No power, poor tick over , vitesse mk2

[Paul H]

Vitesse was doing well , refurb CDSE carbs speced for vitesse mk2 , no issues , plenty of power through the range , started first time . Then I ran out of fuel , no issues initially then out on a run it's as if somebody's flicked a switch and now no power at all and lumpy tickover, won't go up a hill , have to drop down gears and crawl at 10mph which was embarrassing !!!!

 

Back to basics and checked compression with a range of 165 to 175 , most of the cylinders were 170 , is this ok . Compression test was with out plugs and throttle open and started for 10 secs. Engine had been run for 10 mins prior

 

Then checked the timing , there are 2 white marks either side of tdc and the strobe is showing slightly to the left of the left hand mark . Hope this makes sense . Is this the cause of the lack of power . Where should the strobe hit ?

 

If this isn't the cause will start checking the carbs for contamination, fuel is getting through as just added a disposable filter after the pump and fuel is clearly visible, I will also be adding one before the pump. Are there any obvious pointers to check on the carbs for contamination ?

 

The disy cap has a small chunk missing on the rim, will be changing as water could get in, could this be the cause, would I need a new rotor as well, the previous owner had converted to electronic , not sure which make

Any assistance welcome

Regards

Paul

[dougbgt6]

Have you checked your carb diaphragms? These are exactly the symptoms if one or both are punctured.

[Paul H]

Have you checked your carb diaphragms? These are exactly the symptoms if one or both are punctured.

Hi thanks for input , haven't checked the carbs yet though will start tomorrow

Regards

Paul

[Pete Lewis]

make sure you line them up on refit there is a lug on the diaphragm that sits in a  slot on the body,  

 

if they are all baggy and distorted wash them in petrol and they revert to as new size.

 

could be tied to running out and you have sucked up some debris or disturbed some on refilling, unlikely on a Vit or Herald as th suction pipe in the tank doesnt suck down to the bottom.  (well it shouldnt)

 

so you may have debris blocking the back of the  float needle .

 

the damper rim on the crank is marked for top dead centre and increments shown before and after

  find the bigger mark is tdc and time it to 10deg before top dead ,    

 

you dont need a strobe , a small pea bulb from coil dizzy side to earth it will light when the electronic switches   just the same as with old points