Raising CV carb jet needles...

[hikermikem]

Where can I get the flat washers to raise the jet needles in my '82 GS650g?? There are no "notches" on these needles.

I bought washers at the hardware store and the ID is the right size, but the OD is a tad too big.

The issue I'm trying to remedy is the "flat spot" I have around the 3-5K range. Before 3K it pulls well, & after 5K or so it again pulls strong.

The carbs & bike are completely stock - I cleaned, rebuilt & sync'ed the carbs last year, also adjusted the valves but that flat spot still remains.

So... I've decided to try raising the needes .020" to begin with. Any thoughts out there???

Thanks,

Mike

[catbed]

i just did this today. i used two brass washers(was pretty close to half of the original plastic spacer) which i filed down as the OD was also too big. to do this, i sandwiched them on the shaft of a nail between the head and the chuck of a drill. then i clamped a file to my workbench and filed away. i filed all of the washers at once. runs much better now. now i guess i need to increase my main a little.

[rphillips]

Try Radio Shack, I don't know now, but back in the day, they had a perfect fit.

[chef1366]

Radio Shack has an assortment of small washers with the perfect size included. Bring your stock washer to match up.
Notice how much needle sticks out of the top of the needle over the plastic spacer. Remove the plastic spacer and stack the washers to the same spot. To raise the needle start removing the washers. One washer = 1/2 notch.
For a hesitation that is noticeable I would go one notch to start.

With a stock setup are you sure the airbox is sealed or some other issue?

[KiwiGS]

Help me to understand!?

Ok I am confused.
On My CVs the needle jet is the tube thingy with holes and a keyway in it that the main jet screws into, right?
If thats the needle jet where do you put the washers?
Mine has one brass washer between the (alleged) needle jet and the main jet. Is that where the extra washers go? and what effect will it have?

Cheers

[chef1366]

Ok I am confused.
On My CVs the needle jet is the tube thingy with holes and a keyway in it that the main jet screws into, right?
If thats the needle jet where do you put the washers?
Mine has one brass washer between the (alleged) needle jet and the main jet. Is that where the extra washers go? and what effect will it have?

Cheers

Jet needle. That's what rises out of the needle jet to allow fuel to flow from the main jet during the needle circuit. There are washers and spacers where the needle comes out of the slide.

[KiwiGS]

Jet needle. That's what rises out of the needle jet to allow fuel to flow from the main jet during the needle circuit. There are washers and spacers where the needle comes out of the slide.

Ahh! I get it now.
Thanks chef

[hikermikem]

With a stock setup are you sure the airbox is sealed or some other issue?

I redid all that last year, but I'll check again. Bike starts & idles very well, with no other issues except the hesitation between 3-5K.

I'll check out the Radio Shack stuff & try rasing up 1 notch. I believe that's around .040" (?) I remember reading here.

Thanks,

mike

[Nessism]

I did same as Catbed; stack a bunch of small washers on a screw, with a nut on the end tightened down, and stick the whole assembly in a drill/dremmel motor. Spin it up and using a file or sandpaper, reduce the outside diameter of the washers to the proper size. I did about a 20 at once and have had enough for two bikes to far (two washers per carb).

Good luck.

[robertbarr]

Radio Shack still carries the washer assortment, cat. 64-3022. Two bucks. I used a single shim on my '82 850 and it made a substantial difference in the bike's driveability in the most useful rpm range, just off idle to about 4 grand.

To add two, you might have to shorten the spring.

[Tony]

With a stock setup are you sure the airbox is sealed or some other issue?

I'm also wondering why you need to adjust the needles if you have a stock setup. Did you complete the rebuild or someone else? I'm just curious if you know for a fact that all carb components were placed to factory like settings.

I was just helping a buddy get his 83' 550 Honda nighthawk running. The PO gave him a newly "rebuilt" set of carbs with the originals already installed. PO bought the rebuilt ones because the old were causing gas to puke out the exhaust! Turned out to be a main jet loose in the bottom of the float bowl. We decided to put the "rebuilt" carbs in anyway because they were very clean. When I checked everything out before installation they were missing a needle jet, floats were out of adjustment, mixture screws not even close to factory settings, and many of the other jets were so loose they were ready to fall out. Also found that one of the needles must not have gotten cleaned because there was a good amount of buildup on it. That build up would cause symptoms similar to yours.

[hikermikem]

Thanks for the input guys. Yes, I did all the work on the carbs myself & put everything back stock: jet needles (1 of 4 was wrong), mains, pilots, float setting, intake o-rings, etc... all stock.

I've read here that raising the needles sometimes fixes the issue I've described - I'll let you all know after i do it in the next couple of weeks or so.

Hope your weekend is a good one!!

Mike

[doctorgonzo]

I just went the other direction on mine. Dynojet needles so adjustable, Went from the third notch to the second. Hope it helps my rich mixture. Seems to be running great with much more low end so far.

[doctorgonzo]

Hell yes!
My once black as midnight spark plugs are now sexy chocolate brown. Way more power in low rpm ranges. Moved needles one notch from 3 to 2, set the pilot screws to 2 turns, synced the carbs. Eureka!