Carb clean and rebuild - to jet or not to jet?

[philosopheriam]

Folks,

I'm in the middle of cleaning/rebuilding the VM26's on a recently purchased 1978 GS1000.

My plan for the bike is a complete restoration, but for now, I want to get the engine running to check its overall health.

Unfortunately, the carbs were beyond disgusting - I've seen gummed up carbs before, but these took the cake... So, one at a time, I'm completely disassembling the carbs and cleaning them.

The question is:

The eventual plan for the bike is to keep the stock air cleaner with a K&N filter and to install a Vance & Hines 4 into 1 exhaust system.

Since I'm cleaning the carbs and already have them apart, would you folks suggest rejetting the carbs for these mods while I'm in there - iI understand that rejetting them might cause the bike to run rich in it's stock form, but I have no plan on riding the bike until it is totally finished. So, even if the carbs are jetted rich, I can still get the engine to run so I can check the engine? Good idea?

If so, what jet sizes/needle positions would you recommend?

Also, I understand that there are no "factory" numbers for the number of turns out on the pilot air and pilot fuel screws. However, for an initial setting, what would you folks recommend setting them at?

Your help is greatly appreciated!

[Agemax]

leave the jets as they are for now. it will still run ok even with the k&n filter and 4into1 but you wont be able to sort the jetting out correctly until you are actually riding it

[Steve]

If so, what jet sizes/needle positions would you recommend?

For the stock bike, you would obviously use the stock jetting and needle positions.

Also, I understand that there are no "factory" numbers for the number of turns out on the pilot air and pilot fuel screws. However, for an initial setting, what would you folks recommend setting them at?

For stock intake and exhaust, the fuel screws (the ones on the bottom) should be 3/4 to 7/8 turn out from lightly seated. The air screws (the ones on the sides) should be double that. When you install the pipe, the fuel screws might need to go to 1 to 1 1/4 turns, again, start with the air screws double that. When the bike is warmed up, slowly adjust the air acrews for the best idle speed.

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[philosopheriam]

Thanks a bunch - I couldn't rely on the settings that the screws were currently set at because it was very obvious someone had been screwing with the adjustments to get the bike to run. Instead of cleaning the carbs, why not just mess with the screws, right?

I grabbed this pic from the GS1000 manual - these are the stock jet sizes of the carbs, correct?

However, the stock needle position is #3 (from the top), correct?

[Big T]

Yes

and , Yes