One white plug

Maxbou92 wrote:

Im from Canada, Quebec.. so how we change plungers? And what kind of needle should I get ?

I believe "Zed1015" normally refurbs your own plungers with new seals and sends them back to you, but sending them to the UK from Quebec and back again would take a little while. Still I guess it won't be long before the winter sets in for you so that may not be an issue ?

Thank youu, I will wait for some replies for the dynojet needles!! For the plungers, how much it can cost me to ship all my carburetor?! I am afraid a bit to send these carbs far away like that!!!! They are hard to find here hihi 😉

Maxbou92 wrote:

Thank youu, I will wait for some replies for the dynojet needles!! For the plungers, how much it can cost me to ship all my carburetor?! I am afraid a bit to send these carbs far away like that!!!! They are hard to find here hihi 😉

You don't need to send the carbs, just the plungers (Zeds Ebay add below)



 

What is the symptoms of bad plungers? My carb were like brand new when I bought them.. so I dont know if they are good or not

Maxbou92 wrote:

What is the symptoms of bad plungers? My carb were like brand new when I bought them.. so I dont know if they are good or not

If the seals are worn or hardened (likely after 45 years) then a small amount of fuel will trickle into the intake causing a "rich" condition tht you won't be able to dial out with the mixture screws

Maxbou92 wrote:

For the plungers, how much it can cost me to ship all my carburetor?! I am afraid a bit to send these carbs far away like that!!!! They are hard to find here hihi 😉

You don't send all the carbs.
Just the bare plungers with springs etc removed as in the pic.
I replace the old worn and leaking seal with ethanol resistant viton.
I have done hundreds worldwide and it usually only takes about a week to 10 days on average each way to and from Canada, USA etc.
Here's my email -   zed.1015@yahoo.co.uk    -  if you want more details on price and how and where to send etc.
Price direct is cheaper than Ebay with their fees etc. 

I would hold off on a Dyno Jet, all its going to do is make the carbs richer (darken the plugs more)
The needles on those kits are very rich compared to stock needles. If your already running the air corrector jets per Zed1015 this would be a step backwards as that one plug is very close to being jetted properly.

A step in the correct direction is to refurbish the choke plunger seals. This is often a part that builders neglect to change but is vital to correct tuning.

Thank you guys!! I will check for those plungers this winter!!  If I could correct the 3000-4000 rpm, the bike will awesome from start to end 

Here is a example of "Dyno-Jet" needle for a CVK carb :





Stock needle has no adjustment but can be adjusted "leaner" by stacking washers under the heads. You can see how much thinner = richer the Dyno-Jet needle is.

Generally you should only try to fix one issue at a time when trying to tune carb problems, it is hard to track what fixed the issue when changing multiple tuning parameters. Get the choke plungers fixed then see how it runs, move on to needles if it does not solve the 3-4K RPM issue.

Yes!! Before I had CV34 with washers for these needle!! My dyno guys say that is the pod filter that causing it, because after 4000 rpm the AFR is correct!! But why I just have one good spark plug at idle ?!! Very weird!! You can look my dyno sheet 

Maxbou92 wrote:

Yes!! Before I had CV34 with washers for these needle!! My dyno guys say that is the pod filter that causing it, because after 4000 rpm the AFR is correct!! But why I just have one good spark plug at idle ?!! Very weird!! You can look my dyno sheet 

This is why I suggested the plungers may be an issue (1 good one ?)

At 3000-4000 RPM a bunch of different things are happening in the carbs and engine. Your going from pilot (idle) circuit to the needle circuit plus the ignition timing is going to full advance. At that same time the butterflys (CV carbs) are wide open but the slide may only be partially up depending on vacuum.

Transitions like this are hard to tune in general, going slightly lean for a very short duration at low RPM is not going to hurt the engine especially if the main jet is correct. I have seen dips like that in AFR graphs before, not uncommon at all. I would concentrate more on getting the plugs to burn tan than black instead of a small AFR blip.

There is a limited tune up for gasoline carbs and its very narrow, not too many changes can be made unlike electronic fuel injection.