 3 yamaha dealers blew me off. A 4.5in tall plate does the trick to get the bike up to the 175F mark for the better mpg. Bike has 89K miles, ridden daily on the freeways splitting lanes in Southern California. 

I split some vacuum tubing and glued it around the metal plate and added some foam tape to the back to protect the radiator and hold it in place with HD zipties.

Hope this helps anybody that is interested.

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1 hour ago, kilo3 said:

I do better with pictures as I'm strong like bull, but smart like hammer.

I don't have any photos but its essentially using something (metal plate, piece of cardboard etc.) to block a portion of the radiator.  About 4" tall and 15" wide to block the bottom half, leaving only half of the surface area exposed to cold airflow.

***2015 Candy Red FJ-09***

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LOL

You're complaining about Left Coast winter getting down under 75!

High tomorrow here will be 25...

If it gets up to 39 and it's sunny, I'll get out Sunday. 

I have a purpose made quilted vinyl rad blanket I prolly bought in 83 that has eyelets to zip tie it in front of the rad guard.  Maybe I'll put it on.

I run Shell Rotella T6 5W40 full syn rear round which flows better in cold weather, and is still 40 in the summer. 

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Yeah, this "under 75f" thing sounds wrong.  Around my part of CA a 75f high is typical, but more typical is highs around 55 and 60.  I ride this Tracer all the time in those temps, and sometimes a bit cooler, but not often.  My engine temps as reported by the bike will def stay down towards the 177 degree mark, only rising during periods of stop and go.  In hotter wx, the bike will heat up into the 180s and 190s, sometimes during stop and go getting towards 220 and the fans come on.  But I have never seen anything lower than 177.  I assume the bike is reporting accurately.

I have had overcooling bikes before.  Notably a 79 Gold Wing that I had to tie cardboard onto the rad during cold wx in Texas, just to keep the engine up into normal range.  It wasn't a great solution, because if I got into stop and go with the cardboard shield in place it would over heat quickly.  This was a cheap solution, would have been better for me to find out why it was overcooling.  None of these modern motors should overcool in such mild temperature.  Probably a stuck open thermostat.  

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It appears no section in the service manual about testing the thermostat..... if it's a 160F-185F typical thermostat, then it starts to open at 160 and fully open at 185... you may see fluctuations when the coolant temperature at the thermostat reaches 160 or above as the thermostat cycles.  The temperature readings are taken from the coolant temp sensor on the cylinder head, and with advent of digital readouts, you're going to see more fluctuations than we did in the analog days.

Edited by RaYzerman
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2and3cylinder, I was never complaining about myself being cold. The post is about the bike engine running cold below 75F at freeway speeds which in my area is a round 80mph. The bike not going into closed loop costs me about 4-5 mpg when not getting to 175F.

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