Carb issues Vitesse Mk2 with CDSE carbs

[Paul H]

Hi Aidan. Pretty sure she id running rich.will check the plugs tomorrow.previously she was running weak and i think i over compensated

Regards

Paul

[Paul H]

Hi all back again with tuning my CDSE carbs for my Vitesse MK2 - Just got back from a 40 mile run and checked the plugs and all 6 are too white for my liking so tried to richen the mixture using the allen key , and only got a 1/4 turn clockwise on both carbs before hitting the limit stop so cant richen any further - Does the ignition timing affect mixture ???

 

If not the only logical thing I can think of lowering the fixed jets - If this practice is acceptable ( they are currently set at 100 thou below the base line ) I was going to reset them them at 110 thou.

 

Any other solutions or where to go next 

 

Regards

 

Paul 

[Pete Lewis]

dont remember but are you running on  pancakes which will over lean    or std air box and  paper filters

you can richen base settings with a thicker damper spring or change the diaphragm ring for a heavier one   both of these richen across the needle range

dropping the jet is a bit drastic ... its best to find why before you alter to much.

 

the temp compensators are SHUT ??

 

timing does affect what colour you burn fuel and affects its combustion  temperature , retard hots up  advanced is cooler

 

 

Pete

[Paul H]

dont remember but are you running on  pancakes which will over lean    or std air box and  paper filters

you can richen base settings with a thicker damper spring or change the diaphragm ring for a heavier one   both of these richen across the needle range

dropping the jet is a bit drastic ... its best to find why before you alter to much.

 

the temp compensators are SHUT ??

 

timing does affect what colour you burn fuel and affects its combustion  temperature , retard hots up  advanced is cooler

 

 

Pete

Hi Pete running a standard airbox with paper filters. Temp compensators are locked off - The only unorthodox thing ive done is to add double gaskets and wellseal to the float chambers - no leaks so far . Without Wellseal the float chambers leaked and float height is 17mm - Best to try damper spring - how are these rated ??

 

Paul 

[Paul H]

I have rubber tubing to fit the standard airbox - which are not fitted yet - Would adding these affect the mixture ?

 

Paul 

[Pete Lewis]

Should have remembered, must try harder !,,

hoses not overly but they help collect cooler from the front and not hot air from behind the rad.

 

Damper springs from memory come made in 1mm std or 1.5mm section wire

 

hope you are using engine oil in the dampers thin oil makes acceleration weak mixtures

 

pete

[Paul H]

20/50 used in dampers . Can I try a washer on top of spring to add weight ?

 

Lastly got a 50 mile trip planned this Friday . Should this be put off till the mixture is sorted ?

 

Paul

[Pete Lewis]

Dont add weight on top of spring but on top of piston diaphragm ring

 

if you feel like buying one there are about 3 different clamp ring thickness weights

 

add to the top of the spring wont do much but will restrict full opening /rise of the piston

 

if you lower the jet do check it doenst leach fuel ,

 

may be a needle change , but there are not many alternatives in biased needles about

 

pete

[Paul H]

Here is a pic of the plugs after 10 mile run - I had a 1/4 turn left to richen + added a penny washer to fit over damper tube - Will the penny washer be helping to richen ?  

The plug colour is going in the right direction plus needed to adjust tick over as it had climbed from 1000 revs to 1200 revs 

Would retarding timing help ?

Finally is the colour ok as if not I will have to drop the fixed jets as I cant adjust further 

Thanks in advance 

Paul 

[Pete Lewis]

they look reasonable to me 

        expect any choke sooting to take  a good few miles to burn clean and if accelerating you get a rich mixture 

 its best to pop a plug after a long steady cruise at 50mph for 20 minutes , then have a look 

any drive around town will start to soot up every time you open the throttles to accelerate ,  a good steady light foot cruise ,will show the best weaken result

make sure the washer you added does not obstruct the holes in the bottom of the air  piston.

 

Pete

[Qu1ckn1ck]

Hi Paul,

I have some NOS float bowls that fit the 150CDSE carbs.  They are the type that have a solid bottom without the brass plug, the fitting screw length might vary from yours.  I could take them to Duxford if you think they might solve your problem.

Nick

 

[Paul H]

50 minutes ago, Qu1ckn1ck said:

Hi Paul,

I have some NOS float bowls that fit the 150CDSE carbs.  They are the type that have a solid bottom without the brass plug, the fitting screw length might vary from yours.  I could take them to Duxford if you think they might solve your problem.

Nick

 

Hi Nick - Ive sorted the float bowl issue - Its a bit Heath Robinson though 2 gaskets + Wellseal  and currently no leaks - Hopefully sorted - As to mixture Im going to measure the range for the needle - Divide this measurement by 2 and drop the fixed jets by this amount 

Thanks 

Paul