another jetting question

[TheCafeKid]

OK- sorry for the interruption 8-[ As you were.

Tex your carbs dont have a "fuel" screw perse. They have an singular screw for adjustment purposes. Now, I just had this discussion with Steve the other day, as my 1100G has the same type of carbs, and I have never been really knowlegable on them, as i had never really messed with them, but apparently turning the adjustment screw will lean out or richen the overall mixture. the thing is, i cant remember which direction does what. He explained it as this. Know that turning the screw OUT adds more of something, either fuel or air, after that, it will be pretty easy to figure out which one. Some of the other guys might be able to tell us WHICH is added when turning the screw out...

[Texatl]

Cool!.

Again sorry for the hijack.

[horror1972]

another jetting question

Hi guys,

I'm confused :???:
I put 122 in it, as said the fuel and air screw about 1 turn out.
The bike runs, but only with choke fully open.
Tried fuel screw at 1 1/2 turn and air from 1/4 to 2 turns out, without any result.
is it still to lean, or what else can be wrong?

[KEITH KRAUSE]

Hi guys,

I'm confused :???:
I put 122 in it, as said the fuel and air screw about 1 turn out.
The bike runs, but only with choke fully open.
Tried fuel screw at 1 1/2 turn and air from 1/4 to 2 turns out, without any result.
is it still to lean, or what else can be wrong?

Opening the throttle bypasses the choke circuit, though there is some effect still.
I'm assuming by "the bike runs but only with choke" that you mean at idle or lower rpm's/smaller throttle openings? If you need choke to prevent stalling, then your pilot circuit is probably dirty/clogged. This also assumes the bike is otherwise tuned right which must be done first before you can accurately re-jet.
The valve clearances must be set between .03mm and .08mm, the ignition timing must be spot on, (if points) the points dwell set and the points cleaned, all electrical connections good and a solid blue spark, no intakes leaks, no exhaust leaks, CLEAN carbs with fresh inner o-rings and float levels set, clean pods/oiled properly if they take oil, etc. Then you can bench synch the carbs, re-jet, and then vacuum tool synch, then test. Basics.
Pods with a stock exhaust are a poor flow match in my opinion. Makes re-jetting difficult sometimes. You may have issues (hopefully minor) that can't be removed.
Some good advice given to you already. I'd probably try 3 to 4 full sizes up (15-20) on the mains for the pods. I believe your stock mains are 102.5 so I'd try 120's. Your stock jet needle e-clip position is #3, right in the middle of the stock 5 position jet needle. I think 2 positions richer (bottom position/5th from the top) is too rich. Either position 4 from the top or position "4 1/2" should work. If needed, position 4 1/2 is achieved by placing the e-clip in position 5 and placing an approx' .022" thick spacer directly on top the e-clip. Hard to say which position to try first, unless you go with the basic rule of always jet richer and work your way back. If K&N pods, I'd probably try position 4 1/2. If cheaper pods, I'd try position 4. Only solid 1/3 to 1/2 throttle tests will tell.
Remember, the thicker factory plastic jet needle spacer goes on top the e-clip and the thinner goes under the clip.
Also, the VM carbs MUST be vacuum synched everytime the jet needles/slides are disturbed. If you can't vacuum tool synch, at least bench synch very carefully. An unknown/poor synch will add to frustration and you may get uneven plug reads and less performance.
Try to make the stock 15 pilot jets work. Your pilot fuel screws underneath may have been moved in the past but try 1 1/4 to 1 1/2 turns out initially. Always set the side air screws using the highest rpm method.

[horror1972]

another jetting question

Tried everything.
first re-adjusted yhe ignition with a strobe and bench synch teh carbs.
out the needle on the 4th and 5th pos.
tried a 122 and a 128 main jet, tried with both setups the pilot on 1/2, 1 , and 1 1/2, still no effect:
bike runs fine at idle, but when i open the trottle a little bit, it stops accelerating and even almost dies.

when the engine is hot, and I put the choke at the middle, it runs a lot better, even respons to trottle.

what the he** is wrong???

[KEITH KRAUSE]

Tried everything.
first re-adjusted yhe ignition with a strobe and bench synch teh carbs.
out the needle on the 4th and 5th pos.
tried a 122 and a 128 main jet, tried with both setups the pilot on 1/2, 1 , and 1 1/2, still no effect:
bike runs fine at idle, but when i open the trottle a little bit, it stops accelerating and even almost dies.

when the engine is hot, and I put the choke at the middle, it runs a lot better, even respons to trottle.

what the he** is wrong???

Something isn't right or you've got something else wrong other than the carb jetting.
The jetting I gave you would not cause your problem.
I can only assume the bike is tuned correctly other than the jetting but I'm doubting that now.
If carb/jetting related. If it idles fine (pilot circuit) but won't rev past idle (using light throttle/still on pilot circuit), then some common problems are starved for fuel due to a clogged pilot circuit, float level is way off, large intake leaks not allowing enough vacuum to suck up pilot circuit mixture.
Starving for air can result in your problem too. Over oiling pods or oiling pods that aren't supposed to be oiled can cause this.
Your carbs are supposed to be VM 26 round slide carbs. Are they? Your problem also sounds like the classic damaged rubber diaphragm but those are only used in CV carbs. A torn diaphragm will allow idling all day but will accept no throttle. Can you show us a pic of your carbs if any doubt?

[horror1972]

another jetting question

Hi Keith,

I found , thanks to you, the inlet was leaking air.
I reassembled them with liquid gasket, so I will see the next morning.
I didn't mention I used a keyster refurbish kit; To be sure I put all the original mikuni stuff back with new o-rings, cleaned the carb again with brake-cleaner and air, and set the float height to 24 mm.








I'll let you know tomorrow,


Thanks,

Marcel

[KEITH KRAUSE]

OK. Hope it runs good.
Gotta mention though, new manifold o-rings should be used along with making sure the manifolds are in good condition too.
Using sealant between the manifold and head isn't the way to fix an intake leak.

[horror1972]

another jetting question

put new o-rings at the intake boots today, no result!

I removed the cover of the ignition while the bike was running, and saw that the breaker points were not sparking equallly, but now and then...

could this be the problem?

I ordered to be sure a new pair of contactbreakers, but forgot to order the condenser.
Can i get two of those at the elecronics-shop, I read they must be 0,25uF, or do I need original ones?

[KEITH KRAUSE]

Good spark is a basic tuning/maintenance issue. It needs to be done before jetting.
I can't answer if you can use some other condensor at an elect' shop. I'd suggest original parts. A Dyna S system would be better if you can do it.