Measuring Radiator Flow

 Is there a DIY method to measure the flow-rate of coolant through a
motorcycle radiator?  My bike is 12 years old and I'm wondering if
there's been enough scale build-up in the radiator fins to reduce flow-
rate and the water-cooling efficiency of the radiator.  I've looked in
the bike service manual and it gives no information on how to test for
flow rate.   TIA for any tips or suggestions.

Manjo

 
What kind of unforeseen, mysterious problems does your
bike surprises you with?
 Temp needle in red zone?
 You get hot knees?
 It steams all the way?
 It burbs when you switch it off?

In other words, if there aren't any problems,
why do you search for a cause?

Just think for a second. Why would the manual
not define a flow rate, let alone how many miles
you may ride before you need to check it.

Rob.

 
Probably also be OK to do a radiator flush
and throw in new coolant if in doubt. Might
be way less trouble than trying to measure it.

Never owned one of those newfangled water
cooled bikes myself, so take it as pure speculation.

 
Hi Rob,

Thanks for your thoughts.  Perhaps you could help if I give you more
information.
I ride a V-twin with 125k miles (117k miles are mine).  In warm
weather (above 80 degrees F) the bike will stall out at stops while
the rpm's fall under 800 rpm.

I've rejetted the carbs, sync'd the carbs, set and reset the idle
speed, cleaned the air filters,  confirmed the cam settings, changed
the fuel filter, checked the fuel pump flow, etc.  I'm pulling the
engine this winter and checking the bore and heads.  I have to
disconnect the radiator again and can easily test it standalone.  I'm
looking to eliminate as many heat causing and heat dissipating
possiblilities as I can while I have the engine out and apart.  Low or
slow coolant flow could cause an overheating problem.  What are the
other possibilites to check?

Thanks,  Manjo

 
I'd check the compression, ignition timing, and make
sure the head gaskets were not leaking.

I normally set my idle above 1000 RPM. 800 sounds
low and I'd expect mine to stall at 800 too.

Can you check the oil and water temps ?
Are you certain it's overheating ? Onboard
temperature guages are something I really
appreciate.