General Franko the 1971 500L

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General Franko the 1971 500L

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Franko500

Franko500

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I guess I will need to do a few regular checks as I clock up some miles just to make sure everything is tight. Damn cheapo parts!
 
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Franko500

Franko500

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here's a little video of my 500.
[ame]https://youtu.be/FhxdA566-es[/ame]
Went for a great drive today.
All was good until I turned it off outside the mother in laws - Again!
thought we were going in for a cup of tea, but no we were heading straight out again. Guess what it wouldn't start.
No fuel in the filter. I took the fuel cap off but this made no difference.
The fuel level was just below half way.
Removed the hose to the pump, there was nothing for a moment then fuel started to come out. Popped it back on the pump, turned it over a couple of times and it fired straight up. So I better try sorting this problem out!
 

fiat500

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I wonder if it's something to do with the return pipe arrangement from the carb or the internals of the electrical cut-off switch there breaking the flow even though it's been disabled(from previous postings)?
The symptoms do still seem like the fuel cap breather. Have you tried driving to the mother in law's with the fuel cap loose or loosening it when parked up?
 
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Franko500

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The Weather down south has been dry now for almost a week and the roads have finally dried up. So today I took Franko out for his first drive this year.
He hasn't even been started since he was last parked up for the winter.
He started almost instantly, but he can be forgiven given how I woke him from a deep sleep and it probably took a few turns to get the fuel back up to the top.
I then took him for a nice drive to the petrol station for some fresh juice. His light was just flickering on/off and so I put £15 in which took him just over the 3/4's mark.
I had about 6 people look and compliment him before I set off again.
And then it started! He would be driving fine but every time I came up to a junction and came to a stand still, when I went to pull away he would almost stall when I put my foot on the throttle. I had to blip it enough to get it to rev higher before I could pull away. Once I was off it was no problem.
Got home, got out to open the garage doors and he stalled and wouldn't start again. Fuel filter is full to the brim but he wasn't going to start.
I haven't looked into the problem yet, too much else to do today.
Although I am thinking of changing the carb. I have never managed to get that anti run on solenoid to work properly, even with the one Tony sent me. So thinking of reverting to the standard 28 carb.
Any suggestions anyone?
 

IanEmery

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I've had similar symptoms and the problem turned out to be the idle jet was partially blocked. While I appreciate everything on your car is new, or thoroughly rebuilt, I wonder if maybe something has caused this plus it's a simple check to be able to cross it off the list.

If memory serves me my carb is a 26.IMB4 on which, after unscrewing the jet holder you pull the jet off the holder to check all of the drillings. Yours may be a later series and have a different method of holding the jet.
 
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fiat500

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Heck, it must have been dry!!:eek: Good for your soul to have been out in Franko but maybe not for your nerves and confidence.
It's one of those "your guess is as good as mine" jobs.
I would think laterally; the time when I most closely had those symptoms was once when the engine developed a flat-spot...the distributor was slightly loose and was bouncing. The other time was definitely the tappets closing up.
Of course, the obvious possibility looks like some partial carburettor blockage.
When I first got my car going it wouldn't go to full revs in a nice gradual way. I can't tell you exactly what was wrong in the carb, which had already been thoroughly cleaned and rebuilt, but a complete stripdown and a fast simmer in a pan of water did the trick.
Just swapping the carb seems a good idea in this case and it would put an end to a wide range of possible causes.
 

Vitesse

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I've had this before, you literally have to feather the throttle and keep the revs low, too much and it will stall and konk out. But would start ok and tick over but soon as you try and rev it, it tries to die again. I am sure it was tappets as Peter said but it was a long time ago it last happened so I could be wrong.

It does seem a bit of a trait of a 500, when you put into winter hibernation running sweet as a nut, take it out again a few months later it seems to have miraculously self adjusted everything by itself.:confused:
 
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Franko500

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I had a days holiday today and thought I would swap the carb over.
I have rebuilt a 28IMB from a collection of carbs using all the best bits.
The carb on Franko was a polish 28SIA with the electronic anti run on valve (that didn't work). Tony supplied me with a valve that worked but I couldn't get the engine to stay running so there must have been a problem with the jet sizes.
I kept having issues at tick over after a run and thought best thing to do was swap it for a standard model.
With everything swapped over which only took 10 minutes, the little bugger would not start. Checked the float bowl - fuel in there!
Poured a little fuel down the carb venture, still wouldn't start. Removed the dizzy cap, points gap looked ok. Cap back on, and hey presto he jumped into life. After a little warming up I adjusted the mixture and idle speed to a reasonable amount and left him running - all ok.
Took him for a little drive and he performed quite nicely with no issues when idling or pulling away.
I pulled up into the garage with the lights on, left him running for a while and then "chug, chug chug" and he stalled.
He wouldn't start again. Checked the fuel filter and there was no fuel coming through. pipe off, turned him over and fuel came out. pipe back on and vroom! Started and ran ok, ticked over, but the fuel is very low in the filter.
Now I have a new pump and the petrol tank cap is free and breathing.
So is this possibly due to the set up of the pump? could it be the thickness of the gaskets are incorrect and causing the pump not to fully operate? any suggestions please?
 

Vitesse

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Sean do you have the fuel pump you can take apart or the sealed one? If the former could be worth while making sure the diaphragm inside is ok.

Fuel filters seem to have a bit of a mind of their own. I have seen mine on tickover with nothing in it but running fine? Most times it is 3/4 full and bubbling away, it very rarely seems to be full up, I would imagine you would only ever see that whilst driving along, which would be pretty difficult.

Didn't you have a similar problem before?
 
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Franko500

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Its a brand new pump which can be taken apart.
I too have seen it run very low and full up with no issues.


Thinking about it I may have to check the dizzy out as I am a little concerned why it only started up straight after I removed/refitted the dizzy cap.
I think I came across a similar problem with the mini's. The engine runs fine under load but on tick over its like it just doesn't pull the spark over enough.


Better do a full once over. valve clearances, timing, points, plugs & connections.
Worst ways could look at a 123 dizzy and electric fuel pump.
 

Vitesse

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Its a brand new pump which can be taken apart.
I too have seen it run very low and full up with no issues.


Thinking about it I may have to check the dizzy out as I am a little concerned why it only started up straight after I removed/refitted the dizzy cap.
I think I came across a similar problem with the mini's. The engine runs fine under load but on tick over its like it just doesn't pull the spark over enough.


Better do a full once over. valve clearances, timing, points, plugs & connections.
Worst ways could look at a 123 dizzy and electric fuel pump.

I think when people see this type of issue, everyone immediately thinks fuel supply issue for obvious reasons but in reality it is always turns out to be something else. I know for a fact I have been down that path as I have a spare brand new fuel pump sitting in the garage but in 20 years of ownership I haven't actually had problems with fuel supply other than the obvious dirty carb.

The problem you had a few weeks back with being unable to rev, the more I think about it I am sure it was valve clearances, so as you said go back to basics and give everything a once over.
 
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I didn't keep the 500 long enough to give a cast iron recommendation, however, in setting it up and using it, the factory magneti ignition system off the later 126's was a breeze.

No issues whatsoever on tick over or operation. Used with a 28 carb in my case, on a 660cc engine.

3840c2ac78da16623904ce33373827dd_zpse6jf8qqw.jpg


20c740fcfcc2dcca4000695891caa947_zps07bxplr2.jpg


Cheers, Steve
 
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Franko500

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Today I had a quick check of the tappet clearances. Straight off I found that with the engine very cold I could not fit the feeler gauges in either valve clearance.
eek.gif

So adjusted them to 0.020 for the inlet and 0.025 for the exhaust.
He started straight away without any hesitation.
Now I know a few weeks before my last drive before the winter I had re-torqued the head and reset the clearances. So in a short space of time the clearances had closed up. Is this normal?
I must admit the engine sounded a little noisier than usual. I then took him for a good drive, stopped a few times and he ticked over nicely. There was no sudden stalling.
Pulled up at home and just went to put him into reverse to go on the drive and he stalled. Possibly too low tick over. He started straight away. a little more revs and parked up in the garage. Adjusted the tick over up a little and everything seems ok.
The only other issue I have is if you just blip the throttle there is a distinct flat spot before it revs up. Also there is only a very small amount of mixture adjustment between running and stalling. I might check the clearances again when cold. I also still need to check the timing and points.
 

Vitesse

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I think I said in a previous post that they seem to automatically adjust themselves in winter hibernation:confused:

Whether it is the fact that it has been sitting there all winter in a cold garage and all the metal has contracted because of the cold, then all of a sudden a few months later we pitch up and start the engine, everything is going expand and close up the gaps once it warms up. It's the only logical explanation I can think of?
 
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Franko500

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Hmm, I like the logic. But surely this can't happen every winter unless you change the head gasket each year. I better order some spare rocker cover gaskets for the future
 

Vitesse

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Hmm, I like the logic. But surely this can't happen every winter unless you change the head gasket each year. I better order some spare rocker cover gaskets for the future

I think the moral of the story is to check everything after the initial winter hibernation startup as it certainly seems to do it every winter for me. I am just as guilty, don't get me wrong. I just reuse the rocker gaskets, so long as they haven't been over tightened they should be fine.
 

fiat500

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It's the only logical explanation I can think of?

Ooh....I think I could come up with an alternative one.:D
Other ways that the valves automatically adjust themselves are available!:D
 
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Hobo1960

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Beautiful car and first class restoration. I'm a new member of the forum and soon to be owner of a 500F which will be sharing garage space with my 1970 Alfa 1750GTV.

I've been reading through the posts that you've made about Franko, particularly the carburettor and fuel issues. In a recent post you said that you'd adjusted the carb and were now suffering with a noticeable flat spot coming off idle. I've no experience of 500 carbs, but have rebuilt Weber DCOE 40's. The flat spot coming off idle usually indicates that the idle adjustment isn't correct. If the throttle has been set open too wide there won't be enough of the transition drilling (progression drilling) left to provide sufficient fuel for the transition from idle to higher speeds. This is what causes the flat spot. I would check the float level of the carb, as an incorrect float level could cause some of the problems that you've been experiencing. I use metric drills to set the float height. They're much more accurate than a ruler. I would then reset the idle and mixture. The idle screw should only be screwed in a small amount just to expose a small part of the transition drilling. The main adjustment should be done with the mixture screw. If the adjustment's been carried out correctly you should have a smooth transition from idle. I would also check that you've got a good earth between the distributor and engine. I had intermittent problems on my Alfa caused by a new oil 'O' ring on the distributor that caused a bad earth. I ended up running a separate earth lead from the distributor mounting bolt to the engine block. The fun(?) of running Italian classic cars, but their little quirks give them an almost human personality.

Good luck
Howard
 
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Franko500

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Thanks Howard and welcome to the forum.
I have been through everything today and found one slight problem - my eyesight!
I found out I had been using metric values for the valve clearances. Only problem was I have an imperial feeler gauge![emoji23]
So that has cured my recently noticed valve clatter and also made it run a lot smoother and has done away with the flat spot.
Now you have a point about the mixture/idle set up.
My idle adjustment is almost to its maximum as its the only way I can keep it ticking over no matter how much I adjust the mixture. Maybe this is down to jet size?
Also I have set my timing to 10 deg (static) but noticed there is play in the rotor arm on its spindle. What's worse is I am using one which is over 20yrs old as the 2 new ones I own have even more play. Now this could make a fair difference to the timing.
It has just been ticking over nicely for a good 25 minutes then just stopped. So I haven't found the real problem yet[emoji23]
 
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