Fluctuation problem with throttle...

[IcyChaos]

I have a 2000 Bandit 1200S with a Stage 2 Jet, Yoshi exhaust and K&N Pod Filters.

After I cleaned and re-oiled my K&N Filters, Im having a wierd fluctuating throttle response.
I went on a ride yesterday, in sorta cold weather 50's, and I had problems in 1's and 2nd gear. If I keep the throttle in 1 position, say cruising at 60MPH, the trottle is acting like Im holding open, then close, open then close, all when I keep it in 1 position.
Towards the end of the day, I wasn't having problems in 1st and 2nd, but on the interstate it was acting up again in 3rd and 4th.  Regardless of what RPM's Im in.

When I reoiled the K&N I let it sit overnight until I put it on the bike, but still I feel like there was a lot of Oil dripping off the filter. Im wondering if this could've caused this problem, or maybe there's something wrong with the jetting? My gas milage is pretty bad,  at around 27Miles per galon. But I do ride hard.

[Red01]

Over-oiling could be part of the problem, but if you're getting 27 mpg, I'd have to say you're running way rich.

I have a Holeshot Stage II jet kit on my 2G with a Holeshot can and I regularly get 39 mpg, and if I'm really hard on the throttle for a whole tank, I might be able to get it to drop to 36-37. The 1G's will commonly do a little worse in fuel economy than the 2G, but not 10 mpg different.

[IcyChaos]

Over-oiling could be part of the problem, but if you're getting 27 mpg, I'd have to say you're running way rich.

I have a Holeshot Stage II jet kit on my 2G with a Holeshot can and I regularly get 39 mpg, and if I'm really hard on the throttle for a whole tank, I might be able to get it to drop to 36-37. The 1G's will commonly do a little worse in fuel economy than the 2G, but not 10 mpg different.

Is there an easy solution to fixing the mixture?  Or do I need to get an Adjustment for the Jet 2 kit.

I can get it adjusted for around $160  but I hardly have that to spend right now.

As with the overoiling, It seems like its not as bad right now, and I wonder if riding more and more will just get that oil out of the system.

[Red01]

If your mpg doesn't improve with time - or if it has been this bad since the kit was installed, you do need to go in and lean out your settings. You might try just putting the clip in the next higher (closer to the top) groove.

Since it's not over-oiled to the point of not running, eventually it will suck the excess oil from the filters and burn it, but it could also foul plugs while it's doing that.

[IcyChaos]

If your mpg doesn't improve with time - or if it has been this bad since the kit was installed, you do need to go in and lean out your settings. You might try just putting the clip in the next higher (closer to the top) groove.

Since it's not over-oiled to the point of not running, eventually it will suck the excess oil from the filters and burn it, but it could also foul plugs while it's doing that.

hmmm, maybe just getting new plugs will eliminate this problem.

My gas milage was around 30-31 before the K&N re-oiling.  I think with time this problem will fix itself,  seemed to run alot better today.

[kedeg_97B12]

Did you install this Stage 2? How long ago?

Do you know what clip your needles are at?

How long have you had this bike?

When was the las time you changed/checked the plugs?

You needn't pay someone to do it. It is as easy as it gets. Especially on the 1st gen.

[IcyChaos]

Did you install this Stage 2? How long ago?

Unfortunately no, I bought it used with the jet2,k&n and yoshi pipe.

Do you know what clip your needles are at?

No idea, and honestly don't know whatcha mean by that...

How long have you had this bike?

Me, maybe 4 months. Bought it with only 8500 miles on it

When was the las time you changed/checked the plugs?

I haven't but it might be time soon

You needn't pay someone to do it. It is as easy as it gets. Especially on the 1st gen.

How do I know what Gen my bike is,  Its a 1200S   2000 model

[Red01]

A 2000 is the last year of the 1st Generation of 1200's.

The needle is inside the carb slide. Here's a pick of an adjustable needle:



(This one's from a 2G B12 Holeshot stage II kit, but yours should look similar.)

[IcyChaos]

A 2000 is the last year of the 1st Generation of 1200's.

The needle is inside the carb slide. Here's a pick of an adjustable needle:



(This one's from a 2G B12 Holeshot stage II kit, but yours should look similar.)

Hmm how easy is this changing the needles??
What does it do, and how can you tell what their set at?

Also when Jet2 is done, they test it using a Dyno, is this necessary when messing wit the needles?

[smooth operator]

1st (my2cents) take a paper towel or clean rag and pad off any extra oil on the filter(s). they only need a light coat of oil on them, or clean them up and start over. 2nd,befor messing with the carbs put in a new set of plugs take it for a good ride and take a plug reading.If the bike is running rich your plugs should be on the dark side.You want a light brown,maybe a bit toward the lean side. If you need to drop your needles down I pull mine out the right side,make sure you procect any paint on your frame that you don't want scratched.You don't have to unseat the diaframs,I don't disturb them if you don't have to.Do 1 at a time and don't loose the little o-ring. When you take the cap off sometimes it will stick to the cap. If you recently purchased the bike I recomend getting a shop manual, I have the Haynes,its great.

[Red01]

Hmm how easy is this changing the needles??

Pretty easy! You can change the needles without taking the carbs off the bike. The following pics show 2G carbs, off the bike.

Remove the cap of the top of the carb.



Make sure you don't loose the little o-ring (not sure if the 1G has these, but the 2G does and you NEED them, if your carbs came with them).
(Diaphragm/slide shown removed for clarity)



Remove the diaphragm/slide assy from the carb body.



Then pull the cap off the needle. (The gray part in the needle pic posted earlier.) The needle can then be dumped out of the slide.

Stock needles on US market bikes have only one clip groove, so the only way to adjust them is up, with washers. Some other markets, as well as all aftermarket needles have multiple grooves, so the needles can be adjusted up and down.

What does it do, and how can you tell what their set at?

Assuming your main jets are correct, select best needle clip position to get the best power at full throttle / 5k-7k rpm.

If the engine pulls better or is smoother at full throttle/5k-7k in a full throttle roll-on starting at <3k when cool but soft and/or rough when at full operating temperature, it is too rich in the midrange and the needle should be lowered.
If the engine pulls better when fully warmed up but still not great between 5k-7k, try raising the needle to richen 5k-7k.
If the engine pulls equally well between 5k-7k when cooler as compared to fully warmed up, the needle height is probably properly set.

Also when Jet2 is done, they test it using a Dyno, is this necessary when messing wit the needles?

Not everyone adjusts jetting with a dyno, and if whoever did yours installed the kit with a dyno, it shouldn't be honked up now. You can adjust jetting by seat of the pants - which is how everyone did it before dynos became relatively commonplace.

Check out this link for carb tuning:

http://www.factorypro.com/tech/carbtune,CV,high_rpm_engines.html