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If it’s in the low 60s is the cooling system strong enough to keep the engine from getting really hot if it’s just sitting idling? (Did this in the evening so the Sun did not add to the temp.) I thought it was but having second thought about that. After draining the coolant and refilling, I started it up, watched the temp come up to two bars, walked away for about 15 minutes letting it idle and surprised to see the temp gauge was showing one short of all the bars when I came back. (Fans were running.) I assume I caught it before all the bars were showing. Is this normal or do I have a cooling issue?

The cooling system takes 2.75 liters and when filling the radiator, it took 1.9 liters. I assume the rest is in the block. I also added 300 milliliters to the reservoir which put it about an inch above the full mark. After the engine had cooled down overnight the coolant in the reservoir was right at the low mark, I’ll add more coolant to the reservoir. Do these numbers sound right or do I have some air trapped some place?

Sounds pretty usual for a pressurized system. Chances are there was a bubble caught behind the thermostat and it didn't clear until it opened. Sometimes the bubble doesn't transfer heat to the pellet in the thermostat as quickly and you'll see an uncharacteristic high temp on the first cycle. Then the thermostat opens and the bubble is flushed to the radiator cap area.

The radiator cap has a check valve on it. When the system cools the first time it will gulp coolant from the catch tank to fill it's self back up.

Top off the catch tank ajd keep an eye on the level and the temp. It should come back to normal.

A note in this: I haven't directly worked with purging the FJR cooling system, but what you described sounds very familiar to most any engine.

Sounds like there was an air bubble in the system. Sounds like the system is working the way it should. If there is air in the cooling system a negative pressure will develop as the coolant cools and this draws coolant from the overflow bottle into the engine, just like yours did. Keep refilling the coolant over flow bottle until it no longer gets drawn down lower than the COLD line.

Sounds good to me. Can take a couple hot/cold cycles to clear the air. You don't have to leave it until the fans come on, but no harm in it. Betting your final reservoir level now is just above max. Good to go.

Thank you very much for the info/help!!

Did this last night: Coolant was right at the low line in the reservoir and I filled to the high line. By the way, from the low to high line is 100 milliliters; for us south of the boarder I’d guess it to be 3.8 oz. Started it up, let it idle, at four bars blipped the throttle a few times, continued to idle until the fans came on then shut down. When I checked it this morning, coolant level was right in the middle of low and high marks. I will add 50 milliliters tonight, go through this cycle again, see if it pulls more in and report back.

At this point after two cycles of heating it up and cool down it has pulled in 250 milliliters from the reservoir.

In my experience, when the bike is stone cold, there's no point filling the reservoir above about 1/3 up from the minimum level. I've filled higher than this, only to find it's back at this level next time the bike is cold. After that, no more is lost.

Image below shows my bike's cold stable level
(Click on image for larger view)

Did a third heat up and cool down last night. When I checked reservoir yesterday morning it looked like it was halfway between the low and high marks, when I looked at it last night it was closer to the low mark……maybe I didn’t give it as good of a look as I thought. I’ll say it pulled in 90 ml after the second heat up and cool down. Added another 100 ml which put it about an 1/8 of an inch above the high mark, warmed it up good and took it out for a short ride. When I came out this morning it was about 1/4 inch below the high mark, so it pulled in about 20-30 ml more.

My ride last night had a couple fun turns on a hill, I rode it in both directions a couple times. I’m thinking leaning in to the turns left and right, up and down the hill, shook a little more air out of the system. At this point I have added about 2500ml/2.5L, for us south of the boarder 2.64 quarts. Since I didn’t flush the whole system, just drained and refilled I’d say it shouldn’t pull any visible amount from here. I did check the sight glass for the oil and all I see is oil.

Rode it to work today and will keep you posted.

I'm thinking at this point you need to start all over and do it right with a WarXXXXX blowjob change. <kidding>

wheatonFJR wrote:I'm thinking at this point you need to start all over and do it right with a WarXXXXX blowjob change. <kidding>

Solving for X. If X is multiplied by War...

War(X) then X must equal Douche. But since X is multiplied by itself five times then the equation equals WarDouche to the power of 5.

That’s a lot of Douche.

And logically if we’re discussing the WarDouche Blowjob to the power of five...

WarDouche is doing a lot of Blowing.

So...

WarDouche to the power of five + an awful lot of blowing = free bike, gas cards, and a room at a rally.

NOW I get it.

0face wrote: ↑Wed May 16, 2018 1:27 pm

wheatonFJR wrote:I'm thinking at this point you need to start all over and do it right with a WarXXXXX blowjob change. <kidding>

Solving for X. If X is multiplied by War...

War(X) then X must equal Douche. But since X is multiplied by itself five times then the equation equals WarDouche to the power of 5.

That’s a lot of Douche.

And logically if we’re discussing the WarDouche Blowjob to the power of five...

WarDouche is doing a lot of Blowing.

So...

WarDouche to the power of five + an awful lot of blowing = free bike, gas cards, and a room at a rally.

NOW I get it.

^^^^
subtlety is not your strong suit I'm guessing...

Sounds like deang has got it under control...a lot of good discussion/reminders in this thread.

Yes I believe it's under control now. After a couple rides it isn't pulling in anymore fluid. Thanks again everyone for your help on this!! Hope this helps someone down the road.