Tuning 1970 500F Uphill Challenged!

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Tuning 1970 500F Uphill Challenged!

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Sep 9, 2014
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I had some head work done on the number one cylinder as my valve seat cracked and I lost compression. So I brought it to a shop and they did a really great job of repairing and installing a new valve seat. So while I had the head off I figured I'd give it a new set of valves as well. The car runs very well now with the exception of going uphill. It seems to labor a bit and I lose speed now which really wasn't like that before I had the top of the engine dissembled. Flat surface and downhill (of course) it runs like a champ. Any ideas as to why this would be happening?
 
First, did you change or adjust anything else like ignition timing, points, etc.? I would re-check valve clearances. After doing the valve adjustment, recheck the compression in each cylinder to see if they are good. Cylinder head may need to be re-torqued.
Then you might try adjusting the mixture slightly either more lean or more rich and run up the hill after each adjustment to see if there is any improvement.
John
 
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Many (and I do mean MANY) years ago whilst my new wife and I were on our way to where we were going to spend our honeymoon (a hamlet in Cornwall called, Puddle) we had a similar situation with my 500. It turned out to be a blockage in the carburettor. Prior to leaving work on the Friday before we left for our honey moon (which because Ann was a teacher, we had to wait a week after the wedding so that we took it in the half-term---they wouldn't give her the week off after the wedding!) my Fiat 500 had been covered in a white 'powder'. In fact what it turned out to be was what was left over after the perforations had been punched out on a sheet of postage stamps---the brother of one of the mechanics at work worked for the post-office, and they thought that the 'punchings' would make good confetti! Well somehow, some got into the fuel, and then the carb. Outcome? the car would struggle up hills and everything, including pedal-bikes would pass us, and then when going down-hill, the carb would get onto the main-jet and the car would absolutely fly--we passed everything going downhill that had passed us when going up. A quick clean-out of the carb, including jets, when we got to our destination returned us to normal running. I would back-up the suggestions by John, with the addition of---give the carb a good clean out.
P.S.----there are an awful lot of hills in Cornwall!
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First, did you change or adjust anything else like ignition timing, points, etc.? I would re-check valve clearances. After doing the valve adjustment, recheck the compression in each cylinder to see if they are good. Cylinder head may need to be re-torqued.
Then you might try adjusting the mixture slightly either more lean or more rich and run up the hill after each adjustment to see if there is any improvement.
John

I failed to mention I have a 1-2-3 ignition. I checked the timing according to the posts here and it seems fine. I will mess around with the mixture screw and see if that helps a bit.
While the engine was apart, I did a thorough job of cleaning the carb and bought all new gaskets for it. I will give the tappets a check to see if they need adjustment. I should check the compression out as well. I hope that's not the issue though!
 
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