78 Skunk Carb base settings

[salty_monk]

Looking for some advice from those that have done this mod (Bruce, Tom et al) for some baseline settings.

I have the K&N pods, DJ kit arrived today & Nessim dropped the carb dip last night so I guess I'll be starting on them pretty soon.

DJ Kit states:

138 DJ main
Needle Groove 2
Washer above the E clip
Fuel Mixture 2.5 turns

Where did peops end up varying from this?

Is the fuel mixture screw the one underneath by the bowls? I think so.
The other one on top is an airscrew right? What setting should I run that at to start? (presumably then just set for "best idle").

This is the pipe going on:

It has a decent size baffle even though it looks mean. It's a Yoshi I believe so flow should be similar to your Jardine's or V&H's etc.

I'm at sea level.

Thanks for the help,

Dan

 

[tkent02]

The one high on the side of the carburetor is the idle air screw, adjust for highest idle RPM.
The one underneath, pilot fuel screw. This is the delicate screw with the tiny tip, be very easy and gentle when bottoming it out for a starting point. Mine needs about 1 or 1 1/4 turns out, they say 2 1/2? I guess do what they say. It's just a starting point anyway, you will tweak this. Keep all four together and adjust for nice running, throttle response and plug chops - all at just a tiny throttle opening, less than 1/8 turn. Ride around slow like under ten mph with next to no throttle, just putt to get it adjusted. Lean is good as long as it runs right on this one.
More throttle opening than this you are into the realm of needle position, and main jets, do what the jet kit makers say.

 

[Guest]

Here you go, Dan:

http://www.thegsresources.com/_forum/showthread.php?t=90568&highlight=GS1000+dynojet

 

[salty_monk]

Thanks Bruce, that guy was running cheap pods & a stock pipe though... more interested in your real world settings & Tom's (actually especially Toms as he's at Sea level like me).

Did you keep a record?

I didn't find what I was looking for with the search function either :lol:

Is it July yet???!!!

Cheers,

Dan

 

[Guest]

I'm sure Keith will chime in. But IIRC, he feels the jetting they suggest is a bit lean on the needle. I think he raises the needles one notch. 1 to 1 1/4 turns on the pilot screws, and the side air screws at highest idle, 1 1/2 to start. Synch the carbs and do your chop tests and adjust acordingly.

Mine is set at 3 1/2 notches from the top, pilot screws are at approx. 1 1/2, and side air screws are at 1 3/4. I used a colortune on my pilots, but didn't vary the setting more than 1/4 turn either way. But I am at altitude.

 

[Guest]

Here's Tom's settings:

http://www.thegsresources.com/_forum/showthread.php?t=108039&highlight=Keith+krause

 

[salty_monk]

I didn't find that one... thanks mate. I guess Tom's settings will definitely be a good starting point for me.

Gonna post them here for easy comparison:


TOM: I am currently 1 1/2 out on the pilot screw, 2 out on the air mixture screw (using the best rpm method), e-clip set at position #3 with the half spacer above the clip, bench sync okay, running sync dialed right in.

Be interesting to know if he's made any changes since. So with the Top position being number 1 I guess Tom is one full notch richer than you on the needles.

Did you both go with the 138's. I take it neither of you went to the 142's.

Dan

P.s. Bruce, Mucho brownie points on the poster, thanks mate!

 

[Guest]

Yes, 138's on the mains.

She liked it, eh? Cool! \\/ Brownie points are good coming from a woman!

 

[KEITH KRAUSE]

Thanks Bruce, that guy was running cheap pods & a stock pipe though... more interested in your real world settings & Tom's (actually especially Toms as he's at Sea level like me).

Did you keep a record?

I didn't find what I was looking for with the search function either :lol:

Is it July yet???!!!

Cheers,

Dan

For your conditions, I'd try the 138 main, jet needle e-clip in the 4th position from the top/no jetting spacer (be sure factory jet needle plastic spacers go back correctly...thicker spacer directly above the e-clip and thinner spacer under the clip), pilot fuel screws (underneath) initially set at 1 1/2 turns out from LIGHTLY seated, side air screws set initially at 1 3/4.
REMOVE the 2 floatbowl vent lines and leave the ports open.
Bench synch the carbs carefully. Be sure floats are set right in the middle of factory range, .94". I recommend Robert Barrs VM o-ring kit. I also recommend you replace the manifold o-rings at this time and also replace (if still stock) the Phillips screws holding the manifolds. Get some Allens and then you can torque the manifolds to about 6-8 ft/lb. Be sure to apply a coat of high temp bearing grease to the new o-rings.
Valves and ignition timing must be correct before vacuum tool synch. If you like, see if you can add a few degrees of advance timing AFTER you're sure it's running well. A few more degrees will make it even better as long as the jetting allows (no pinging/pre-ignition symptoms showing).
Be sure the K&N's are oiled properly, but not too much. It's too easy to over-oil if you follow their instructions as written. I use the spray and from about 4" away, I hit 2 pleats per pass. If you oil too much (pass too slow or hit 1 pleat per pass), the excess will not just "clear up" after some testing. It will run very rich/serious bog when opening the throttle past 1/4, depending on how much excess.
After the bench synch/initial screw settings are made, the bike should start. Warm it up fully and then fine tune the side air screws using the highest rpm method. On the centerstand preferred, check for correct throttle cable slack and then adjust base idle to 1,000/1,100 rpm's, no higher than 1,100. Starting at any carb, slowly turn the side air screw in either direction until you hear the rpm's max. This is generally in the 1 1/2 to 2 turns range. Re-set idle using the idle adjuster knob to the base idle. Repeat to all carbs.
Test the main at full throttle. Test the jet needles at 1/3 to 1/2. Test the pilot circuit at minimal throttle. Testing on an uphill or level is OK. The bike must be under load for the main and needle tests. General "cruising around" under 1/5 throttle is fine for testing the pilot circuit. Find a safe place to high speed test. Chop off and do what the plugs/performance say to.
Some pilot fuel screw adjustments are normal. Hopefully, the jet needles will be right the first time because the needles are by far the most work, requiring a new bench and vacuum synch each time the needles are disturbed.
Just be sure the bike is ready to re-jet so you don't confuse jetting issues with basic tuning issues.
Let us know if you need help.

 

[Tom MLC]

Thanks Bruce for the props.

Dan, I made no significant changes to those settings. I did re-check the pilot settings when we got the colortune. But like Bruce, I made no more than 1/4 turn either way. I'm betting you will have similar success.

Mate, be REALLY careful with those pilot screws. I busted a tip off in the carb body. And I know I just bottomed it out.

Yes, I used the 138 mains

 

[KEITH KRAUSE]

I'm not sure where Tom's jet needles are set, based on how he described them. I always count positions from the top-down. He sounds like he may be at 2 1/2(?), which is generally lean in my experience, quite lean actually. But bikes can differ. I've never seen a single 1000 run right on the DJ base settings for the jet needles. Even cheaper pods and a cheaper pipe want the needles richer than they recommend.

 

[salty_monk]

Hey Keith,

Thanks, I'm a glutton for punishment!!

Bike is having a bit of a re-build so I have all new O rings for intakes & Carbs etc
K&N's are pre-oiled from factory so should be ok I guess.

Haven't checked timing yet but bike did run before I stripped it. (Started easily on the choke, idled well & would run on all throttle opening but was obviously dirty from sitting since 1982! It stumbled a bit & chucked out some cr*p down the pipes for defo.)

Valves are all 0.05 or 0.06.

Will follow your instructions to the T & report back.

Just to be sure, fourth position from the top means the very top one is number one right & then count down to 4 of 6 notches?? There will be 3 empty notches above & 2 empty notches below in that case.

Thanks again.

Dan

 

[Tom MLC]

This is the pipe going on:

Funny how stuff gets around. I took that picture. On a blanket in my driveway. Before I sold the pipes to PJ. Obviously you got the pic from him. How funny.

 

[KEITH KRAUSE]

Dan, yes, there will be 3 open notches above the clip and 2 below if the e-clip is in position 4.
I'm only speaking from experience but I think some don't realize they may be lean. That doesn't mean they ARE lean but they should check. A lean condition can make a lot of power and fool you into thinking the bike is running great. In some cases of running moderately lean, you can get away with it, especially if you don't run it on longer rides. Some just don't notice surging or other lean symptoms like others can.
For these reasons, I think many just don't test as they should. The very first time I tried a DJ kit was on 3 '79 1000's at the same time. Only difference between the bikes was 1 had a Kerker pipe. My 2 friends ended up letting me do most of the work, but they tested and helped a lot. We tried the base settings because we didn't know any better way to start. We tested in a great location and followed basic testing and tuning exactly. All 3 bikes hesitated and surged noticably on the jet needles. Long story short, I've never jetted a 1000 any "leaner" than position 3 1/2.
I know bikes can differ, even if under similar conditions but I just have to mention what I've found.

 

[Guest]

I'm at 3 1/2 on my needles at 5200 ft. I'm still just a tad rich, but I like it like that. I can go to a lower altitude and not worry about running too lean. Keith, your recommendations were spot-on for my bike/altitude. You obviously saved me alot of time and frustration. I read about all these horror stories on people's re-jetting issues and all I can say is "dang, mine was easy!" :-D
I also think people don't realize how important it is to have all the other issues worked out first (timing, valve clearances, etc.).

 

[Tom MLC]

I'm not sure where Tom's jet needles are set, based on how he described them. I always count positions from the top-down. He sounds like he may be at 2 1/2(?), which is generally lean in my experience, quite lean actually. But bikes can differ. I've never seen a single 1000 run right on the DJ base settings for the jet needles. Even cheaper pods and a cheaper pipe want the needles richer than they recommend.

Well Dan, and by proxy Keith, I remember taking Keith's advice on the needle settings. I had my carbs running a little richer than they are now. I recall I didn't like it too much. But I don't remember why I didn't like it. I'm sure it was just my novice level experience, which is certainly flawed. But after much experimenting I ended up wher I'm at.

After reading the Guru's advice again, I'm going to re-think my settings.

One thing that comes to mind is the mediocre performance I experienced on the DynoDrags in Reno last year. I expected better results after the mods. Our sister skunks should have been closer. Heck, I have a 40 pound weight advantage on Bruce, and everyone knows I'm a better drag racer that he is. :-\". Yet he beat me easily in four races.

So I'll be anxious to hear about your results. And when I get around to it, I'll post mine.

 

[KEITH KRAUSE]

Tom, I'm only questioning the jet needle position you chose, not any other part of the jetting.
And like I meant to say, it's just my gut feeling. If I had your bike here and after checking a few things, I'm thinking a couple of solid 1/3 or 1/2 throttle runs would show plugs in the grayish/white area? Maybe not. It would be easy to find out though.
I'm not sure why your bike is (according to you) slower at drag racing than Bruce's. If you're questioning the jetting, you're right on the main jet during the whole run and the 138 main works well for basic pipe/pod and also 1085 kit mods.
What are your exact mods?? Cam timing matters A LOT and is the single most common reason for identical/nearly identical bikes to have different performance.