jetting for fe450 2005

Hi Tolis,

welcome to the UHE you will find it very interesting and informative, yes we can help but can you tell us what set up you have at the moment
MJ, PJ, Needle code clip position etc...

Regards

Sparks.

In Australia at sea level up to 1000mtrs with a race muffler we use a 45 pilot, needle on the 6th position(from the top) and178 main and this gives good power and no backfiring/popping on deceleration. alot have a tendancy to run the carby a bit lean at the bottom for some reason? Hope this is a help.
Regards
SMCS

it's the needle ... the needle code , that is a critical item , OBDVR

OBDVR is the one I use.

Why do a lot of people think that blue header pipes and popping on the over run is a lean condition this is totally accepterble to a degree, but you will only get the popping sinario on a open race can not on the standard enduro can unless you have air getting in the system.

SMCS all I can say is you must be one of beleivers that the standard factory settings are the dogs balls far from it.

Regards

Sparks.

yeh! like sparks says!

who wants a 178MJ anyway?

regards

Taffy

Well over here that jetting works best! Don't have ago at me when all we are doing is giving someone advice to help with a problem, I know jetting is different in other parts of the globe but the settings given work down here. If you have someother great theory fine, you run with that but I know my Bergs will still be running in years to come and have been since 1995.
Best Regards
SMCS

Taffy said:

yeh! like sparks says!

who wants a 178MJ anyway?

regards

Taffy

Click to expand...

I am using a 155 MJ in my FCR41mm on a '03 FE400
Runs great
I think I will test a 150MJ soon because you guys (sparks and yourself) say a leaner MJ will improve the starting?

ElSnorro, the main jet will not have any bearing on how well the engine starts hot or cold, but if you have hot start problems this could be an indication of a over rich idle or pilot curcuit.
What code needle are running with that 155MJ?

Regards

Sparks.

starting warm is dictated 90% by the needle straight which is the third letter in your needle code. the MJ has a really tiny knock on effect and same with the PJ.

regards

Taffy

Confused

Hi, I am confused with differing opinions on the forum. I live in Sydney Aust. In summer humidity is probably average 60-80%. In theory (please correct me if I'm wrong) the higher the humidty the less oxygen there is in the air, therefore jetting should be on the leaner end of the "opinion spectrum" and in England where the air is generally cooler (and thinner) you would assume jetting would be on richer side? I have a FE450 and it starts OK on choke cold but is a ***** to start hot (even with hot start). The bike runs great once started and is a pleasure to ride.
I have a OBDVR needle 178 MJ 40 Pilot and I assume 85 is the PAJ?????..... Don't be too hard on me I'm still learning.
Could someone give me a suggested starting point to assist in starting hot.
Thanks in advance.

RE: Confused

Sir Speed, how's things down under? I have"nt a clue what bike we are dealing with,450,550 , or 650,but I"ll take a wack at this.... being the new owner of a new 07 fe450e I had the same problem here in California, USA. Jetting is way too rich... 40p not bad, OBDVR could be richer needle but will work in the 5 or 6 clip pos., 175m is most likely the problem...drop at least 10 to a 165 for starters, maybe even smaller depending on engine size...this should help a bunch.

RE: Confused

Sir Speed... I apologize for my stupidity... Fe 450..DUH!!! I popped a 160 main in and the 450 rips!

RE: Confused

speedway

you need. as ragman says, a smaller MJ. a 165 is tops wherever you live. i would say that alone will do the job. the needle may need dropping one afterwards.

regards

Taffy

Re: Confused

speedwaydude said:

Hi, I am confused with differing opinions on the forum. I live in Sydney Aust. In summer humidity is probably average 60-80%. In theory (please correct me if I'm wrong) the higher the humidty the less oxygen there is in the air, therefore jetting should be on the leaner end of the "opinion spectrum" and in England where the air is generally cooler (and thinner) you would assume jetting would be on richer side? I have a FE450 and it starts OK on choke cold but is a ***** to start hot (even with hot start). The bike runs great once started and is a pleasure to ride.
I have a OBDVR needle 178 MJ 40 Pilot and I assume 85 is the PAJ?????..... Don't be too hard on me I'm still learning.
Could someone give me a suggested starting point to assist in starting hot.
Thanks in advance.

Click to expand...

Speedway,

I would also like to toss in my two cents here. I would recommend that when you get the chance, click on Taffy's name and use the all posts option, look at those posts he has made in the fuel sections. He has posted by far the most information about jetting.

For starters concerning atmospheric conditions and their effect on jetting. The cooler and drier the air, the leaner your bike will run as the air is denser, and there is more room for the oxygen molecules. As well, the lower the elevation, the leaner your bike will run as the air will be denser due to higher pressure.

And by denser, I mean that for a given volume of air, the oxygen molecules are packed more tightly together, IE more oxygen available to burn the fuel. And visa versa.

The hotter and wetter the air, the richer the bike will run as the air is less dense, and there is less space for the oxygen molecules in a given volume because there's a bunch of water in there, and the higher in elevation the richer it will run, because the air is less dense. Here's a great site with a calculator for you to play around with to illustrate the point. http://wahiduddin.net/calc/calc_da.htm Just plug in some data from different weather stations in your general area, and the other info requested and you'll see. Use the engine tuners calculator tool as well and it will clearly show the drop off in performance as well. Pilots have had to deal with this forever, in determining take off distances and rates of climb, especially in normally aspirated engined aircraft.

Concerning your problem: Unless you have changed your pilot air jet (paj) it should be 100, and your Main Air Jet (maj) should be a 200. Don't worry about those jets at this time.

It would also be helpful to know what clip position you are running on your DVR needle, and how many turns out you are on your fuel screw. Also, your elevation and temperture of where you are riding. And clip positions are numbered from top to bottom, position #1, is the top or leanest position, and pos #7 is the bottom or richest position. Like Taffy said, the needle straight is 90% of warm starting. However, the clip position has an effect, as it moves the straight section in the emulsion tube.

Also, make sure you have not got the idle set too high, this reduces intake signal and can make starting hard too. Idle speed should be around 1500 rpm. Just covering all the bases here to make sure we are on the same page.

Here's a rule of thumb for setting the fuel screw. First, when the bike is cold and not running, turn the fuel screw in, clock wise as viewed from the bottom, until LIGHTLY seated, note how many turns in you went, then put it back to where you had it. A good starting point would be 1 & 1/4 turns out.

Now, ride the bike around for 10 minutes or so normally. Put the bike on a stand, at normal idle Turn the fuel screw in, clock wise looking at it from the bottom until the motor starts to slow down, then back it out one full turn from there. This is a good starting point, however, you may need to adjust from this point to fine tune it.

From there, if you don't have an extended adjuster that you can turn with your fingers, turn the bike off and screw the fuel screw in again taking note of how many turns out you were so you can compare where you ended up.

Taffy likes to do what he calls the snap wheelie test. Which is something like this, with the bike warmed up, and cruising along in 1st gear at about 3mph or so, whack the throttle open and see how it responds. If it bogs, open the fuel screw 1/4 turn and repeat.

You can also just try the fuel screw at different settings and see how it affects the responsiveness of the throttle. If you find that while riding, on opening the throttle at low speeds, it burbles at little bit, turn the fuel screw in, if it feels a bit too abrupt, try turning the fuel screw out.

As the others have said, you do need to drop that Main jet down to a 160 or 165.

Get back to us on the needle clip position and the fuel screw turns.

I almost forgot, keep good notes on your changes and what effects they had or you'll end up chasing your tail.

You are now starting your journey down the rabbits hole......... But there is a light at the end of the tunnel, and it gets brighter the closer you get!

Hope this helps,

Thank you everyone for the input, it is very reassuring to see how much knowledge is tied up inside the forums.
My clip position was 5th from the top and mixture screw 1.5 turns out. Temperateure average at this time of year 25 deg C. Elevation probably 200-1000 metres.
Everything is as I bought the bike. Plug was quite black but I appreciate that can be from a number of things.

Re: for taffy

tolis said:

today my friend i have all the jets and i start the carb mods so 1) main 160
needle ocdms on 2 clip . pilot 38 . paj 60 1/2 turn . pas 1 3/4 open end the bike don't start with cold start button or not . help please

Click to expand...

Hi Trolis,

I would say your answer is lack of gas, is the carb bowl filling up?. I am running the exact same setting as you and can guarantee it's starts 1st 2nd kick everytime.
In the warmer weather I don't need the cold start button, 20C+.

Regards

Sparks.