Comments on Dynojet stage 3 for GS1100/1150

[Mikael]

Hi !
Last year I purchased a GS1150 that was equipped with pod filters and a pipe.
The bike runs fairly well, accept for the throttle respons that is a bit sluggish.
The only jetting change done on the carbs seems to be size 125 main jets.

However, trying to do things right I have now bought a Dynojet stage 3.
What makes me puzzled though is that the kit comes with DM175 main jets.

Questions:
1. Are these jets really 175 in size, or is that a different numbering ?
2. If so, does anyone have experience from this kit ?
(I my opinion it sound like the bike would run way to rich.)
3. Is it possible to only install parts of the kit. I was thinking of changing
the needles, drilling the slides and maybe fit a slightly larger main jet.

Thanks Mikael

[RacingJake]

I have a Dynojet kit #19-3133 for my 82 GS1100. It comes with 4 sets of main jets- 110, 114, 132 and 138's. It also has a DH 160's and those are for the pilot air jets. If you play around with the fuel metering then at some point you start with the air too.

On my kit the pilot air jets are DH160's and are optional to use. Using them they are suppose to lean out the bottom end.

Hope's this helps

[Jeff Tate]

Don't try and out guess the kit manufacturer. They spent alot of time getting things in the ballpark. Even installing the complete kit can be a jetting headach when things are done right. I spent aloooong time tinkering with the jet needles and the washers that go on top and under them and also the mixture screws. It's not really hard to do but very time consuming. You'd be surprised at how much richer the carbs have to be with pod filters. I can't say much about the main jets you have but it's better to start on the rich side instead of too lean.

[KEITH KRAUSE]

I'm glad you got the jet kit and will be richening the needle circuit,etc. The needle circuit is where you spend the most time riding. With pods and a pipe and only a main jet change(that sounds too small) you have been running WAY too lean. When you get it right you will see how much better the bike runs. Lots of help here with jetting if you ask.

[Anonymous]

What color are your spark plugs right after a normal ride. If they are not too far off maybe just a couple of washers on the needles will do the trick . Don't even have to remove the carbs most of the time to do that.

[Mikael]

Nicely put Jeff. Maybe I was trying to out-smart the manufacturer. My concern
though, is that the kit looks like it was designed for a highly tuned bike with
an open pipe, and not a stock motor with a fairly restrictive pipe, like mine.
And that installing the kit would make me go from too lean to overly rich.

The bike was in a sad condition when a got it, and I have had most things
overhauled. The carbs was cleaned out and set to factory specs, (except for
the main jets). Test driving revealed that the bike was running lean, so I have
gradually richened the idle circuit and raised the needles so that it runs ok.

I agree that it is possible to completely mess up fuel metering if one isn't careful
when making changes. I also agree that it takes so much effort to get it right.
My idea therefore was to alter the carbs in three steps:

1. The bike is running lean at open throttle.
=> 135-140 main jets would fix this.

2. The bike is still running lean at part throttle, (with stock needles in top position).
=> The Dynojet needles would hopefully correct this.

3. Throttle respons is a bit slow and sluggish.
=> Larger holes in the slides, like the kit describes, can help with that.

More comments are welcome / Mikael

[KEITH KRAUSE]

Nicely put Jeff. Maybe I was trying to out-smart the manufacturer. My concern
though, is that the kit looks like it was designed for a highly tuned bike with
an open pipe, and not a stock motor with a fairly restrictive pipe, like mine.
And that installing the kit would make me go from too lean to overly rich.

The bike was in a sad condition when a got it, and I have had most things
overhauled. The carbs was cleaned out and set to factory specs, (except for
the main jets). Test driving revealed that the bike was running lean, so I have
gradually richened the idle circuit and raised the needles so that it runs ok.

I agree that it is possible to completely mess up fuel metering if one isn't careful
when making changes. I also agree that it takes so much effort to get it right.
My idea therefore was to alter the carbs in three steps:

1. The bike is running lean at open throttle.
=> 135-140 main jets would fix this.

2. The bike is still running lean at part throttle, (with stock needles in top position).
=> The Dynojet needles would hopefully correct this.

3. Throttle respons is a bit slow and sluggish.
=> Larger holes in the slides, like the kit describes, can help with that.

More comments are welcome / Mikael

You say you have raised the needles, but then you say the bike is running lean with stock needles in top position. ? You need to install the jet kit needles and (to start) put the E-clip in needle groove #3 or #4 from the top and test.

[Mikael]

Just making sure that we don't misunderstand eachother:

Raised the needles =
Putting the clips in a lower position on the needle

Running lean with needles in top position =
Running lean with clips in lowest groove on needle.

/ Mikael

[Anonymous]

dynojet kit questions

I installed the dynojet kit in my 1150 stock with GSXRexhaust and K&N filter (no airbox) about 5 years ago. It took some fiddling but its working great now.
Dynojet uses their own numbering system that is not compatible with Mikuni.
Use the whole kit. Its a system designed to work together and has been developed as such.

My experience...
I started with the stage 3 jets and needles in 3rd groove. worked well but used about 25% more fuel.
Then moved to stage 2 mains-still ran great and got better gasmileage.
Then finally I moved the needles up a notch so that the needles are down (leaner) and installed tiny spacer washers so in effect the needles are only lowered half-a notch.
The gas mileage has improved to better than stock.
The idle was a bit lean so I have turned the idle mixture screws out 2.5 turns.
Since then I've installed a 1230 wiseco kit - still runs great. and more recently a 1200 bandit exhaust and RF900 can. No change to carburetor settings-still runs great and gets even better gasmileage than stock.
About 2 years ago I went back to stock mikuni jets and needles as a test. couldn't believe how much less responsive it was a low speeds.
suzookeeper ger

[KEITH KRAUSE]

Just making sure that we don't misunderstand eachother:

Raised the needles =
Putting the clips in a lower position on the needle

Running lean with needles in top position =
Running lean with clips in lowest groove on needle.

/ Mikael

That's right. I understand how to adjust needles.
Your way of describing just throws me off a little. For example,"running lean with clips in lowest groove on needle". This would actually be the richest you can set the needle. I would try the clips in the 3rd groove down.

[Jeff Tate]

Here's a link to a web site that may be of help to anyone that can use it.

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

[Jeff Tate]

I also found this diagram that might be helpful.

http://www.carbparts.com/mikuni/mikuni_tuning_info.htm

[Mikael]

Thanks everyone, this is really helpful. So going back to my initial questions.

1. No! Size 175 Mikuni jets are not equal in size to Dynojet DM175.

2. Experience from this kit: It might be bit on the rich side, otherwise it works just fine.

3. I hear you: Just use the hole kit.

Sorry Keith, I wasn?t trying to be smart or anything.
You made a correct description of my problem. The needles are in their richest
position, and the bike still runs lean. So I am actually out of options using the
stock needles and I am therefore considering the Dynojet ones instead.

Interesting:
How much modification is needed to make the Bandit exhaust and RF can fit?

/ Mikael

[KEITH KRAUSE]

Thanks everyone, this is really helpful. So going back to my initial questions.

1. No! Size 175 Mikuni jets are not equal in size to Dynojet DM175.

2. Experience from this kit: It might be bit on the rich side, otherwise it works just fine.

3. I hear you: Just use the hole kit.

Sorry Keith, I wasn?t trying to be smart or anything.
You made a correct description of my problem. The needles are in their richest
position, and the bike still runs lean. So I am actually out of options using the
stock needles and I am therefore considering the Dynojet ones instead.

Interesting:
How much modification is needed to make the Bandit exhaust and RF can fit?

/ Mikael

mikael, I never thought you were trying to be smart or anything. We just use different terms I guess. Part of the confusion was you say you were adjusting the stock needles. Maybe I'm wrong but aren't the stock needles NON-adjustable? If so, then you will never get the jetting right. With your mod's, I would try the Dynojet needle with the clip in the 3rd groove down with a jetting spacer on top( technically,this will put you right between groove 3 and 4) and the smaller of the (2?) main jet sizes they give you.
You will also have to adjust your mixture screws out a little, maybe 1/2 turn? Just for starters?

[Anonymous]

dynojet kit

I agree with Keith on the initial setting.
Perhaps some countries got different carb arrangements but in Canada the idle adjustment screws are adjustable and the needles come with 5 grooves in them.
The dynojet needles are a completely different shape than the stock needles.

The Bandit 12 exhaust required a lot of modification. They had to be bent slightly to allow clearance under the oil pan. New flanges had to be made to allow the bolts to line up. I used the stock GS aluminum flanges and they had to be machined to allow clearance around some allen screws in the pipes. The RF can bolts right onto the Bandit pipe. If I knew how to post a pic I would include one. haha
suzookeeper Ger