My new Seca550 - TWINSIES! plus carb questions

Pretty neat, I have had the white one for quite a while now and had plenty of work to do but has been great for MANY miles. Apart from the basics, carb and valve setting it got new chain and sprockets, rebuilt starter motor, rebuilt brake caliper, new fork seals and various other bits. new pipes. took it to the dragway and got 12.6 112mph 1/4 mile! I guess that's pretty standard but I was quite impressed from a 30 yr old midsize bike.
Doesnt need much more yet, tires soon, the petcock sputters somewhat (slight leak) and I believe the throttle shaft seals need replacing - after about 10miles or 15 minutes the idle goes from a good ~1400 to a high ~2200 and it seems to run hotter.
Does that seem like throttleshaft seals? Delayed lean condition only when hot?

ANYHOW I just picked up the matching red one yesterday for a low $400. It's in good shape but wasn't running. Tank's got a good dent on the right and torn seat cover and BIG rust holes in the pipes but otherwise cosmetically nice.
With a thorough carb clean and jumping the broken starter relay i got it to start up and ride! clutches slip like crazy and have yet to check the valves, but there's a unique issue i have I was hoping for maybe some advice on

The bike runs and responds well except idles very high when warmed up. What's especially odd though is if i manually press the throttle shaft down the idle drops to a normal level. Like the return spring isn't returning?

Soon, maybe tonight, i'll take the carbs back out and see if one of the springs isnt on the return tab or something. Or see if I can even get to the synch screws or see those springs with the carbs installed. Either way I mostly just wanted to share the bikes , and i figured i'd tack on the issues i'm seeing to check if someone else with more history has a better idea of the problems

 

Nice pair!

 

When you take the carbs off later check to make sure that the butterfly valves are aligned properly? I had a similar problem.

 

dunno if something was caught bench synch or somthing but #4 was just way off. reset it on the bike and it idles great, waiting on some new parts, chain, forkseals, starter relay, oil filter, clutch pads n new springs. Rode it for a while yesterday, man those clutches are BAD!

 

You might want to read this http://xjbikes.com/Forums/viewtopic/t=29541.html if you're not familiar with the oddities of a 550 clutch.

Oh, and be sure to replace both sprockets lest your new chain wear out prematurely.

 

got the sprockets already yep. had ordered them separately when i did the old one, and then bought a full sprocket/chain combo set when i bought the chain. oops. looks like i was already preparing for second seca fun