OBEKR vs JD jetting blue or red needle

Hey Guys

My 2005 fs 650e was jetted like this: outside temp 40 -90 degs fer. 200ft above sea level

Main jet #185
starter jet #85
MAJ #200
Idle air jet #100
pilot jet #42
air screw 3 1/2 turns
JD red needle 5th clip
acp pump still connected.

The bike ran great but it has getting harder and harder to start. the idle last summer was an issue as when the engine was cold it would'nt idle so you turn it up manually and when the engine was hot the idle was way to high. I solved this problem by turninh the air screw out 1/2 turn but at the end of the summer i found myself turning the idle up again. when I took the bike apart for the winter I noticed the carb needle was slightly bent?

I have a JD jetting blue needle and a OBEKR needle. I've read good this about the OBEKR needle and was wondering which needle I should use. From what I've also read, my main jet is way larger than stock and larger than what others are running. This is what I was thinking of trying.

Main jet #170
starter jet #85
MAJ #200
Idle air jet #70
Pilot jet #40
air screw 1 turn out ?
OBEKR needle 4th clip

Tell me what you think: any help would be appreciated

Regards Dave

Hey Berger.

I check my valves every 15-20 hrs


Hey Bushie. are you saying I should drop my MAJ to something like 190? and go with a 170 main.



Thanks for the advise

Thanks Bushie

I have plenty of jets lying around that are the same dimension as the MAJjets so I will drill them out to the appropriate size.

This will be my new starting point.

Main Jet #170
MAJ #170- 172
pilot jet #40
idle air jet #70
OBEKR neddle 4th clip maybe go to 5th
air screw 2 turns out.

It's going to be 23" F tommorow so I don't think I will be doing any testing. Hopefully it's going to warm up soon

Hey Birdwood

You are correct that I'm going leaner on my pilot jet but I'm also dropping my idle air jet which would make it richer.

I have done tons of reading on this subject and I have found that there's are 2 different ways of thinking when it comes to tuning these carbs. One way is like you said, Go bigger on the jets if it's too lean, and the other is to go smaller on the jet size but smaller on the air jets as well.

I am used to tuning carbs that don't have air jets so you're method of thinking works, Go bigger. I'm trying to figure out if that's the proper way to go. There are tons of knowledgeable people on this site that say the best way is to tune these carbs is to drop the air jets which makes sense, if you drop the air jets it will richen the system.
I have owned this bike for over three years now and have put 25000kms on it, to which I never had to do any sort of adjustment to the carb. It was only last summer that I had to start playing with the air screw. So now while I have the bike apart for the winter It's a great time to tackle this problem.

Thanks for the insight though, any type of information is always useful. Like my dad always said: It's a waste of a day if you didn't learn something new.

Regards Dave

Good Point Birdwood about the motor being tired. I just replaced my piston as the old one had 300hrs on it and I was getting blowby out the tailpipe at the end of the summer So that could have been why I had to keep adjusting my Idle. Even though it was way to cold to ride this weekend I bench tested my bike in the garage With:
Main jet #170
Main Airjet #180
pilot jet #40
idle air jet #70
OBEKR 4th clip
air screw 2 1/2 turns

The bike started right away and idled. After making some adjustment, It idles at 1800rpms but the air screw is out 2 1/2 turns so I will go with a larger pilot maybe a # 42 or a #45

Thanks Dave