CARBS, Help Needed - The Readers Digest version on jet replcement

[Capt7three]

I need to replace my jets, it appears. Startup and idle is fine, acceleration after 3000 rpm is great. It stumbles from the getgo in first gear, and in any gear below that 3000 number. I've done the cleaner soak spa treatment (Seafoam, Techron, Berryman B-12), it is a little better, but not what I want. I'm fine with the stock jets, when they work properly. Does anybody know where, or if, there are stock "jet replacement kits" available? I need float bowl needles and seats, all the jets, and any other hardware (O rings, etc.). I am looking for a one stop shopping adventure = "Here's a kit, please pay the cashier". I am handy with tools, turnin wrenches since I was 8 or 9 (63 now), jet machanic (no pun intended) in the Air Force, FAA A&P, etc., etc.

Also, I have read all of the posts regarding CARBS, and come to the conclusion that sooner, or later, a complete jet replacement will be required, no offence to those who truly believe in chemical magic, as do I, but.......

Additionally, would someone guide me to an online reference, either here, or elsewhere if known, where I can access an online shop manual, or it's equivilent.

Thanks in advance to those who wish to help.

[Pete]

Try here for downloadable manual


...  version from Dag's website, http://valkyrienorway.com/. .

[Russell Rice]

I bought my manual from a dealership for $30 bucks. It was one that they used in the back so it had updates posted over the out dated pages, not a bad deal.
I would check with your dealer and see if they have a used one for sale.

[Mr. Nuts]

The mains almost never need cleaning or replacement.
This is a simplified method that doesn’t involve removing the carb rack. Its been a while since I did this but as I recall you’ll need:

GearWrench Microdriver set or equivalent. (This is a GREAT bike tool set for $24.99!) Similar available cheaper in cost and quality from HarborFreight.
http://www.sears.com/shc/s/p_10153_12605_00930035000P?vName=Tools&cName=Tool+Sets&sName=View+All&sbf=Brand&sbv=GearWrench&mv=tr

Small mirrors (free---steal from wife’s cosmetic drawer)

Intake O-Ring set for $12.49  http://redeye.ecrater.com/ (not required but a good idea)

Also a desmog kit from them if you haven’t already done that    http://redeye.ecrater.com/

18 allen head screws from your local hardware store to replace the screws on the bottom of your carbs since they are Japanese Phillips and easily goofed up.

An air filter replacement if you haven’t done that lately

Yarn or string for tying up the airbox tubes when you replace the airbox into the frame.

6 stock slowjets from your choice of vendor (couple bucks each)

Rags and bags to plug holes in block while you work on carbs.

Disconnect fuel line at petcock. Remove airbox and filter after loosening rubber sleeves at carbs. Remove polished intake tubes and 0-rings that run from carb bottoms to cylinder banks. Protect the holes in block by stuffing them with rags, plastic bags, tape, etc. You don’t want to drop anything in those holes! Use a ratcheting strap or equivalent to tie up one side of the carb bank as high as you can get it. Drain carbs by loosening drain screw on bottom of carbs. Remove 3 screws with angled driver or GearWrench tool and Phillips head  from bottom of each carb bowl being careful not to strip Japanese Phillips heads. Using stolen mirror, remove slotted slow jet and replace with NEW one. Thou shalt not cheapen out and try to clean except in extreme emergency. Replace bowl bottom with Phillips head screws in place of Phillips. Desmog now if desired. Repeat on other side. Remove rags in holes on block, replace o-rings with new ones since you are there (both sides) Tie airbox tubes towards center with yarn or string so you can sneak the box back into the frame. Cut the string and pull it out so the tubes can expand. Remove rags in holes on block, replace o-rings with new ones since you are there. Bolt carbs back up to intake runners at bottom. Fight and cuss to line up and refit airbox tubes to carbs. Replace air filter if needed. Replace tank. Hook up fuel line.

[Ricky-D]

From Capt7three:

"I need to replace my jets, it appears. Startup and idle is fine, acceleration after 3000 rpm is great. It stumbles from the getgo in first gear, and in any gear below that 3000 number."

Your problem is something other than jets!

You fail to provide information regarding throttle setting. Are you talking WOT ????

What about work that already has been performed on the carburetors? Surely must have been some because of what is happening!

How can you be so convinced that the problem is not ignition related?

***

[Pete]

Mr Nuts ---- excellent technique, excellent reply    ---- but

We have two areas we disagree on:

All that is left to remove the carbs is choke and throttle linkage and upper rear frame mounts and 1 coil. It is a whole lot easier to work on the carbs at the bench. And removal of the rear frame makes removing/reinstall the air box easier.

I prefer removal for ease of access. Just my opinion.

I have been successfully cleaning jets for many years, so that is the way I usually go.

Not being critical just noting areas of disagreement. Different folks different techniques.

Either way works when done carefully and correctly, not sure which would be fastest. I usually do not gauge speed as cleanliness is the most important issue to me.

[bish]

Not sure that your problem is jets or carb related, maybe. I just installed the Factory Pro 2.0 kit, but they do offer a kit for stock or near stock which includes everything you need except float needle and seat and you rarely need to replace those anyway. I did not remove carbs completly and it still took 6hrs start to finish. Make sure you check the emulsion tubes which hold the main jets. Also it is a good idea to change the O-rings on the intake runners. 

http://www.factorypro.com/index.htm

[beemerman750]

  trying to order slow jets from sudco they want to know what style slow jets anybody know name or number i told him slow jets 35 he sill insits on number and style

[John U.]

Based on the Sudco website:  http://www.sudco.com/keihinjets.html
and old slow jets I have laying around, the "style" is N424-21
The sudco order number for 35s is 019-005 , for 38s 019-006
If you click on the part number link on the above web page it will get you to a parts list that I got the Sudco part numbers from.
Good luck

[Mr. Nuts]

Mr Nuts ---- excellent technique, excellent reply    ---- but

We have two areas we disagree on:

I prefer removal for ease of access. Just my opinion.

I have been successfully cleaning jets for many years, so that is the way I usually go.

Thanks Pete! I appreciate it. I've only done it once and I'm certainly no expert. I like your way of thinking. If I ever have to do it again I'll sure try it that way. Thanks for the tip. I would never have even tried it without the help of good folks here like you.

[Mr. Nuts]

I need to replace my jets, it appears. Startup and idle is fine, acceleration after 3000 rpm is great. It stumbles from the getgo in first gear, and in any gear below that 3000 number.

After reading this better I also have doubts about the slow jets being your problem. I don't think your startup and idle would be "fine".  My experience was that my startup was difficult and my idle wasn't good. I could make it better with full choke left on, but it wasn't at all the smooth idle Valkyrie I was used to. Does full choking help with your symptoms? The rest sounds typical though. It stumbled a lot below 3000 and I had to keep the revs up to have it run nice.

[Pete]

It could be a vaccum leak causing 1 or 2 cylinders to run real lean below 3000.
But since the cleaning fluid helped, I would still suspect low speed jets.

By cleaning and replacing seal/orings etc and careful reassembly it should fix it if it is clogged jets or vaccum leak. Be sure and check all vaccum lines.

When doing carbs cleanliness is as important as careful reassembly.

[beemerman750]

  THANKS JOHNU FOR THE INFO ON THE SLOW JETS JOHN

[beemerman750]

  ANY BODY KNOW STYLE NUMBER OF STOCK MAIN JETS I GOT NUMBER OF SLOW JETS FROM JOHNU.

[John U.]

If you are running an OEM exhaust, you could just replace the main jet needles or shim the OEMs like a lot of guys do. Some of the "main jet kits" are just adjustable needles and don't actually include new jets. Maybe some who have experience with changing the main jets will weigh in.