Power lose

[vdubkev]

Hi all just wondering if any one can through the light on a prob I had today
Went up to volksworld 120 mile round trip bus didn't miss a beat ,being its first really good run since the full resto
Today went for a small run ,aprox 7 miles in I noticed that it started to chug a bit and wouldn't pick up and with me feathering throttle she came to a stop , checked for any lose leads. Found nothing ! Turn her over and she fired right up and seemed fine so I drove for about another mile and she did the same thing but luckily we got in to car park , still couldn't find any thing visible , so I thought maybe leave her for a bit to cool down ,didn't really seem over hot but still went for a coffee ! Came back ,started again and drove the 8 miles back home without missing a beat,very strange, feel a bit apprehensive of taking her out again so any thoughts and ideas would help
It's a 1641 engine with about 600 miles on it running standard bocar 34 pict carb bosh 009 electronic dizzy with vac advance ,petronix coil ,standard exhaust !
One thing I did notice was when I took the fuel cap off there seemed to be a residual of fuel in the top of the cap!but no hissing of air as thought maybe a vacum might have built up in the tank ,
Kev

 

[thejinx]

Timing?
Are you running a non stock air filter? Carb freezing.

 

[vdubkev]

Standard air filter bud

 

[Trikky2]

Check fuel delivery. Could be a weak pump or a blocked line or filter.

 

[vdubkev]

Checked fuel lines ! Filter ! And striped carb down , small amount of dirt in bottom of carb! Just waiting on rebuild kit for carb b4 testing ! Any other ideas greatly appreciated
Kev

 

[StuF]

If the rough running only happens when the engine is upto temp and you have been driving a while you may have an issue with the coil breaking down and not providing a decent spark
Although it should only do this when warm/hot - if it is the coil at fault it will run just fine when cold and start stuttering and be hard to rev when warm.

 

[vdubkev]

Think I've sorted it
On fuel inlet there's the needle which shuts off fuel when float touches it ! When I took it out the hole had a small bit of dirt in it reducing the hole size ! So I think while I was driving at around 35 to 40 the fuel flow could keep up , but once went over 40 to 50 the flow couldn't keep up ! Hence why it started up straight away after stopping ! Fingers crossed
Thanks for all your help !!
Kev

 

[Trikky2]

Think I've sorted it
On fuel inlet there's the needle which shuts off fuel when float touches it ! When I took it out the hole had a small bit of dirt in it reducing the hole size ! So I think while I was driving at around 35 to 40 the fuel flow could keep up , but once went over 40 to 50 the flow couldn't keep up ! Hence why it started up straight away after stopping ! Fingers crossed
Thanks for all your help !!
Kev

Check the piece of dirt - it may be rubber from the fuel hose.

 

[vdubkev]

Cheers trikky2 I'm going to change the fuel pipe back to the tank