Carb Rebuild Story 1999 I/S (long read)

[1fastbob]

I have been working on trying to get my new to me 1999 Valkyrie Interstate running properly for about 10 months now.  As some of you already know I picked up a used 99 I/S late last summer for a great price, but the only catch was that it had been setting in someone’s garage un-ridden and un-started for maybe as long as 3 years.  We trailered the bike home and I removed the carbs, cleaned the jets then reinstalled the carbs only to remove them again the same day to repair a stuck fuel supply needle.  After reinstalling the carbs the second time the I/S fired right up and seemed to run pretty well.  During the carb cleaning I installed new spark plugs and changed all the fluids (except the battery electrolyte).Since I had no prior experience with Valkyries I rode it over to Bobz BikZ in Kingman, Kansas to have salesman Steve (a Valkyrie owner ) and Bob (owner of Bobz Bikz) take my I/S for a test ride.  They both told me it ran pretty well, but was just a little boggy in the low and mid range.  I was NOT satisfied the way it ran.  It slobbered and burbled at steady throttle at 2000 to 3000 rpm and seemed to run fine at wide open throttle.  It also seemed to miss at idle and applying the choke made it run better at the lower rpms.I did a little more diagnostic work and found with an infrared digital thermometer that the #6 exhaust pipe was 50 degrees cooler at idle than the rest of the cylinders (195 vs 245 to 250).  I decided that certainly I still must have some blockage in the #6 slow jet. I ran lots of Seafoam and Techron through it and it never got better even after 1,000 miles.  I also tried Berrymans B12 and it still wasn’t just right. Recently (within the last 2 weeks) I ordered a complete set of jets (size 100 mains and 38 slows) from Chaparral and after they finally arrived I deceided it was time to remove the carbs again, remove them from the carb rack completely disassemble them, clean them , install all new o rings (thanks to Redeye Tech.) and install the new jets (I set the pilots out 1 ½ turns and I am at 1880 feet above sea level). Before carb removal  I ran a dry compression test and the results were great as all cylinders were between 138 and 140. I then removed and rebuilt the carbs , did a partial desmog ,reassembled and installed some more new NGK plugs.  She fired right up and wow when these machines are running right they are smooth and powerful.  I took a 45 mile ride yesterday evening and this thing is a transformed machine. I wanted to thank this forum for providing the necessary information that allowed me to do this successfully.  I also want to thank the person that suggested to buy new jets and NOT attempt cleaning the old ones (can’t remember his name).  When I first read that I though what a numb nuts and what a waste of money, but I ended up being the numb nut. Do NOT try to clean jets as you can’t get them completely clean.  Follow this suggestion if you have carb problems and it will save you lots of time.

Thanks again

Bob with a properly running I/S

[9Ball]

my guess is that it was me that made the recommendation to replace rather than clean.  I've always been an advocate...

...and yes, sometimes I'm a numb nut

[1fastbob]

I have also been known to be a  "dootyhead" once or twice also .  Replacing those jets was Great advice, wish I would have taken it the first time.

Thanks

Bob

[alph]

were did you get the jets?  i'm currently working on an '84 yamaha, did the same thing, cleaned out the carbs......  yeah, yeah, yeah, what ever......  maybe i'll try some new jets......

al.

[1fastbob]

You might try Sudco, I got mine at Chaparral Motorsports.....paid $18.00 to get them in 2 days and it took 8 days.  I was NOT impressed and will not buy from them in the future.  A very strong magnifying glass or eye loupe is very helpful for looking for dirt in the jets.

[Pete]

Great story Bob, happy to hear that you got it running right.

Carb cleaning is not rocket science, but it must be brain surgery clean.

Sometime replacing parts is the simple and easy way to get it recovered, especially today.

What passes for gas today leaves a very hard to clean solid residue the is a b-t-h to get out and many folks will mess up the jets trying to clean them.

As you have discovered nothing runs as well as a properly cleaned serviced set of carbs.
Chemical cleaning sometimes helps, but what you did always works better.

Have fun.

[1fastbob]

Great story Bob, happy to hear that you got it running right.

Carb cleaning is not rocket science, but it must be brain surgery clean.

Sometime replacing parts is the simple and easy way to get it recovered, especially today.

What passes for gas today leaves a very hard to clean solid residue the is a b-t-h to get out and many folks will mess up the jets trying to clean them.

As you have discovered nothing runs as well as a properly cleaned serviced set of carbs.
Chemical cleaning sometimes helps, but what you did always works better.

Have fun.

Pete, don't forget the FUN factor involved in removing and reinstalling the carbs and the air box!

Thanks

Bob