ok replaced the coolant on the 30 around a month ago , but i noticed when the bike is hot the hrc expansion bottle fills with a grubby black looking coloured coolant , not the bright blue that went in , so i drained the system and with the drain bolt out attached a hose pipe to the rad and flushed through for 10 mins,
on refilling with fresh i noticed i can only get 1.5ltr back in, i always thought the system holds 2ltrs however ive revved the bike squeezed the pipes and took her for a spin , gave it loads of welly through all the gears thinking air lock , when up to temp the hrc bottle part fills and its a good clean blue colour so i belive the system is clean , but only holding 1.5ltrs , i did notice with the cap off and giving it a rev the coolant drops an inch or so then as the revs drop the fluid pops up again , i dont think it did that before well not as much anyway , i might just add that over the winter the system was filled with tap water while the bike was sat in the shed as a temp measure while i test fired the motor after fitting it back in the frame , so do you think the water has sludged up in the system causing a blockage ?

From your description it is unclear if you removed all three drain bolts when draining the coolant.

no i just removed the drain at the pump , last time i removed the 2 at the front i had trouble getting them back in as there is limited space , im guessing that it has not completly drained the system then

Deviant400 wrote:no i just removed the drain at the pump , last time i removed the 2 at the front i had trouble getting them back in as there is limited space , im guessing that it has not completly drained the system then

Strange, when I did my system flush etc I didn't touch the front two drain bolts, just the one on the water pump housing.

Did you drain the system on a paddock/abba stand? or on the side stand?

I did mine on my abba stand, but the bike was sat overnight in the garage so I had to put it back on the sidestand so my dad could get his stuff out. When I stuck it on the sidestand alot more coolant came out.

Plus when I changed my radiators I didn't put the bike on the sidestand but still used about 2.5 litres of premix, so I'm guessing the system was fully drained.

From logic alone my guess is a blockage....

yeah all done on the side stand , got some rad flush now so looks like ill have to give it a go

It sounds fine.

If it's running I wouldn't mess with it.

Only when doing a full flush to I get the drain bolts under the front headers out.

It's likely you've just got some coolant still throughtout the engine which has made up the extra.

The coolant will drop with the cap off when you rev it up.

kool , i done a proper rad flush ,drained system , added rad flush , done what it said on the tin , removed all drain bolts ,flushed through with clean water , replaced all bolts refilled , this time just under 2 ltrs went back in

probably some coolant still in the pipes taking up the excess. keep an eye on the temp gauge but it should be ok