GS1000G vibration

[mkles]

Hey GSer's

Picked up my 2nd gs last august and just finished it this year with a huge amount of help from all the knowledge on this site. Completed all the recommended upgrades and service. The bike runs great, charging well, idles at 1000 rpm. It is a 1980 GS1000G. The only problem I have is that there is a increased amount of vibration at 3000 rpm and goes away around 4000 rpm, it does not matter if it is in neutral or in gear. It runs through the handlebars and tank and seat. The only thing I can come up with is when it is going from the slow system to the main system in the carbs something is not right. Is this normal, My 1982 GS650G does not do this, It smooth from 1000 rpm all the way to full throttle. Any help would be much appreciated, the bike has 14,000 miles on it.

Thanks

[Dogma]

I'm going to say that's not normal. I'd love to recommend a troubleshooting method (other than checking all the stuff you know is right), but I'm never had to solve that particular problem.

[Nessism]

Sounds normal. You may want to vacuum sync the carbs if you haven't done it lately. Can't hurt anyway.

[salty_monk]

Make sure the engine mounts are tight. Sync the carbs. Make sure the tank & seat have all their rubbers in place (fresh ones). Add some weight or a bar snake to the handlebars.

[mkles]

Thanks guys,
New intake orings, valve clearances are between .0025 and .003 1000ths of an inch, cleaned and synced carbs at 1500 rpm, slightly less vacuum reading on # 2 & 3 cylinders. I might have a small air leak cause the idle stop screw is turned all the way out and it will not idle below 1000 rpm when warm. I might resync in the spring and maybe new intake boots even though they looked fine, very soft and no cracks. just thought I would ask for input.