Coolant puking out of overflow tube

[2linby]

Completed a major service on my 2016 FJ09 at about 23,000 miles (including a coolant change. I now have over 27,000 on the bike with before my IBA BBG1500/SS2000 Gold ride attempt (made both) I had no issues until yesterday during a very long ride home from Haugan, Montana. The bike started puking coolant and the engine check light came on while the overflow tank was full. When I got home the temp gauge read 260 degrees (HOT!) and the fan was on. Checking it out this morning the over flow tank is again full but the radiator was low about 7 ounces. I refilled, fired up the bike, at 221 degrees the fan came on and it started puking coolant again from the overflow, about 4 ounces or so. I waited for the bike to cool down, opened the radiator cap, again low. I topped it off with about the same amount and fired it back up. This time no overflow and again the fan can on at 221 degrees.  My question is why did it start to overflow after putting on almost 2000 miles before my BBG/SS2000G attempt? and not manifest a overflow leak before this long ride?  

Any thoughts? Air in the system? 

[knyte]

That is strange.  If that'd happened straight away I'd suggest air in the system, as you suspected.  I suppose it's possible it could take a few miles to produce symptoms like yours, but that's not usually how it plays out.  Best I can offer would be to drain & refill again with a clean 50/50 mix.

[peteinpa]

Try a new radiator cap.

[bwringer]

9 hours ago, peteinpa said:

Try a new radiator cap.

Agreed. The old one may not be maintaining pressure, which would allow the coolant to boil and overflow at a much lower temperature than it should. That's the simplest and easiest possibility, anyway. (I don't know whether there's an easy to find crossover to a car radiator cap, or if you just have to order one from Yamaha and wait.)

The other group of possibilities are about insufficient flow. If coolant isn't flowing, it will boil inside the engine and cause overflow. 

You could have a problem with the water pump (damaged impeller, perhaps). Put on a glove, grab a radiator hose and squeeze a bit. Rev the bike up. You should be able to feel water flowing and expanding the hose. Try different hoses -- if the bike is cold; the thermostat probably needs to open to allow flow. I'm not 100% clear on the FJ-09's coolant flow plan, but you may be able to feel flow in the smaller oil cooler hoses before the thermostat opens.

Which brings us to another potential problem, the thermostat; if it's sticking closed coolant can't flow. You can use the hose squeezing test to figure out if and when the thermostat is opening. You can also (carefully!) feel when the radiator or water pump outlet hose starts to get hot, indicating that the thermostat is opening. I can't find a spec in the manual, but most thermostats in modern vehicles are supposed to open around 195 F, and should be fully open by about 200 F.  

And then you get into more exotic possibilities, like a collapsed hose. Once in a while on cars you encounter a hose feeding the water pump that collapses when you rev the engine; some have a spring inside to prevent this, and sometimes a hose is just old and oil-soaked and gets too soft to stay open. This seems very unlikely on a relatively new motorcycle. Same for things like a radiator or coolant passages blocked with corrosion; these can happen to really old, neglected, high mileage cars but are very unlikely in this case.

Lastly, a comment: I don't know what's standard, but the radiator fan on my 2015 FJ-09 turns on at about 205-206 degrees F. Yours turns on at a higher temperature. However, I know my bike's ECU has been flashed, and some flashes lower the fan temperature, so maybe that's it. I don't have any information about what was changed when my bike's ECU was flashed; the PO didn't remember and didn't have any documentation.

 

[peteinpa]

What coolant did you go with?

was it a concentrate or ready to use?

Got to run it to full warm without the cap, then lightly rev the bike to burp it.

[roadrash83]

Any sign of coolant in the oil or white smoke from the exhaust? That would indicate a blown head gasket. Any bike shop should be ably to pressure test your radiator cap for you.

[2linby]

Coolant is Engine Ice ready mix. No coolant in the oil or white smoke. The bike is running fine.  This was a hard run for over 2600 miles of which over 2000 was done within 36 hours.  I probably had some air in the system and never ran hot enough until this trip. I'll try burping it again. But so far in two days commute no issues, no leaking, but temps have been under 180.  

[PhotoAl]

years ago had a problem with my BMW F800GT, rolled into Grand Island after a long hot day and the bike puked out a little coolant.  Reservoir was full so I didn't worry about it - bike was serviced at the dealer and always had all the services done on time.  Didn't really have any problems with it until almost back home - 2 miles away after over 5,000 miles.  Bike overheated and flashed all the warning indicators.  Was sitting at a traffic light and didn't notice until light turned green and we started to go.  I couldn't stop immediately but the bike cooled very quickly and I made it home.  Took it to dealer - story I got was the engine had water in it, hummmm wonder how that happened since they were the only ones who touched the bike since it was new.  IMO someone made a mistake of draining the coolant under an old schedule and didn't want to fess up so just put water in it.  That engine needed to be vacuum filled or would have air pockets.  Between the water and air pockets the bike would boil some water off but reservoir would look full.  By the end of the trip the radiator was so low the fan could not pull enough air across radiator tubes that had water in them to keep the bike from overheating.  At speed it did not have a problem.  IMO a very robust cooling system.  

Not sure what is causing your issues but I would check to make sure you do not have any air pockets and the engine has proper coolant in it.  Having cap tested not a bad idea either.  Since your problems started after the service I would tend to think something happened then rather than something like a blown head gasket.  Would also look at the thermostat and unlikely but water pump may have an issue but based on what you have seen I don't think it is the problem.

[2linby]

Thanks everyone for your suggestions. So far I believe I did not have all the air evacuated from the system and running it so hard, well....  I will again "Burp" the bike this weekend. But so far since being home and commuting everyday there hasn't been an issue. But the temps have not been over 180 on the bike.  Again, Thanks!

[betoney]

14 minutes ago, 2linby said:

So far I believe I did not have all the air evacuated from the system and running it so hard, well....

What do you mean when you say "running it so hard"?  If the cooling system is operating correctly the bike should be able to operate 24/7 literally forever and not overheat.

[PhotoAl]

Last year in Utah when the temps were 95F and I was running 35mph and a rough road noticed my temps were slowly creeping up as I went uphill for a ways.  Was a bit concerned about my return trip as I had to climb out of a canyon (Jones Hole near Vernal).  I spend a couple of hours down there and the bike was cool when I started and had no issues at all.  It did seem like 35mph was a bit slow for good airflow over the radiator, probably would not have overheated but did catch my attention when the temps were inching above 205F. 

[2linby]

14 hours ago, betoney said:

What do you mean when you say "running it so hard"?  If the cooling system is operating correctly the bike should be able to operate 24/7 literally forever and not overheat.

1546 miles in 23:07 and 2021 miles in 35:54. and 2600+ overall in less than 48. For the most part the bike was off long enough to gas up and go. 

[betoney]

2 minutes ago, 2linby said:

1546 miles in 23:07 and 2021 miles in 35:54. and 2600+ overall in less than 48. For the most part the bike was off long enough to gas up and go. 

Congratulations on the achievement, you have much more endurance than I do. 👍

Its good to hear that its operating normal again.

[2linby]

Up date on my radiator overflow issue. After waiting almost one month for a new radiator cap, it was the cap. Problem solved. temps cooler and no more draining the overflow tank and refilling the radiator with my mity-vac!

 

[peteinpa]

No applause, just 10's and 20's.😁