Jet Needle Question URGENT

[TheCafeKid]

You said your fuel inlet screw (the one in the bottom of the float bowls) was 1.5 turns from seated? Thats way too rich, even with a new filter and header. STOCK should be about .5 to .75 turns out... thats probably your issue...

 

[Rick65Cat]

You said your fuel inlet screw (the one in the bottom of the float bowls) was 1.5 turns from seated? Thats way too rich, even with a new filter and header. STOCK should be about .5 to .75 turns out... thats probably your issue...

Yep, when I reassembled the carbs that screw is now at 3/4 turn from seated to get the bike running. Plug chops will be done.

 

[Rick65Cat]

Holy yumpin' yimminy.
When they manufactured these bikes back in the day, the friggen assembly line sure must have slowed down when it got to the poor sucker who had to install carbs.
Everything is pretty much installed and now I'm just going to take my gas can and get a couple of gallons of gas. Hopefully theres no leaks when I open the petcock to prime.
Stick in the battery and we'll see....

 

[tkent02]

I'm going to guess here, if you have a stock bike except for a Mac pipe, which flows no better than stock, and if you are trying to tune for Alberta's elevation, isn't it 4,800 ft. or so?
I would think 102.5 main jet would be too big for a GS1000, and cause it to run quite rich.

Did you do a complete series of plug chops to determine you needed bigger jets, and to determine which jets needed to be bigger?
Or did you dyno runs to analyse the mixture?

Or was the 102.5 a suggestion from someone else?

 

[Rick65Cat]

Its alive!!!!!!!!!

Its alive!!!!!!!!!

I'm going to guess here, if you have a stock bike except for a Mac pipe, which flows no better than stock, and if you are trying to tune for Alberta's elevation, isn't it 4,800 ft. or so?
I would think 102.5 main jet would be too big for a GS1000, and cause it to run quite rich.

Did you do a complete series of plug chops to determine you needed bigger jets, and to determine which jets needed to be bigger?
Or did you dyno runs to analyse the mixture?

Or was the 102.5 a suggestion from someone else?

As far as I know the bike is stock, and even though I live here I'll be darned if I know the elevation.

Plug chops have not been done yet. I have to renew my plate for 2010. Registration places are closed today for the holiday but I'll get it tomorrow. Nice thing is my insurance is good til this sept

I had my jetting done here in Edmonton at a shop that is supposed to be an expert at the old Jap multis. They were the ones that put in the 102.5's.
What I've found out (after disassembling the carbs) was all they did was increase the mains, and most likely richen up the pilot screws (1 1/2 turns from seated). My needles were never touched (clip was still in the 3rd slot). So to say I'm dissapointed in the work would be an understatement. Especially when the owner is the guy who told me what was done when I asked specificly what jets were done and by how much.

BUT!!!
On a super plus note......IT FIRED RIGHT UP!!!!!!!!

Put the tank on, hooked up the hoses, dumped in 10 liters of 91 octane, then turned the fuel cock to prime...and prayed. Waited a good minute and no leaks!
I cranked the engine with no choke to get the oil circulated til the oil light went out.
Half choke, turn the key, hit the starter....about 5 revolutions then VROOM.
As it warmed the idle crept up til it was at 2500 rpm with no choke. I turned the idle down and it just friggen PURRED at 1000 rpm with no burbles.
SUHHHHWEEEEET!!!!!!!!!
I'm so freakin pumped you can't believe. And I was so worried I was gonna bugger something up re-assembling the carbs.

 

[Guest]

Now go ride the dang thing!!

Happy for ya!

 

[Rick65Cat]

Ok, heres how today broke down. I was going to drive my bike around to warm it up then stop on the side of the hiway leading north out of Edm and change the plugs out for new ones. Then drive up the shoulder at 30 mph at low throttle and do a plug chop for the pilot screws.
Lo and behold, I get my stuff together and go outside to start the bike...the battery is too weak to start it
So I boost it off my car....Now I'm thinking I DON'T want to shut it off far from home in case it won't restart. So I drive around never getting above quarter throttle for about 20 min...come down the long street back to my driveway at about 3,000 RPM and just before I have to slow for the turn into my complex, I hit the kill switch and pull in the clutch.

This is one plug. Now...these plugs were brand new for when I started the bike after redoing the carbs. I had the bike running maybe a total of 7 minutes yesterday on choke and at idle.
What you see is from that 7 minutes from yesterday and the 20 minutes today.
Side screws are 1 1/2 turns out and pilot screws are 3/4 turn out
I have my ideas, but I want your opinion.

Oh, BTW...turning the sidescrews in or out yesterday made NO difference to the idle speed (no choke)

 

[TheCafeKid]

Looks a hair lean to me.. but pics are hard to tell.. I think I see some TAN down in there..which is good.. But if its running well, and the plugs arent jet white and pitted, ride it around for a bit, see how it feels.. The plug chops are good, but if you let yourself, you can simply go INSANE trying to get the perfect mix...the absolute best tell is how the bike responds, period. *I* dont think that plug looks unsafely lean. I probably wouldnt mess with it MUCH more, if I wasnt able to get it just a tad darker than that..

 

[Rick65Cat]

K..thats one reply, anyone else?


I'm tending to agree about the lean "look"...now.
And yes, it was sunny when I took those pics. The soot I think was from yesterday.
After examining all the plugs, I turned The pilots in another 1/8 turn. And I think I fooled myself with the soot on the plug.
Driving it after turning the screws in, it now pops and backfires on deceleration. And, when I pulled into my driveway I pulled in the clutch to stop and it stalled.
During the extended ride around the city, it seemed to run well. But one long stretch of continuous throttle I'm positive one cyl. cut out so that it ran on 3. Dunno whats up with that.
What I think i'm going to do is warm it up tomorrow then change out the plugs for the new ones, do my little run down the shoulder and chop it. Then check the plugs there on the side of the road.

 

[chuck hahn]

IN leans it out..may have wanted to go out that 1/8 turn...

 

[TheCafeKid]

Say, not to bring up a sore subject, but were it me, I'd lose the inline filter you had going on there (i just looked over your carb pics in the thread again).. Gravity fed systems dont like turning restricted corners... There is a great filter in your petcock too..so unless you have some serious flaking rust going on in your tank, the inline filter is just an added restriction to the fuel system..

 

[TheCafeKid]

IN leans it out..may have wanted to go out that 1/8 turn...

On the AIR screw (the one on the side of the carb) IN will richen the pilot circuit.. OUT will lean it out (lets more air in) the opposite of this is true for the FUEL screw on the bottom of your carbs. BUT you SHOULDNT have to mess with the fuel screw.. Make the air screws do the work...

 

[Rick65Cat]

Yup, going back in that 1/8th turn this morning before I start it. Also going to pull the plugs after yesterdays riding and see what they look like now. I may as well throw in the 4 new ones too before I fire it up.

I was thinking about that filter not realizing theres one on the petcock. If thats the case, I'll lose it. Its a pain in the a** trying to get the hose (that filters attached to) onto the petcock. I have to raise the bloody tank again anyway since I forgot to connect the fuel gauge wires.

 

[Rick65Cat]

Heres the 4 plugs from yesterday. As you see them is how they would be in the bike if you were sitting on it looking down. Right plug from right side cyl and etc.
Only on the extreme right cyl. is the center insulator visible. The other 3 are sooty.
On the 2 center plugs the *curved* electrode isn't as white. To me that means the 2 middle pilots aren't as lean?

I guess I shouldn't have moved the needles the 1 notch richer either.

Sorry to keep on with one subject over and over.

 

[srsupertrap]

Not an absolute but when running a 4/1 your plugs will not necessarily be 100% identical. No big deal. Yes it was a mistake to move the needle clip one full position. Restore to the way it was yesterday, those plug chops from yesterday very pretty damn close considering they had some color after 20 minutes of riding. How many turns out are you currently on 1) pilot fuel screw 2) pilot air screw. You want to find that pilot fuel screw sweet spot were the air screw does affect how it idles.

We should stickey this one just because.

Pilot Mixture air screw rule of thumb: "If the air screw is located between the carburetor slide and the engine (BS Carbs), turning the screw out richens the mixture. If the screw is between the carburetor slide (VM Carbs) and the air cleaner turning it in richens it." Joe Minton

 

[Rick65Cat]

On the AIR screw (the one on the side of the carb) IN will richen the pilot circuit.. OUT will lean it out (lets more air in) the opposite of this is true for the FUEL screw on the bottom of your carbs. BUT you SHOULDNT have to mess with the fuel screw.. Make the air screws do the work...

Taken from Paul Musser's VM carb rebuild sheet.....(some cutting here also to get across what I want to question)

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Pilot air screws​

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[FONT=Times New Roman,Times New Roman][FONT=Times New Roman,Times New Roman]?also known as [/FONT][/FONT]side air screws, or pilot screws, [FONT=Times New Roman,Times New Roman][FONT=Times New Roman,Times New Roman]control air flow into the idle circuit. [/FONT][/FONT]
[FONT=Times New Roman,Times New Roman][FONT=Times New Roman,Times New Roman][/FONT][/FONT]
[FONT=Times New Roman,Times New Roman][FONT=Times New Roman,Times New Roman]2. See if there is a nick next to the screw head lined up with one end of the screw slot. That is put there by the factory to help reposition the screw if it?s removed. Turn each one in until it bottoms, counting the turn(s). Write down the number of turns then unscrew and remove.[/FONT][/FONT]
[FONT=Times New Roman,Times New Roman][FONT=Times New Roman,Times New Roman]***[/FONT][/FONT]

***Turn each side pilot air screw slowly (both ways) up to one full turn until you hear the engine speed max out. When the engine speed stops rising, stop turning. You may want to go back about [FONT=Times New Roman,Times New Roman][FONT=Times New Roman,Times New Roman]⅛ [/FONT]turn to allow for listening error. These screws usually end up about 1? to 2 turns out. ***[/FONT]
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[FONT=Times New Roman,Times New Roman][FONT=Times New Roman,Times New Roman]Ok...I have those little "nicks" next to the screw herads. My question is...which end of the screw slot do you use????[/FONT][/FONT]
[FONT=Times New Roman,Times New Roman][FONT=Times New Roman,Times New Roman]Right now I'm 1 1/4 turns out. I could twist the screw head and either end of the slot would line up with the "nick" before I get to 2 turns out.[/FONT][/FONT]
[FONT=Times New Roman,Times New Roman][FONT=Times New Roman,Times New Roman] ​

[/FONT][/FONT]

 

[TheCafeKid]

Taken from Paul Musser's VM carb rebuild sheet.....(some cutting here also to get across what I want to question)

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Pilot air screws​

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[FONT=Times New Roman,Times New Roman][FONT=Times New Roman,Times New Roman]–also known as [/FONT][/FONT]side air screws, or pilot screws, [FONT=Times New Roman,Times New Roman][FONT=Times New Roman,Times New Roman]control air flow into the idle circuit. [/FONT][/FONT]
[FONT=Times New Roman,Times New Roman][FONT=Times New Roman,Times New Roman][/FONT][/FONT]
[FONT=Times New Roman,Times New Roman][FONT=Times New Roman,Times New Roman]2. See if there is a nick next to the screw head lined up with one end of the screw slot. That is put there by the factory to help reposition the screw if it’s removed. Turn each one in until it bottoms, counting the turn(s). Write down the number of turns then unscrew and remove.[/FONT][/FONT]
[FONT=Times New Roman,Times New Roman][FONT=Times New Roman,Times New Roman]***[/FONT][/FONT]

***Turn each side pilot air screw slowly (both ways) up to one full turn until you hear the engine speed max out. When the engine speed stops rising, stop turning. You may want to go back about [FONT=Times New Roman,Times New Roman][FONT=Times New Roman,Times New Roman]⅛ [/FONT]turn to allow for listening error. These screws usually end up about 1? to 2 turns out. ***[/FONT]
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[FONT=Times New Roman,Times New Roman][FONT=Times New Roman,Times New Roman]Ok...I have those little "nicks" next to the screw herads. My question is...which end of the screw slot do you use????[/FONT][/FONT]
[FONT=Times New Roman,Times New Roman][FONT=Times New Roman,Times New Roman]Right now I'm 1 1/4 turns out. I could twist the screw head and either end of the slot would line up with the "nick" before I get to 2 turns out.[/FONT][/FONT]
[FONT=Times New Roman,Times New Roman][FONT=Times New Roman,Times New Roman] ​

[/FONT][/FONT]

When you set the air screw to lightly seated..which side of the slot was facing the nick? Thats your starting point. When that side of the slot comes back around to the nick, thats one full turn. The opposite side of the slot at the nick would be a half turn.. it helps to count as the slot lines up. starting at zero...one half, one, one half, two, etc..its also possible that the 'sweet spot' ISNT at the nick..you could find that it idles best (when you get to setting the highest idle with the screws, just get it running now) at 1 3/4 turns out, or 2 1/4 turns out..Its not an exacting science.. *listen* to the bike, it will tell you..

 

[Rick65Cat]

I've given up for the night....sadly by the time I get off work during the week its to late to work on it since I don't have a garage. Its gonna have to wait til next weekend.
This afternoon I started the bike with the needles back on the 3rd notch as per stock, the side screws out 1 3/4 turns and the pilot screws 3/4 turn out.
Bike ran but not the best. I thought it was just still not up to temp. When I got out on the road it was obvious it was too lean. I came back and turned the side screws back into 1 1/4 turns out and the bike ran wayyy better.....THEN....

A half mile from home it started stuttering like it was starving. By the time I managed to get home it was running on only the 2 center cylinders.
Pulling the outter plugs shows no real deposits on them and no smell of gas. The bowls have fuel, its just not getting through.
Oh, and when I was struggling to get it home..I'd reef on the throttle and then it would run on all 4. I'm thinking theres a blockage somehow somewhere.

Say....is there a spec length/number of coils on the spring for the pilot screw? Its a crazy thought but, if theres too many coils on this carb kit pilot spring it wouldn't allow you to screw the pilot all the way in to its full depth right? That would end up giving you a false reading when you attempt to turn the screw out X number of turns from seated.

 

[srsupertrap]

I have never used but others have stated those K&L / Aftermarket carb kits are a crap shoot. If you have the original pilot screw springs I would suggest installing them instead. It's a problem if you cannot lightly seat the screws because the new springs are too long :evil:

 

[Steve]

When trying to use the "nick" to line up the mixture screws, remember that the factory put that nick there when the carb was brand new and about as perfect as it would ever be.

There is a very good chance that the "nick" won't be the sweet spot any more.

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