Richer Needles / More fuel sooner?

[Anonymous]

When changing from an air box setup to pods, is it likely that the needle may have to let more fuel in a bit earlier.

Symptoms are persistant popping, sneezing, good strong idle,
problems start at about 1/8th throttle. Very low on power when trying to take off.

These problems can not be adjusted out using the air and fuel screws.

Could the needles be letting the fuel out too late for the new increased flow of air?

Lifting the needles is not enough to make the difference.

Anyone had any experiance here?

 

[moto_dan]

I would suggest the purchase of a Jet kit/performance kit(ie K&N). The kit comes with new needles(adjustable), jets(main and pilot), etc. with instructions and drill bit to drill slides and tuning troubleshooting guide.

 

[Anonymous]

ARE YOU SAYING THAT YOU ALREADY ADJUSTED YOUR NEEDLES????

 

[Anonymous]

The needles have been up and down, and swapped with shorter ones, although the taper started in the same place.
Bike always ran, but also always gave the usual popping and sneezing.

The popping and sneezing does seem to be pushed higher into the rev range, say from 2000 when lean to 7000 when really rich.
This is about 6km to the litre rich.

I've never had any experiance with jet kits, I soppose they would know roughly what to put in wouldn't they?

I've convinced myself that if the needle started to taper off a bit higher up, this would probably fix it. Does this sound like what you would get in a jet kit?

 

[Anonymous]

i have never been a believer in jet kitS but i know they give you a needle with an improved taper in most cases. i also have a motorcycle that has a constant slobbering --AS i cALL IT WHEN I AM JUST CRUSIN--IT GOES AWAY THE SECOND I GIVE IT THE THROTTLE.-- IN THE ABSENCE OF A LOAD THE SLOBBERING ALWAYS RETURNS AND I KNOW IT IS CAUSED BY THE WAY I HAVE THE NEEDLES SET--I HAVE STOCK NEEDLES AND ENJOY THE SOUND--BUT I DONT TUNE FOR SMOOTHNESS--THER ARE LOTS OF FOLKS WHO HAVE HAD THAT SAME PROBLEM AND HAVE CURED IT IM SORRY I DONT KNOW THE ANSWER- I JUST ASKED YOU THE QUESTION TO FIND OUT IF YOU INDEED HAD DONE SOME NEEDLE ADJUSTMENT EXPERIMENTING--SOME FOLKS FILE OR SANDPAPER THE NEEDLES FOR TUNING BUT I WOULD ONLY DO THAT IF I HAD AN EXTRA SET-GOOD LUCK AND I ALSO ASUME THAT YOU WANT A BIKE THAT RUNS SMOOTH ALL THE TIME--ONE AFTER THOUGHT IS HAVE YOU THOROUGHLY CHECKED FOR LEAKS IN THE EXHAUST AND INTAKE BOOTS

 

[Anonymous]

trotski- I just read your reply to my post from yesterday, and I was not necessarily after more power though I would not be opposed to the idea. I'm not sure If you're experiencing the exact problem I was, but my bike had all sorts of hesitation in the middle right around 1/8, to 1/5 throttle, it lasted for a few seconds and then when the fuel cought up, the bike took off like a rocket ship. Definately more power from the increased air flow. Short of a jet kit, I haven't had anyone tell me of another way to get more fuel in to match the air, and my budget doesn't exactly fit with a jet kit and the mechanics bill for rejetting, and to add icing to that cake, my mechanic won't take any more work untill august or september. Too long to wait for me, I went back to stock breathing and she runs perfect. Maybe at the end of the summer, I'll look into it further because there is more power to be had from the bike, and I can't say that I'm not a bit curious as to how much. all the info I got said larger mains and raised needles, both of which are in dynojet's kit. Have you tried their website?
Hope you find what you're looking for, I'd be interested to see what you come up with. Dominick.......

 

[Anonymous]

Just tried to get a jet kit and got told that they do not make them to suit my bike. They are only for CV type carbs they reckon.
Mine have the round slides.

Does this sound right?

 

[Anonymous]

Hey Trotski I am by no means an expert or anything but I was wondering if your chokes are adjusted properly. Also If you put the chokes on a little when the popping and surging is happening and it helps then you probably need more fuel/ bigger pilot jet. If it gets worse then less fuel/smaller pilot jet. The needle and needle jet dont come into play till over 1/4 throttle. hotrod

 

[Anonymous]

I'm not sure about the chokes being adjusted, they all go down ok
and are quite happily lined up along the bar that operates them.
Are they supposed to be adjusted?

Just tried pulling on choke at about 5000 rpm, where the problem is at the moment, didn't seem to help it but it did seem to kind of confuse it.

I am quite confident that the exhaust and intakes are sealing correctly and are not the cause of this trouble.

Do k&n really make jet kits? I tried their website and found nothing but filters. Is there anyone other than dynojet that makes
jet kits, preferably to suit my carbs. They were from a GS1000s, they are mechanical and have a 28mm venturi.

 

[Anonymous]

I have fitted an "air correcter" kit in the past to the VM28 carb you are talking about. The kit consists of a new main air jet which is embedded in the air filter end of the carb. This combined with a bigger main jet gives you the correct fuel/air ratio.
I got mine under the Ledar brand name from Straightline Racing here in the UK. They are GS tuning specialists. Their phone number is +44 (0)1553 811855. Ask for Nick.
There is no such thing as a Dynojet kit or similar for this type of carb, only for the CV type.
One further point worth mentioning is float height. When fitting this kit I was advised to change the float height to 19mm (from 24mm). This made a huge difference and my bike ran acceptably well from then on.
Hope this helps.

 

[Don Lobacz]

Are you sure that the carbs are 28mm? Did you measure it? In a previous post, I think you said that your pilots were #20s. These should be #15s, so you are 2 sizes too big. I tried 17.5s on my GS1000, and went back to the 15s. I have even seen pilot jets drilled out even further by industrious go-fasters (who would then have to sell off the bike since it wouldn't go around the block without fouling plugs). I would recommend rechecking all your components, try to get back close to stock and then work up slowly from there.

 

[Anonymous]

Hello there, thanks for the tips guys.

Yes the carbs have been measured, as difficult as it was, they are 28mm
across the narrow section of the venturi.

The pilot jets being too big would explain a few things.

I'm sure that an air correcter kit which gives the correct fuel/air ratio would help heaps too.

My carbs do already have a brass thing which looks like a jet in one of the holes in the back. Could someone have already done this?
They don't look as though they would come out too easily, do the new ones just push in behind the ones that are already there?

 

[Anonymous]

Yeah, sort of. You get a tap with the kit. The new main air jets are threaded with a screwdriver slot in. You tap a thread and screw them in.Obviously this works because they are smaller than the originals!
The original M.A.J.s are just a tight press fit.

keep going old son. :?