Cooling the Engine ...

[Luther]

So if a 500 will never puke water from overheating, theres probably not much chance of ever seizing a piston either? Is that what your saying Gareth? And if it ever does seize the odds are 50 50 whether it will be a front or rear that locks up? How many front seizures have you seen? Any?

Hey i'm not trying to be a know it all. I've only ever seen one 500 other than mine run. Tony Baker started midpack and finished 4th in a combined classes 30 minute race. Only a few watching knew he was on an oddball bike. It had a big radiator and we were in Colorado where the weather is cool, maybe like the UK. Not hot weather like where I live or god forbid one of those desert valleys in Kalifornia. I've done a few trackdays on my 500 but its not really set up for that, its heavy and runs kind of HOT compared to my racebike.

[Gareth]

No, thats right they dont seize if everything is OK...good oil supply..right clearances, full of water, correct timing, right jetting, and Good condition parts replaced at the right times..... then it will never seize. Get one of the above wrong and it might....Start thrashing a carbon coated 20,000 miler with a badly set up oil pump, dogy worn powervalves, gumbed up rings, dodgy crank seals and loose cranks..then you tend to get problems.

...I had alot of rear seizures at one time...but i found out (by examining the piston and looking up what the markings were telling me) what the cause was....I never had a single overheat seize...they were all lubrication breakdown - and not through overheating.

Come on...if its not boiling the water...its not hot is it...the pressure cap raises the boiling point to what..110deg. Ideally thrashing along I like mine to be around 70deg but it sometimes ends up around 90 during a serious thrashing on very very hot days....not a problem....Its a compromise...I'd rather have that than be fannying around taping rad up on cold days. I do not take thermostat out or use a lower rated one either.

[Shaftoflame]

Have had the fan come on once - stuck in slow traffic on the M5 bank holiday Monday and stinking hot - even filtering through the traffic was moving real slow. I think the traffic had backed up from Taunton right down onto the A38 past Exeter. Why was I on the M5 - to get home in time for work - eventually carved off onto the A38 and had a ball - was late for work anyway.

Got hot enough coming round under the M25 (not on it) one summer - hot enough to melt the zorst covers at the back - but fan not on temp not near the red zone.

Used to block off half the rad in the winter so it would warm up and stay there - I know it has a thermostat but seemed to make things better. Would take the card off about May time

R

[ChequeredFlagRacing]

Could someone re-post the pictures of the extra water cooling lines to the rear cylinders please

[smokamoto]

Here’s how I did mine...your results may vary.

[BigGuy]

Good pics, thanks for posting!

[silverstrom]

Extra cooling for the rear cylinders is nice, but as was pointed out to me recently, you need to keep in mind that overheating issues are also related to the rear cylinders running hotter due to the rear crankshaft being retarded, so the ignition is advanced. Correct that problem, with either an offset key (or different pistons that have the pins centred, apparently, such as TZR250 2MA pistons) and you'll solve part of the overheating issue.

[smokamoto]

Extra cooling for the rear cylinders is nice, but as was pointed out to me recently, you need to keep in mind that overheating issues are also related to the rear cylinders running hotter due to the rear crankshaft being retarded, so the ignition is advanced. Correct that problem, with either an offset key (or different pistons that have the pins centred, apparently, such as TZR250 2MA pistons) and you'll solve part of the overheating issue.

Agreed Silverstrom, both rear cylinder cooling & crankshaft timing should be corrected.

[ChequeredFlagRacing]

Thanks for the pictures smokamoto

[smokamoto]

Big & Chequered you’re welcome.