My GS850L has not power at 3500 rpm

[Kratzer]

I go above 3500, it pushes me into my seat.

Up to 3500 smooth power.

The engine has old gas going into it, and it never got completely warm.

Valve adjustment?

[tkent02]

Valve adjustment?

Always a good idea, unless you just did it.
Dump the old gas if it smells funny, if not burn it out.
Get the bike good and hot, take it for a real ride.

[DanTheMan]

There is a power curve that occurs between 3500 and 4200 RPM. It feels almost like a turbo kicking in, and it's entirely normal. :-D I love it, reminds me of my old '70 Fiat 850 Spyder after I bored it (.40 over) and put in a 3/4 race cam; this bike came from the factory that way. It will push you back in your seat and give you an appreciation for the way they engineered this engine. The Japanese have been quite adept at adapting good designs and implementing those adaptations to good use.:-D

On Edit, you said "I go above 3500, it pushes me into my seat." , but your post said "has not power"...... huh???

[tone]

I'm guessing he means it has a stutter at 3500 revs but is ok everywhere else :-|

if thats the case it could very well be badly ajusted carbs, depending on the setup & health of the engine it could be stuttering on the changover from primary to main jets, its in the right rev range

more info needed really ! what exhaust is it running ? standard airbox or pods? standard jetting?

if all stock i'd clean carbs, set float heights to stock settings, same with air screws & sync carbs

[Kratzer]

I'm guessing he means it has a stutter at 3500 revs but is ok everywhere else :-|

if thats the case it could very well be badly ajusted carbs, depending on the setup & health of the engine it could be stuttering on the changover from primary to main jets, its in the right rev range

more info needed really ! what exhaust is it running ? standard airbox or pods? standard jetting?

if all stock i'd clean carbs, set float heights to stock settings, same with air screws & sync carbs

Standard airbox and jetting from what I can tell. That makes all the sense in the world about primary v main jets. I didn't know about that. It felt like in a 4 barrell carb, when the primarys are working right, but the secondaries delay kicking on by a little margin.

My plan for today is to get some seafoam and start there. The cars were rebuilt a litte less than 3 years ago, but it sat for one of those years.