I think I know what's wrong

[Houdini]

...but I thought I'd check with y'all.

First off I've been cheating on my Interstate with a younger thinner model for a while now.  I start the IS at least once a month but haven't really ridden her much over the last 1.5 years.  I had to ride her recently due to maintenance on my Standard and she runs terrible off of idle, stumbles and requires a lot of gas and clutch to get going.  I've ran a couple of tanks of premium and three cans of SeaFoam with no improvement.

Carbs?  Low speed jets plugged?  And other easier issues I should check first?

[Red Diamond]

Chuck, last time an issue like yours was encountered was on a friends I/S. We poured in a can of B-12 into a full tank, rode it about 150 miles. When got back it was running fine, he was off of it because of a kidney transplant, almost a year and a half.

[Valkpilot]

...but I thought I'd check with y'all.

First off I've been cheating on my Interstate with a younger thinner model for a while now.  I start the IS at least once a month but haven't really ridden her much over the last 1.5 years.  I had to ride her recently due to maintenance on my Standard and she runs terrible off of idle, stumbles and requires a lot of gas and clutch to get going.  I've ran a couple of tanks of premium and three cans of SeaFoam with no improvement.

Carbs?  Low speed jets plugged?  And other easier issues I should check first?

Chuck, I'm not convinced that SeaFoam is the best cleaner to use.  I think Techron actually cleans better, but doesn't have the same stabilizing properties of SeaFoam.  I think B12 is somewhere in the middle.

Now, what I really think, is that using a combination of all three by running it through in strong concentrations in succession (tank, or partial tank, of 1, then the next, then the next) will do better than just multiple tanks of any one of them.

Premium gas is no particular benefit to the process, so just use the grade of gas you normally use.

Last ditch effort before breaking down the carbs: Get some YamaLube Carb Dip.  Take off the tank. Drain the carb bowls and rig a way to get the carb dip into the fuel line.  Crank the engine while pouring the Yamalube into the fuel line.  Let it sit overnight.  Repeat.

Disco used this method on some pretty badly plugged carbs and was able to clear them without having to rebuild them.

[Mr.BubblesVRCCDS0008]

fixing to pull carbs on my new to interstate same thing . Only sat for about 45 days but number 5 carb is plugged tight. Tried B-12 full can then full can techron drove over 200 miles cylinder still dead at idle comes in over 3k on tach. Used a temp gun on exhaust to find which carb was plugged gonna clean or replace all jets.

[BnB Tom]

  My personal thought is that you are comparing your older, slower, heavier IS to your younger, quicker, lighter Valk. 

  Sorta like getting out of your Corvette and into your SUV. 

[Houdini]

  My personal thought is that you are comparing your older, slower, heavier IS to your younger, quicker, lighter Valk. 

  Sorta like getting out of your Corvette and into your SUV. 

Not quite.  The IS barely idles and will stall on take-off if I don't feather the clutch and rev 2500 RPM's or better.  She will also stall if I leave her idling without the choke for more than 20 - 30 seconds. 

I dumped a can on B12 in half a tank last night and rode her about 25 miles, I plan on taking her for a longer ride today time permitting.

I need to have her running right by the TX ride in since I plan on riding her down.

[Joevalk]

Unless you are riding around in 5th gear doing 20-30mph, you are wasting your time. Slow jet don't work above a certain rpm. Pull carbs and clean the jets would be easiest

[Houdini]

Chuck, last time an issue like yours was encountered was on a friends I/S. We poured in a can of B-12 into a full tank, rode it about 150 miles. When got back it was running fine

Good suggestion Eli, I used Berryman's up until I joined the VRCC and then started using Seafoam. I ran about 80 miles today across 380 from McKinney to Denton and back which has a lot of red lights to deal with so I did use my slow jets.  She idles on her own now and has improved about 50% on takeoff.  Once I completely empty the tank I'll put the second can of B12 in and maybe followup with a can of Techron and I think she'll be good to go.

Thanks everyone.

[Houdini]

Hesitation!

What hesitation?

Stumble?

Nope!

I put two cans of B12 in a full tank, wrapped a bungy around the throttle to apply just enough pressure to hold the throttle in place, started her up and twisted the throttle until she started to stumble.  I put a fan in front of the radiator and let the bike sit there running for about 25 - 30 minutes. 

She ran like a champ commuting to work today; maybe I'll rebuild the carbs next year.   

[Six Guns]

      

[legender]

Congrats on the quick and easy fix.
Surprised I haven't seen you around town... 

[Yfx4]

I live in Melissa. Once I get mine fixed we should meet up!

[Disco]

Great report, Chuck!