System Flush Question
 

I plan on flushing the cooling system this weekend. I currently am not having any cooling issues. No leaks. It's just that it's got 15K miles on it and the coolant has never been changed. I notice in the manual it calls for replacing the sealing washer on the drain plug. Is that a must do item or should I be able to re-use the old one? Also, it calls for running a flushing solution through the system. Is that really necessary or can I get away with just running water through it with a garden hose until it runs clear? I bought the "wetter water" to refill with. Any tips on it's use?
As always, thanks for everyone's expertise.

I didn't get a new washer, but YMMV.

I pulled a radiator hose and flushed with a garden hose till it ran clean.

Then I rinsed well with distilled water to get the hose water out.

Then I filled it with ~ 80% distilled water, ~20% antifreeze, and water wetter. (use water wetter's recommended amount, more is worse than the right amount)

If you live or will ride somewhere that temperatures get into the freezing, run 50% antifreeze. Water wetter does not provide any anti freeze protection.

In AZ I "could" have run just water + wetter, but I have ridden into the mountains on snowy days on rare occasions so I figured some antifreeze would be smart.

Lazn- any noticeable difference between running with water wetter and without?

Did pretty much the same as lazn but changed the 30 cent washer.
Filled the system with distilled water, ran the engine up to temp and then drained out the water (twice) before doing a final fill with Honda anti-freeze mix.

i wouldnt use a garden hose, only distilled water.

not on the analog gauge for max temps.. I probably takes longer to get there, but the max temp will be hit in Phx as set by the thermostat & fan switches no matter what coolant you are running. It certainly can't hurt if you only add what is recommended. (it is a surfactant, IIRC you accidentally added soap once, and that can do the same thing, so you may not need it)

Yep, I added soap! Pretty flushed out though... actually, while not trying to thread jack, I've had mixed reviews on ratios. Being in PHX, I am wondering if I should use more distilled water and less antifreeze as you have...

water is better at cooling than antifreeze, but antifreeze provides protection against corrosion and freezing.. I'd run more water here since it rarely freezes hard. But if you ever go north in the winter thicken up the mix.

If you plan to do track days, don't use any antifreeze, most tracks don't allow it. (just water wetter + distilled water)

This may be kind of strange but here goes:


Drain old coolant.

Refill with vinegar solution (2 cups white vinegar and as much Britta filtered water as needed).

Run engine until warm.

Drain vinegar solution.

Fill system with filtered water, run engine a few minutes then drain. DO THIS TWICE

Fill with your recommended coolant mixture (I think coolant is needed to lube the water pump).



After this drill, I swear the bike runs cooler. My '98 doesn't have a digital temp gauge but the needle position reads a little cooler than before the flush. I reused the old drain plug washer.

I don't want to jack your thread, nor do I want to start a nearly identical one, and you may benefit from this question too so here goes.

Does anyone know why you could not use another brand of quality anti-freeze other than the Honda type?

I followed Lazen's suggestions. 80% distilled water, 20% anti-freeze (I used Prestone), the 3oz of water wetter. Worked out fine. I got a little teasing about changing the washer on the cylinder drain plug. I asked because I thought it might have been a special washer, like a crush washer. Had I known it was just a plain old washer, I wouldn't have been concerned. Anyway, Everything went fine, removing the fairing is a bit of a PIA but dooable.

I used Prestone. Being in South Florida, I wasn't going to use any anti-freeze but changed my mind after reading the responses. I don't know if one brand is better than the next.

The washers are copper. If you don't want to buy new ones you can heat them up to cherry red. This anneals them and makes them soft so they can crush again.
I always use Honda Car antifreeze it's like $2 more than Prestone and it is spec'd for Honda motors. The important thing is to use a silicate free type or it will eat your pump seals.

Interestingly the honda manual doesn't mention flushing the coolant, just simply drain and refill. Since my most recent change was only after 2 years and it wasn't a long time I just did it the "honda" way. The first time I did it the coolant may have been over 10 years old so I flushed with hose water without thinking. Nothing bad has happened since, but I would use distilled next time if I flushed.

I'm in New England so we don't even question not using antifreeze. I sometimes get concerned about the freeze temperatures of the antifreeze mixture as it is. I was really surprised to hear people saying they reduce the mixture. Makes sense though.