New (to Me) 2000 Kawasaki W650

[zwish]

Originally Posted by Speedo66

I shimmed the needles. Did it the same time I turned the idle screws out. Runs great now, but can't tell which actually did it, or if it was the combination of the two.

The "how to" photos and explanation used to be on the "Capt. Jake" site, but wasn't last time I looked several months ago.

Yeah, I remember you saying a while back that you shimmed your needles. I've been hoping that would pop back up on Capt's site. No luck yet. I've heard mixed reviews about the needle shim. Some people said it didn't cure anything and hurt mileage. Other's like you said it might contribute to a better running bike. I'll have to take a look at that. It seems like a rejet might be my best bet. Wonder what that would do to the MPG.

[ORexpat]

Shimming the needles affects the main jets, which come into play, so I've heard, around 3000 rpm or thereabouts.

I did the same thing, but all it did for me was use more gas without much other effect. So I took the shims out. (Pretty easy to do--much easier than the pilot jets. And easy to reverse if it doesn't work out).

YMMV . . . . .

[Blakebird]

The previous owner of the one I recently bought had put in Thruxton needles, which apparently have a richer taper. He'd also exposed the fuel/air screw and backed it out 1/2 turn.

On a cold morning it needs choke to start, but can be ridden away in a minute. It carburets crisply.

Originally Posted by zwish

Hey gang, It's been a while since I've posted. The W650 and I are still getting along famously. The one issue that rears its head from time to time, especially in these frosty winters is the lean nature of the bike. It seems that once the bike warms up it's fine, but still a bit on the lean side. The long warmup period is what gets me. I've read through this thread multiple times over through the past 8 months or so, but I'm curious. Those of you who have modified the fuel mixture, whether it was air mixture screws, rejetting, going with pod filters, etc, What has worked well, would you do it again, what were the effects?

The only thing that I've done is turn the air mixture screws out 3.5 turns, and block off the Clean Air System with a marble. The marble has stopped the backfiring when you clutch-in, but the bike still feels like it's not riding as smoothly as it could for the first 15 min or so. I did not have this problem with an 860cc carbureted Bonneville, so I don't think it's an issue of a larger displacement engine taking a while to heat up. The W650 however has been perfect as far as reliability is concerned. It never misses a beat. Anyways, just curious what you all were doing to your bikes. Thanks.

[Pigford]

Here you go.........

Originally Posted by Pigford

As for carb changes..... My set up is really sweet now...... the standard set-up is rather lean I've removed the air emission crap

I fitted a Sygma 6 kit from eBay. Running with STANDARD pipes & airbox & filter.
Main jets up to 122.5 and pilots up just one size (both carbs the same).
I did have a couple of shims fitted under the needles, but took them out again as the 1/4 - 1/2 throttle was a bit rich.
No other mods apart from setting pilot screw 3 turns out (only a rough guide as bike to bike & altitude will effect this).

Raising the needles make the mix richer - effecting 1/4 - 3/4 throttle range (approx) - it isn't necessarily related to rpm !

The pilot jets defo need to be upped 1 x size to help the poor part throttle running/spit back & slow warm-up.

To ensure the air:fuel ratio is not overly lean at over 1/2 throttle opening, try upping the main jet a bit.... leave the needles until you've done this first.

[pjensen641]

The general consensus on the Yahoo W650 group is that the main jet is already too RICH. I believe stock is about 118 and the ideal for stock air box and exhaust was found to be 112 by several who have dyno run and checked AFR with a sniffer. The overly rich main makes up for the non-ideal needles.

The needles are not tapered enough, this is an emissions thing. It allows really lean running in the operation range where the emissions are evaluated (low to mid throttle), then the overly RICH main jets help protect the engine at high load/rpm. Ideally, you should buy a jet kit with needles that have a more aggressive taper so that a 112 main can be ran, this will give a more consistent AFR throughout the operating range. The Factory Pro jet kits have the necessary needles.

The idle jets seemed like there was no consensus. Either run the stock and back the idle screws out to 3.5-4 turns (or there abouts) or go one size bigger and turn the screws in. I read opinions that going to the 38 idle jets caused increased consumption, and it was better to keep the stock 35's with backed out screws. If you don't care about increased consumption, go with the 38's to get a quick warm up.

This is all information I am regurgitating and paraphrasing from the Yahoo W650 group. I can't link the exact posts, but if you join and do a message search for "Jet Kit" or "Factory Pro" I think you will find the information.

[Pigford]

Pjensen641 - thats interesting - and I agree that either have "waisted" needles to increase fuel at a set needle/throttle opening to make a bit richer..... or a larger main jet.

As you rightly say, a DYNO run is the only 100% way to evaluate the A/F ratio to ensure you're not running lean at WOT (Wide Open Throttle), which could spell disaster if the main jets are too small !!!

One point with the pilot jet and the pilot screw.... it's generally accepted that once the screw is open over about 3 or 4 turns, the screw has zero effect as the passageway is full open..... so if you start winding it further the next size pilot jet is needed.

NOTE: The PILOT SCREW is in fact a method of controlling FUEL flow - not AIR (as in AIR SCREW)..... this is usually distinguished by the fact that the scew is the ENIGINE side of the carb - not the AIR BOX (intake) side So if the screw needs to be wound out, it's to make the part throttle circuit RICHER.

Due to the sh*te weather here (UK) I haven't had chance to go for a decent run to do a plug-chop, so can't comment to specifically yet.

[Barnone]

Originally Posted by Blakebird

The previous owner of the one I recently bought had put in Thruxton needles, which apparently have a richer taper. He'd also exposed the fuel/air screw and backed it out 1/2 turn.

On a cold morning it needs choke to start, but can be ridden away in a minute. It carburets crisply.

Triumph Thruxton (NBZT)
length
2.152
Diameters
tip+ 0.0 = 0.066
tip+ 0.2 = 0.070
tip+ 0.4 = 0.074
tip+ 0.6 = 0.079
tip+ 0.8 = 0.084
tip+ 1.0 = 0.090
Taper begins
Tip+ 1.330
Non taper Diameter
0.097

Anybody got the specs on the stock W needles?

[acap650]

Originally Posted by Barnone

Triumph Thruxton (NBZT)
length
2.152
Diameters
tip+ 0.0 = 0.066
tip+ 0.2 = 0.070
tip+ 0.4 = 0.074
tip+ 0.6 = 0.079
tip+ 0.8 = 0.084
tip+ 1.0 = 0.090
Taper begins
Tip+ 1.330
Non taper Diameter
0.097

Anybody got the specs on the stock W needles?

W650 needles are different left and right because airbox design is not symmetrical. Different part numbers for each side here:
http://www.powersedge.com/pages/OemP...fC19C1946E1612

[Barnone]

Funny that the Dynojet kit has both needles the same.
STAGE ONE INSTRUCTIONS
1. Remove the vacuum slide from the carbs. Remove the stock needles & spacers, noting the order of assembly.
2. Install the Dynojet needles on groove # 2, using all stock spacers (Fig. A). Install the adjusting washers above the
e-clip (2 per needle). Install the Dynojet slide springs (DSP005) in place of the stock slide springs.
3. Remove the main jet and replace with the Dynojet main jets provided. Use the DJ108 main jets with stock exhaust.
Use the DJ112 main jets with aftermarket headers or slip-ons with free flowing baffles. Be sure that the jets you are
changing are the main jets.
4. Locate the fuel mixture screw (Fig. B). If you see a screw head, proceed to adjusting procedure. With the plug drill
(DD #5/32) provided, carefully drill thru the plugs. NOTE: The mixture screw is directly underneath this plug, be ready
to pull back on the drill the instant you break thru. Use screw provided to secure and remove the plug. Carefully turn
mixture screw clockwise until seated, then back out 3 turns.
http://www.dynojet.com/pdf/2176.pdf

http://www.ebay.com/itm/00-02-Kawasa...-/310292839382

[zwish]

So has anyone installed that Dyno kit? Looks like it could be a good solution. Thanks!

[rulle_retard]

I have the dynojet stage 1 needles on my bike and a 2-1 exhaust with original air box. When I installed the kit with the clip on groove #2 the bike was almost impossible to drive, it was running to lean. Like when the tank is almost empty, but all the time! I then moved the clip down to groove #3 to make it richer, now its running like a champ. I change them right before the winter arrived so I havent had the chance to test it "full out" but it feels more "smoother" and like it has more "power". I doesnt remember how many turns out my fuel mixture screw are thou... think it is about 3,5-3,75

[zwish]

What are you talking about when your saying "clip to groove 2, groove 3, etc." Is this a part of the dyno kit? Thanks.

[rulle_retard]

Oh, sorry! On the dynojet needles you can either lower the needles (by placing a clip on a higher groove) or raise the needles (by placing a clip on a lower groove). Unlike the original needles that only has one "stop" on one side of the needle. Here you can see the grooves (on the left side of the needle) and the clip on the #2 groove.
http://faq.ninja250.org/images/1/16/Jetneedle-horiz.jpg

[zwish]

Ah perfect! Thanks for the clear description. Would you have installed the kit if you weren't running aftermarket pipes?

[rulle_retard]

Hmm I dont really know, doesn't know if it will run better with dynojet needles and stock pipes. But I guess it will! Its a very simple procedure to install the needles, you don't even have to take the carbs of the bike so it will take like 30 min to do it!