Alex, it's not necessarily how long it can take to jet correctly, it's because you can end up taking the carbs apart several times. I would'nt want to do that during a long trip. On the VM carbs you should synch the carbs with a vacuum tool every time you disturb the needles. A poor manual synch will cause different levels of vacuum between the four cylinders and you'll get different mixtures being burned regardless if you set the jetting right.
Because there are so many variables to consider (equipment/mod's, engine compression, state of engine tune, elevation, etc,) regarding jetting, it can be a lot of trial and error. Lean mixtures can be harder to detect, especially at higher speeds. You could be buzzing along on your trip and not realize your motor's overheating. I would'nt want to see that happen, so I reacted like I did to your roomates comments. He may be a good mechanic, but he does not understand carburetion on these older bikes.
What you did, raising the stock needles 2 positions, is what I would have done also. You should always jet "rich" and work your way back. Your needle is now raised as high as it will go but you may be lucky and find the plugs read good. You may even find that you'll have to lower them a 1/2 position or even a full position. A 1/2 position would be achieved (in your case) by leaving the clip where it is (#5) and placing a jetting spacer on top the clip. A jetting spacer for your carbs is about .022" thick. Of course, always replace the plastic spacers (thick and thin) in the same order. The next step leaner would be removing the jetting spacer and moving the clip to #4. It all depends on how well your pipe/pods flow. You may find the stock needle won't get you the reads you want and in that case you'll have to go to a jet kit.
As for the mains, I would GUESS 4 full sizes up from whatever is stock and go from there. You'll also have to adjust your pilot screws (underneath) out some. I would try a 1/4 to 1/2 turn out (c-c-w) beyond where they are now. Then adjust the side air screws for the highest possible idle and re-set the idle with the idle screwknob. Adjust the side air screws with the bike warmed up and on the centerstand. Get low speed plug reads. If you reach the point that you have to adjust the pilot screws past 3 turns out, you are leaving their range and you'll have to go up a step (2.5) on the pilot jet and re-adjust the pilot screws back and start over. Be sure to do a good vacuum synch. To avoid mixture problems, get the vacuum levels all within 1 cm of each other. I ALSO RECOMMEND replacing the 4 manifold o-rings if they are hardening or have any cracks. Put some hi-temp' bearing grease on them and torque to 6 ft/lb.
Another factor in jetting is the owner. Some of us are just lucky and get the jetting right quickly. Some of us have to trial and error ourselves to death. Also, some of us are just more easily satisfied and don't care if the jetting is "perfect" and run out of patience. If the bike runs "OK" they're happy. So this also is part of "how long" jetting takes some people.
Because there are so many variables to consider (equipment/mod's, engine compression, state of engine tune, elevation, etc,) regarding jetting, it can be a lot of trial and error. Lean mixtures can be harder to detect, especially at higher speeds. You could be buzzing along on your trip and not realize your motor's overheating. I would'nt want to see that happen, so I reacted like I did to your roomates comments. He may be a good mechanic, but he does not understand carburetion on these older bikes.
What you did, raising the stock needles 2 positions, is what I would have done also. You should always jet "rich" and work your way back. Your needle is now raised as high as it will go but you may be lucky and find the plugs read good. You may even find that you'll have to lower them a 1/2 position or even a full position. A 1/2 position would be achieved (in your case) by leaving the clip where it is (#5) and placing a jetting spacer on top the clip. A jetting spacer for your carbs is about .022" thick. Of course, always replace the plastic spacers (thick and thin) in the same order. The next step leaner would be removing the jetting spacer and moving the clip to #4. It all depends on how well your pipe/pods flow. You may find the stock needle won't get you the reads you want and in that case you'll have to go to a jet kit.
As for the mains, I would GUESS 4 full sizes up from whatever is stock and go from there. You'll also have to adjust your pilot screws (underneath) out some. I would try a 1/4 to 1/2 turn out (c-c-w) beyond where they are now. Then adjust the side air screws for the highest possible idle and re-set the idle with the idle screwknob. Adjust the side air screws with the bike warmed up and on the centerstand. Get low speed plug reads. If you reach the point that you have to adjust the pilot screws past 3 turns out, you are leaving their range and you'll have to go up a step (2.5) on the pilot jet and re-adjust the pilot screws back and start over. Be sure to do a good vacuum synch. To avoid mixture problems, get the vacuum levels all within 1 cm of each other. I ALSO RECOMMEND replacing the 4 manifold o-rings if they are hardening or have any cracks. Put some hi-temp' bearing grease on them and torque to 6 ft/lb.
Another factor in jetting is the owner. Some of us are just lucky and get the jetting right quickly. Some of us have to trial and error ourselves to death. Also, some of us are just more easily satisfied and don't care if the jetting is "perfect" and run out of patience. If the bike runs "OK" they're happy. So this also is part of "how long" jetting takes some people.