[Collin]

We just changed the coolant on a 2007 150r and put in Engine Ice. The first time we went riding, we went on some trails and rode pretty slow. It boiled over. I assumed it just pushed out the extra, but it did it again while riding very slow. As I started moving again, it quit. Thought this stuff was supposed to keep your bike cooler. We run hare scrambles and get into some slow sections, so I thought Engine Ice would help. I did notice when I took the cap off to drain out the old coolant the level was down a little. I now assume that the system can't be completely full or it will boil over. Anyway, that is what I am hoping. Anyone else have an opinion?

[crfsonly]

it sounds like you may have an air pocket in the system.

ken

[mikey526]

it sounds like you may have an air pocket in the system.

ken

Yes, I think an easy fix for that is top off the coolant (to the bottom of the filler neck) and lean the bike over until you hear it "burp". You just hear air coming out making ripples. Do this several times keeping the coolant level topped off each time you bring it back up.

[Collin]

OK, thanks. I suspected something like that. I got home and filled it up and haven't had any problems since then.

[Honda53]

i'm pretty sure its common on the 150 when riding slow trails. i guess you just have to add coolant every now and then

[Collin]

Honda53 you seem to be correct. The bike was running bad due to a bad valve, but the boil over I am experiencing is due to slow trail riding.

Interestingly enough, I never noticed boil over issues with the stock Honda coolant, but did notice it when we went to Engine Ice! We didn't do much trail riding until we switched though, so I don't think I can fairly judge the two based on that.

[the hawk]

When My Brother Starting Riding An Actual Race Bike, He Didnt Ride It Fast, After About 15 Minutes Of Slow Riding It Started Boiling Over. The Reason Your Bike Boiled Over Is Because You Bike Needs To "Actually Run" To Push The Coolant Into The Motor. And When The Coolant Sits There And Is Not Being USed It Boils It Till It Just Comes Out. Hope This Helped

[Asmith]

When My Brother Starting Riding An Actual Race Bike, He Didnt Ride It Fast, After About 15 Minutes Of Slow Riding It Started Boiling Over. The Reason Your Bike Boiled Over Is Because You Bike Needs To "Actually Run" To Push The Coolant Into The Motor. And When The Coolant Sits There And Is Not Being USed It Boils It Till It Just Comes Out. Hope This Helped

Huh???

When the engine is running, coolant is circulating.

[Collin]

Raced a Hare Scramble this weekend. On the practice runs it got hot twice. Both times was during slow technical sections through the woods. When I would come to a difficult section and stop and survey the best path, the bike would start to steam. As soon as I was moving, it would quit. During the race I was going fast enough that it never did boil over. I guess the secret is to keep moving, right? LOL Actually I did stop once and it didn't boil over, but that is because the bike stalled when I dropped it straddling a 15 inch log. Gotta love a 15 inch log on a bike with a 14 inch rear wheel.

[the hawk]

When My Brother Starting Riding An Actual Race Bike, He Didnt Ride It Fast, After About 15 Minutes Of Slow Riding It Started Boiling Over. The Reason Your Bike Boiled Over Is Because You Bike Needs To "Actually Run" To Push The Coolant Into The Motor. And When The Coolant Sits There And Is Not Being USed It Boils It Till It Just Comes Out. Hope This Helped

Huh???

When the engine is running, coolant is circulating.

The motor has to be doing something for it to circulate through. same reason alot of race bikes over heat more on the starting gate than on the track...My Little Brother Qualified For Lorettas This Year And I Watched A Bunch Of the Holeshots. There Were Several PPL Who Let Their Bikes Idle On The Line And Right Before The Gate Would Drop 2 or 3 would always go up in a big cloud of steam, didnt see many on the track actually do that

[Asmith]

When My Brother Starting Riding An Actual Race Bike, He Didnt Ride It Fast, After About 15 Minutes Of Slow Riding It Started Boiling Over. The Reason Your Bike Boiled Over Is Because You Bike Needs To "Actually Run" To Push The Coolant Into The Motor. And When The Coolant Sits There And Is Not Being USed It Boils It Till It Just Comes Out. Hope This Helped

Huh???

When the engine is running, coolant is circulating.

The motor has to be doing something for it to circulate through. same reason alot of race bikes over heat more on the starting gate than on the track...My Little Brother Qualified For Lorettas This Year And I Watched A Bunch Of the Holeshots. There Were Several PPL Who Let Their Bikes Idle On The Line And Right Before The Gate Would Drop 2 or 3 would always go up in a big cloud of steam, didnt see many on the track actually do that

The engine only has to be running for the coolant to circulate through the water jackets and back out to the rads. Running at higher rpms certainly makes it circulate faster, but it's always circulating.

The reason guys overheat when they are standing still is that no air is being forced through the radiators.

That has nothing to do with the circulation of coolant.

Airflow carries away the heat from the aluminum fins on the radiator core tubes. The core tubes conduct heat from the coolant passing through them. The fins seve to expand the surface area of the core tubes.

It is a simple heat exchanger.