Jetting question

Jasper · Post by **Jasper** » 03:46 pm Jun 28 2016

I have placed an other exhaust pipe on my 91 kdx
Allready have boyesen power reeds 607, 45 pilot and 155 main jet
It runs good but not like it should be
My needle is at the 4th groove, when i put it in 5 or 3 its not ok
Do you think that when i put the 1173 needle( 427-48bgp) in groove 3, like they say on justkdx it will be better?
But when i put the 1173 in groove 3 instead of the 1172 in 2, then it will run leaner? Or am i wrong?

Post by **Julien D** » 05:36 pm Jun 28 2016

Actually, the 1173 in position 3 will be a touch richer throughout most of the throttle range, other than 0-1/8, when compared to the 1172 in position 2. You're counting top down, so as you drop the clip to raise the needle, you allow more fuel through the jet needle.

BGN is 1172
BGP is 1173

Using the BGN needle in clip position 2 as the baseline, here is what the comparison to the BGP in position 3 looks like.

: kawneedle.JPG (123.95 KiB) Viewed 6885 times

Jasper · Post by **Jasper** » 12:09 am Jun 29 2016

I thought the 4th groove is the second to last, to raise the needle

Post by **Julien D** » 12:23 am Jun 29 2016

Right, sorry. I was just comparing the 1172 in 2 and the 1173 in 3. I think maybe I'm not quite understanding how you phrased your question. I'll give you this, though. Needles can be a very personal decision. Grab a couple and try them out. For an e series, start with a CGK and DGK.

Jasper · Post by **Jasper** » 07:40 am Jun 29 2016

Ok thanks will try that, btw what "program" is it that you are using?

Post by **Julien D** » 07:42 am Jun 29 2016

JDs jetting spreadsheet. Very handy.

Jasper · Post by **Jasper** » 08:35 am Jun 29 2016

Is this for free or where to find it
Or can you send a copy by email?

Jasper · Post by **Jasper** » 08:46 am Jul 05 2016

Fitted the dgk needle in second position in combination with 45 and 155 jet and i like it very much, very smooth power delivery
Maybe a little rich but i need to drive it a little more

Post by **Julien D** » 09:07 am Jul 05 2016

The DGK will be a bit richer overall when compared to the 1172/73, so you may need to lean out the MJ and PJ just a step or two.

Jasper · Post by **Jasper** » 01:47 pm Jul 05 2016

Yes but when i rode it with the 42 and 152 it hesitated sometimes and when i closed the throttle at high speed it was like whom.... Whom....whom... Never heard it before

Post by **Julien D** » 10:09 pm Jul 05 2016

Well, for the record, closing the throttle at high speed on a 2t is bad practice. Drop the throttle, pull the clutch, and use the brakes. 2t's don't like engine braking.

C George · Post by **C George** » 04:31 am Jul 08 2016

Julien D wrote:Well, for the record, closing the throttle at high speed on a 2t is bad practice. Drop the throttle, pull the clutch, and use the brakes. 2t's don't like engine braking.

Basically just shuts off the lubrication it gets from the fuel mix :( ,,, not good.

Jaguar · Post by **Jaguar** » 03:14 pm Jul 08 2016

somethings off for it to make strange noises when you close the throttle at speed. maybe a bad crank seal.

Jasper · Post by **Jasper** » 06:22 pm Jul 08 2016

Yes i know i cant engine brake with a 2stroke, it has something to do with my jetting
Today rode with the 42 and 155 dgk needle in the middle at 22degrees celcius at around 200 feet
It goes hard when i go full throttle but when i go to 6th gear it was like baaaaaaah and not the paaaah like the other gears... Suddenly a loss in power
Btw the 2stroke jetting is completely new to me
Compression is still good 185psi

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