Yes, took me a few goes to get the level right. I did the same as you and siphoned the overflow bottle.....madness to follow the Honda directions.

 

I am now wondering about the coolant I have used. I have used ready mixed Honda Pro type 2 coolant.
Just noticed that the workshop manual says use Honda Pro HP coolant . The stuff I have used does not say its silicate free, does not even mention motorcycles or alloy engines.
I am pretty sure the Honda Pro type 2 is the right stuff but what is this 'HP' coolant.

 

I am now wondering about the coolant I have used. I have used ready mixed Honda Pro type 2 coolant.
Just noticed that the workshop manual says use Honda Pro HP coolant . The stuff I have used does not say its silicate free, does not even mention motorcycles or alloy engines.
I am pretty sure the Honda Pro type 2 is the right stuff but what is this 'HP' coolant.

Sounds like the same stuff.

HP ("Hi Performance") Coolant Type-2 Ready-To-Use 50/50 Blend Pro Honda has a non-abrasive (no silicates) corrosion inhibitor.

 

Coolant used to be a big issue on what one to use back in the day because aluminum rads were starting to be used. Coolant had a slight acidity to help keep the rads from oxidation and clogging, fine for brass but bad for aluminum. Now I don’t think you could even find any brand that isn’t rated for aluminum. But that said something with a higher heat dispersion rate is recommended and is better for adventure bikes simply because of the way they might be ridden; slow speeds high RPM’s a lot of acceleration and deceleration in short distances plays hell on the cooling system to keep up.

 

With rad and overflow tank filled with new coolant i followed instructions and ran the bike for a while with rad cap off and blipped throttle to burp out any trapped air in pump etc. It dropped a little so i topped it up.
Finally its cap on and get it up to temperature so thermostat opens and coolant circulates properly to remove trapped air. After cooling i removed rad cap and found level had dropped a lot. Refilled and repeated the hot run. On cooling found the level had dropped again by quite a bit, topped it up again.
Has anyone else found that the level dropped like that ?

I think the key to filling and capping the system is to fill the rad to the top and leave the cap off. Then start the engine and forget blipping the throttle to get the fluid level down. Run the engine until it is hot enough for the thermostat to open. When this happens you will see the coolant level drop quickly and there will be no doubt if you are watching when the thermostat opens. At that point shut down, refill and cap the rad. You may want to put some antifreeze in the overflow but don't fill it up. Go for a ride and check the overflow after. If it is low add to the fill mark. If it is overfilled you may need to siphon a bit out.

 

Just like with a cage.

 

I think that is good advice from Bill J about running the bike with the rad cap off until the thermostat opens. I did wonder about about the 'cold' run and blipping the throttle as unless the thermostat is open there is no substantial flow path for trapped air to get to the radiator and indeed it had no effect on level for me. I suspect Honda dont advise the cap off hot run as its a dreaded health and safety issue with the potential to get splashed with hot water.

 

Yep, old school method taught in high school automotive shop course. Children are not supposed to be doing radiator flushing activities.

 

With my 2018 ATAS about to hit a piddly 8k miles (5k last year when I purchased the bike used), I’m going to force myself to do the coolant change this spring. Just ordered what I seems like the correct stuff.. here we go!

 

Doing a bit of service work on my 18 ATAS and coolant is one. You can remove the side panels on the ATAS with the light bar in place if you're very careful and patient on removal. Hanging a towel over the lightbar in between the panel and bar helps pevent scratches. You can also remove the two lightbar mounting fasteners under the headlight to rotate the bar forward.

I actually had the rear wheel and shock off doing other stuff and forgot to empty the coolant reservoir so just did similar to the OP with a tube and syringe. I used the Pro Honda HP coolant, it's the correct stuff and just under 2 liters. Turned my hoses blue though.

 

Good lookin’ hoses! Perfect, syringe and 2 liters of coolant on the way. This will be a good project and nice for when those temps start climbing.

 

Do you smell coolant? If so, there's a bleed pipe on the bottom right side of the engine under the water pump which allows some coolant to weep out under certain conditions every so often. Not a cause for concern unless it's a constant thing.

 

@MoDirt: It is unlikely an overfill will damage the cooling system. The system needs to weep out excess through the overflow/reservoir if it gets too hot. Otherwise you'll get some sort of "steam whistle" leak - nobody wants that on a motorcycle. The same issue applies to fuel-burnin' automobiles.

 

Good to know. Except now I’m wondering where the little bit is going soon after filling up since I don’t notice it leaking out, so am back to thinking it’s possibly got a leak in the water pump or that the pump might not be working right which is causing it to overheat and use up coolant faster. Either way not great but I’m taking it in for a diag Friday so will hopefully know something soon. Thanks for your help. Cheers.

 

@MoDirt: What does your oil dipstick look like? Take an engine oil level reading.

Is it higher than expected?

Wipe the dipstick on a white paper towel. Does the oil appear somewhat "greenish"? Does the oil smell "off" - like sweeter than it should be? (Note: Fresh Motul 5100/7100 can smell sweet out of the bottle, but most oils do not).

 

I’ll check again tomorrow but I hadn’t noticed that recently when I checked it.

 

Yeah it seems like it’s 3 bars all the time after not much warm up time. But if anything I think the fans seem to kick on late. I didn’t think the thermostat was the issue since I’ve read so many posts suggesting the 3 bars all the time is just how this one “works” if that even makes sense

 

Unless you are regularly losing cooling fluid, that is, typically the level can jump up and down a bit from ride-to-ride, but hopefully not down, down, ... down - then you are probably okay.

 

My fear with letting the excess just come out of the reservoir is that it could contaminate the road just ahead of the rear tire. Not a place I want to be leaking a slippery substance.

 

I'm at the coolant change stage in the service schedule, and was horrified to see the official technique involves removing the rear shock! Madness. I try to avoid unnecessary work like that, as there's a chance something will go wrong (and knowing the standard of work we get from many main dealers in the UK, a high probability they'll get it wrong). So BigKev's syphon method sounds very sensible. Thanks.

 

Hello, have more details about the siphon technique shared in the forum? I'm also thinking of changing the coolant. I have a crf1100l at the 2020 model 18000 km. No changes have been made for 5 years. It is stated in the user manual that it should be replaced every 3 years. Do you pay attention to this range?