Cooked the Little One and now

[skelz]

Got caught out today and had to drive the "Little One" in on a very hot day..I am fairly sure she overheated as a had a loss of power.. on the way home we was backing firing and was idling rough..  now she has cooled down she starts okay but wont idle at all. 
The oil is nice and dark so I will replace that first up.
I hope I havent stuffed her too much
I will keep you informed of what the diagnosis is..

[Pete126]

Sorry to here that Skelz,

Start with the basics, Points Reset if necessary Check the Static Timing If its too far advanced the engine will overheat, Plugs and Plug leads if it still missfires replace the condenser, then clean the carb out

[Darrell]

Mine overheated fairly regularly when I had that !%^^!@! elecronic ignition set-up that advanced the ignition too much. Don't know why but will get to the bottom of it eventually as I seemed to be the only one who had issues with that brand of electronic ignition however...
After all that overheating I had a rear main bearing pinch-up on the crank which took a chunk out of it. I lost oil pressure.
With a little luck yours has not even done this and will be fine [-/
But like Pete says, it's critical the ignition advance is set right.

I'd look into an oil cooler.

[Rusty's Uncle]

Before you panic about over cooking the engine bear in mind that the aircooled engine was designed for & will run OK in some pretty extreme conditions. It gets quite warm in Italy & they used 500s in the Antartic. As for extreme engine heat then I have been there when my cooling fan blew and the powder coating on the rocker box cover blistered with the heat. Very close to disaster but got away with it. As Pete says , start with the usual suspects. Also I would add make sure the Jumbo cooling inlet hose is properly connected and the carb has not worked loose  [-/

[skelz]

yeah thanks I do have an 123 electronic ignition fitted but it was an extremely hot day.... and the little one was working pretty hard... it might be wishful thinkin but as it starts easy and revs easily.. the idle being the only issue. I am hopefull its nothing major

[Darrell]

How hot was extremely hot?

[skelz]

At a guess  mid 30s.. I had it going at 80-100km/h for a fair while and then got  stuck in traffic.. whilst no paint bubbled off it got hot enough to loose power.. Its my own fault really.. but I didnt have much choice. wife had the main car and i had to get somewhere in a hurry..

[Darrell]

Mid 30's shouldn't be a problem, I was in Rome this year and it was about that fr a few days. Traffic shouldn't bother the engine as air is 'pumped' past the barrels.

Was it pre-igniting? Pinking?
Thermostat flap opening properly (I pull the whole housing off during summer)

[damon500]

Hi Skelz,

Sorry to hear the news but I think it is extremely unlikely that you have cooked it- my 500 did 6000km in 4 weeks through Europe in Summertime and was fully loaded with two people, luggage, tools and camping equipment - we were sitting on 100-110km/h for hours on end (did 6-800km some days in 35-40 degree heat) and then sat in Italian traffic for hours also. That car has an absolutely standard Niki motor that has now done over 100,000km.The only extra thing I do is always use good quality full synthetic oil- I currently use the Selenia Racing 10W60 which is the genuine oil for the Alfa Romeo 2.0 engines but the Castrol edge sport is also good and the 5 litre pack will do two changes! Have used synthetic oils in my 500's and 126's as daily drivers for the last 20 years and have never had a single engine failure.
I don't know why anyone bothers with electronic ignition- the standard system with twin outlet coil is very reliable provided the distributor cam is lubed occasionally and it isn't as if the dwell angle is that critical (we don't have 8 cylinders to worry about...!)
Before you start worrying too much check the idle jet isn't blocked- it is behind a brass 'Screw' at the front of the carb towards the top- pull it out and remove the jet- often there can be some debris blocking it. Also make sure the carb hasn't shaken loose creating an air leak below- carefully tighten the 10mm nuts at the base- not too tight or you can distort the carb base and crack the insulator block. Good luck! 

[skelz]

well i hope ya rite.. I will change oil with some good stuff and check the carbi jet and will post a vid of how things go.. As the the electronic ignition a fiat lover at work recommend them to me... It wasnt cheap so hope i havent done my dough.. I coulda brought something more useful like wheel cover or flash rims... Haha

[Alfons1972]

I first would check the valve clearance...

a different possibility: if my engine does not start if hot, I have to check oil level. in that case it is often too low... 

[gsxr126]

Yeah................bad oil will do those kinds of things to your motor. Hope you havent stuffed it. Its either fuel or bearings as overheating rarely affects the spark, so check those bits first, as pointed out above.

Is it noisy... um noisier than before when its idling? Can you hear rattles from down below? You'll be able to hear a really stuffed bearing, sounds like a knock. A slightly stuffed bearing will sound like its pinging.
Dont ask me how i know this

I would change the oil as a priority (after you find out the bearings are ok) and use the stuff Damon uses. I use the same grade but different brand and after 45 thousand kays of daily driving, can vouch for what Damon says.

Let us know how u go [-/

[skelz]

Update !!
After
tighting carb mounting bolts (about half turn on each without really swinging off them)
changing spark plugs (just because I can)
Replacing oil... (old stuff blackened after heat issue).. Nulon as suggested ..did spill a bit oops!!
Cleaning Carbi jet

The car wouldnt idle.... Start great, run with choke on (even slightly cracked).. but once off it would die..I had a play with the idle on the carbi and now seems to run and idle alot better but still has a putting slight backfire when going down the gears.. Maybe it was there before and never noticed it ??

there is definately air being sucked into the side vents of the car.. But the large diameter trunking that connects on to the fan has seen better days.. So a new one is required.. Any fellow Aussies know if I can get this stuff from (industrial Aircon or fireplace installers spring to mind).. I still think the engine in general seem to get very hot fast..

As for the timing I might drop in and see my mechanic or venture over and see the fiat dr even just for my own state of mind..
I think the thermostat/air flow flap might of ready be missing does it normally live above distributor or that general direction ?
As for rattles or funny noises.. no I am not noticing any significant changes to engine melodies when compare with before the "incident"

Thanks again to all

[skelz]

here is a vid of the little one... Is this pinging or the purr of a 650cc powerplant ?
http://www.youtube.com/watch?v=dumDiUYWgdQ

[GTMaster]

There seems to be a strange knocking noise... and when revving it didn't sound too healthy in my opinion... if it doesn't idle but starts good when cold and runs with the choke on then the idle jet is probably dirty (needs to be taken out and cleaned). Was the valve clearance  checked on it recently?