Running hot/lean on cylinder 1 and 4

[Guillermo.engineering]

I'm in need of some advice.
I have a 83' gs650gt which I have been restoring. The bike hase all fresh filters, sprak plugs and fluids and the carbs were cleaned. I changed out the original mufflers for some more open after market ones but retaining the stock 4 into 2 headers.
After the installation of new intake manifolds, a new oem air filter element I wanted to jet the bike since it was running very lean. I am running stock jets and needle settings only all fuel mixture screws are out 2 turns at the moment. The bike runs very nice but has some popping from the exhaust when closing the throttle and sometimes when hot when its running at idle.
There are no dips in power, returns to idle as it should etc.
My only problem is that when i pull the spark plugs plug from cylinder 1 and 4 seem to be too white while plugs 2 and 3 are nice mocca brown to grey.
This seems weird to me while the bike drives great and it sounds like the carbs are in sync (haven't synced yet)

So my question to you is: is this normall on the gs and thus should i compensate by turning fuel screw on carb 1 and 4 out some more or do i need to further investigate valve clearences, compression and the ignition coils ?

 

[Big T]

You do know that the fuel mixture screw only affects idle and slightly above?

If you haven't adjusted your valves, or done all of the other maintenance, you're just spinning your wheels

 

[tom203]

Your new less restricted mufflers might be flowing different on outer cylinders....you could try backing out those mixture screws another half turn, but it would be best to get to carb sync stage soon.

 

[Guillermo.engineering]

yes i am aware how the cv carb works and which adjustments do what. but since all carbs are adjusted in the same way it would be rather strange that cylinder 1 and 4 are showing signs of running hotter than 2 and 3. I just pulled the carbs to check if they are clean and to make sure the rubber boots from the airbox are sealing propperly. I noticed the fuel adjustment screws didn't have any sort of O ring to seal them, are there supposed to be O rings there? I am going to check valve adjustments and then do a carb vsync.

 

[tom203]

The mixture screw needs a o-ring to accompany the spring and washer setup....

 

[Guillermo.engineering]

little update, i just checked valve clearences. I need to get some new feeler gauge as mine only has 0,05 and 0,10. it needs between 0,03 and 0,08 but what I can see now is that most valves are a little tight especcially the exhaust valves for cylinder 1 and 4. so after fixing this i will be syncing my carbs.
side note, the fuelscrew did have the rubber sealings and all the carbs are still clean as a whistle.