General 750 engine - timing - pinking

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General 750 engine - timing - pinking

gb1ker

Hey, I get a title!
Joined
Feb 19, 2007
Messages
34
Points
8
Location
Surrey UK
Hello all, been using my little Firefly for a few weeks now, mixed feelings about it at present. The 750 engine seems reeeeeeally slow, I thought it would be nippier in a little kit car, the throttle control is very heavy despite the cable seeming fine - I took it off and lubed it but still the same. Clutch is also very heavy feeling - strong spring on the clutch lever at the engine end?? Cable is good and not binding.
Getting a slight pinking, which way do I rotate the distributer to retard the timing slightly? Don't all reply with different directions! :D
cheers folks
 
Hello all, been using my little Firefly for a few weeks now, mixed feelings about it at present. The 750 engine seems reeeeeeally slow, I thought it would be nippier in a little kit car, the throttle control is very heavy despite the cable seeming fine - I took it off and lubed it but still the same. Clutch is also very heavy feeling - strong spring on the clutch lever at the engine end?? Cable is good and not binding.
Getting a slight pinking, which way do I rotate the distributer to retard the timing slightly? Don't all reply with different directions! :D
cheers folks

The firefly kitcar might be small but it isn't light. It wieghs more than a standard panda due to the wieght of the chasis I belive. You realy need a 1242:devil:
 
And what should the correct timing setting be?
My 750 idles at 15degrees BTDC and doesnt change when you plug in or un-plug the vacuum pipe? Is that normal? Is my vacuum advance dead?:confused:
Ta:)
 
Im sure 15 degrees is OK for the FIRE lumps with vacuum connected. The easy way to tell if your vac is knackered is to remove pipe from car, remove dissy cap and rotar arm and suck on the pipe, your base plate should move. If it doesnt then its ether seized up or more likely the vac advance is broken.
To time it static its 2 degrees, try that and see what happens.
 
Is my vacuum advance dead?:confused:
Ta:)
Yes, it is.

You don't need to dismantle to watch bits move - if you can suck through it without creating a vacuum it's popped.

When popped it gives you a lean mixture, which doesn't help performance.
 
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Hmmm, checked out timing, can't seem to stop pinking. Vacuum advance appears fine, I thought/hoped this would be the culprit. Points look fine, gap ok. I checked the plugs, they are very light coloured indicative I think, of lean and/or hot running? The engine seems very underpowered, barely goes over 65mph, def not right methinks! I've tried adjusting the mixture screw, to no avail - screw it all the way in and the engine will die, screw it all the way out to the end and it makes no difference to smoothness (or lack of! real lumpy!) of idle and no difference to performance.
My current conclusion therefore, is that it's running too lean but I don't know why! No sign of any leaks....did I read somewhere on this forum once about a potential prob with the carb that can cause lean running? I'm at a bit of a loss, am I overlooking something or has anyone got a brilliant suggestion(s)? :worship: (n) :confused: It's doing me heed in a bit! :p
 
change the points, they can look fine but the plastic cam that rubs on the dissy shaft wears and they then dont adjust properly, even though they look fine.
I would screw your idle in fully then out 1 1/2 turns and work from there, drive it for 15 or so miles and check the plugs... see what colour they are and go from there. You might have an air leak somewhere but first do the above.
 
Ta, I've bought new set of points - on Ebay so I'll bung em in anyway -got them for less than a fiver, they are £24 in Halfords (not in stock, special order only)! So, the idle screw is an air screw right? Turning it out lets in more air? rather than more petrol. I think I may have it too far out after yesterdays tinkering. Cheers! :eek:
 
Ok, thanks Nuovapanda, your advice has done the trick..mostly! New set of points and car is running soooo much better, pinking noise disappeared completely. Still won't win any standing starts with anything more than a milk float but nice to drive now. :)
Still a slightly lumpy or hunting idle though, not a big prob but I don't know whay that is.....

:worship:
 
Aw, nobody talks to me cos mine's a kit car, if only it was pink........




:p
:D
:)
:cool:
 
Hello there !! Did you have any luck sourcing a hard or soft top please?
Rgds
 
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Aw, nobody talks to me cos mine's a kit car

Its only because we're jealous:D

and you keep asking about the black arts of carbs, points and stuff. I went all electronic about 15 years ago;)

We would love to see it (and you) at one of the shows next year :)idea: you could also pop along to the Ace cafe on the 2 Thursday of each month)

cheers Damon
 
Howdy, never did sort the roof out, I fitted the roof that I was given, which is pretty grotty but just about keeps the rain off me. Lack of time and funds have prevented me tracking down a new roof. It's not ideal for me as I have no garage and to be honest, my 36 mile a day round trip to work is peeing me off as it takes a good hour and a half to get to work, barely 18 miles away :bang: . I may well sell the car and go back to motorbiking, that way I get an hour or two of home life back...and a little more time in bed in the morning!
Anyone want to buy a kit car or swap me a bike? :) Maybe Ebay beckons again......
 
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