yet another 550 jetting thread

[jzfe]

Hi HusaGuru's, I wanted some input on jetting a 550. It ran good no matter what jets I tried(stock, etc.), but would like to here from more experienced jetting technicians.

Altitude 8-12k feet
pj 42
paj stock
mj 165
maj stock
NCVS needle clip 4
fs 1.5
honda AP diaphram
FP emulsion tube

Basically Buzzard's set-up. Runs great! Can I do better? After quite a bit of testing today, it is all starting to feel the same when riding, better than stock... Yes I read the DOC and forum searches. The DOC does an excellent job of explaining all the nuances of the FCR, but without a wideband o2 or a dyno, real changes are hard to note. Its seems these bikes run good no matter what you do, very forgiving. thanks gents!!


jz

 

[buzzard]

Contact DaleEO for any further jetting and set up tricks on the 550. He has done a lot of research on the 550. We have a 550 in Montrose jetted just like yours, and like it a lot..

 

[DaleEO]

Hi HusaGuru's, I wanted some input on jetting a 550. It ran good no matter what jets I tried(stock, etc.), but would like to here from more experienced jetting technicians.

Altitude 8-12k feet
pj 42
paj stock
mj 165
maj stock
NCVS needle clip 4
fs 1.5
honda AP diaphram
FP emulsion tube

Basically Buzzard's set-up. Runs great! Can I do better? After quite a bit of testing today, it is all starting to feel the same when riding, better than stock... Yes I read the DOC and forum searches. The DOC does an excellent job of explaining all the nuances of the FCR, but without a wideband o2 or a dyno, real changes are hard to note. Its seems these bikes run good no matter what you do, very forgiving. thanks gents!!


jz

Hi Jz,

Yes you can do better, at least I'm pretty sure you can.

I'll give you some suggestions here but let me know what kind of riding you are doing at 8-12K. I see that it is supposed to be between 49 and 80 degrees for the next several days so I'm going to assume those are the temps you are riding in.

By the looks of things I'd say you are still pretty rich for that altitude and also with the high humidity as well.

You might give these settings a try:

NCVS @ #3.
main jet: 158
pilot jet: 38

Try the 38 pilot first and see if you're in range on the pilot screw-- between 1 & 3/8 to 2 & 1/2 turns out. Be sure the bike is warmed up fully, at least 15 minutes of riding around. Turn the pilot screw in until the motor just starts to slow down, then back out one full turn. This will give you a good starting point for the pilot screw. If you end up under 1 & 3/8 turns out try going to a 35 pilot.

Have a look at the jetting chart here: http://www.husaberg.org/index.php?full= ... _photo.php

You will notice that I suggested two jet sizes smaller than what is in the chart. This is due to the increased intake impulse of the larger motor through the same size carb as the 450R Honda. That's kind of a rule of thumb, and it is usually very close to perfection.

Now you will be able to use this chart as the weather or your altitude changes. I went with the 59-80F range and 7500-10000 feet settings for my suggestions to you since your riding area goes a bit higher, and it's pretty humid there.

I think with these settings you will find that power band is wider, and it will pull really strong from the low end.

If you have any questions feel free to ask.

Dale

P.S. Thanks for the props Buzzard!!

 

[Taffy]

You will notice that I suggested two jet sizes smaller than what is in the chart. This is due to the increased intake impulse of the larger motor through the same size carb as the 450R Honda. That's kind of a rule of thumb, and it is usually very close to perfection.

be careful dale

you haven't taken into account port dimensions or valve sizes let alone the cam grind. fuelling is all these and the HP it puts out as well and the 450 puts out a lot!

real life testing is where you'll find the answers and not on the maths table. we don't always have the full picture and so make surre your tests bear all your calculations out.

i'm not saying you have the wrong answer but that how you got there isn't the right route.

regards

Taffy

 

[DaleEO]

You will notice that I suggested two jet sizes smaller than what is in the chart. This is due to the increased intake impulse of the larger motor through the same size carb as the 450R Honda. That's kind of a rule of thumb, and it is usually very close to perfection.

be careful dale

you haven't taken into account port dimensions or valve sizes let alone the cam grind. fuelling is all these and the HP it puts out as well and the 450 puts out a lot!

real life testing is where you'll find the answers and not on the maths table. we don't always have the full picture and so make surre your tests bear all your calculations out.

i'm not saying you have the wrong answer but that how you got there isn't the right route.

regards

Taffy

Thanks for the input Taffy,

My suggestions for the jetting for the 550 in comparison to the chart I referenced are from real life testing results @ 8500-9800' msl and 68-80F, confirmed by at least two others who also did a fair amount of testing with an 07 550, and in this case, at the same altitude as jzfe.

My suggestions are, I feel still a tad rich on the main, so I was being a bit conservative there, as that is what I was running last summer at the previously mentioned altitudes. And I also took into consideration my recent change to a 38 pilot for altitudes much lower than that, with the NCVS needle @ #3, once I had discovered my vacuum release plate O ring was leaking a bit. JZFE will have to test out my suggestions and see what he thinks. My hunch is that he will be able to go leaner still on the main, and perhaps go to the NCYS @ #2 which is a half clip leaner than the NCVS @#3. I was going to wait to make that suggestion until after he got back to us with some testing results, if he tried my suggestions.

 

[Taffy]

RE: Re: yet another 550 jetting thread

well i like the way you're going and its good to see people working down to 38s. don't forget that i was on my own there till sparks dived straight in last summer and joined in.

but you did compare the honda to the husaberg even though you then say you based it on rides. for instance if what you said was true, my 400 would be on a 160 and your 550 on a 155 etc etc which patently isn't what happens.

tricky old business jetting!

regards

Taffy

 

[DaleEO]

Re: RE: Re: yet another 550 jetting thread

well i like the way you're going and its good to see people working down to 38s. don't forget that i was on my own there till sparks dived straight in last summer and joined in.

but you did compare the honda to the husaberg even though you then say you based it on rides. for instance if what you said was true, my 400 would be on a 160 and your 550 on a 155 etc etc which patently isn't what happens.

tricky old business jetting!

regards

Taffy

Right!,

It is a tricky business but, as you told me on a thread, just devote time to testing, and it will be fun. And you were right, it was fun, especially when you start making changes and keep notes and it eventually leads to a logical conclusion, and the improvement you were looking for. While other bikes, and jetting spec's tend to be a bit anemic at high altitudes and warm temps, with the changes I have made, the bike is crisp and very responsive in these conditions. In fact, with the right flick of the wrist it is rather explosive when you want it to be. Having the ability to seat bounce over seveal whoops is great, but, the bike still has great low speed manners.

You just have to put the time in doing the testing. Yes, I did compare the Honda and the Husaberg, but, only for the purpose of relating the Husaberg to the Honda chart so that one could just plug in what they were using, or overlay it at a given point and have the chart there to make adjustments for temp, and altitude. Sorry if I came off incinuating that one could just make this a hard fast rule.

So far, it has worked out really well for me. The only change left for me to make when I have the time to devote to it, will be to go to the smaller paj to smooth out the transition from closed to just opening the throttle, and as I said in another thread, the last time I tried to pull the paj it was stuck so I will need to have an extraction set at the ready when I get ready to change the paj.

JZFE, Have a look at this thread when you get the chance. http://www.husaberg.org/index.php?name= ... 5778#75778

The above linked thread is my the result of my ongoing search to get rid of the rich stumble that comes in when the bike is ridden slowly on technical trails for a long time and starts to get hot.

One other thing JZFE, Buzzards friend Brett rides an 07 550, and is running the NCVS @ #3, 40 pilot, and a 158 main. But as I have indicated, I think the 38 is the way to go, you'll just have to do a bit of testing there and see how it works out. Just remember, if the bike still runs at idle with the pilot screw turned in all the way the pilot is too big.

 

[jzfe]

RE: Re: RE: Re: yet another 550 jetting thread

WOW, that is way leaner than I thought could be run without getting combustion temperatures unacceptably high. Thanks for all the info and discussion on the subject. I will continue testing this weekend. thanks again!! :bow:

jz

ps. fritz already sold my 450, and the 550 is completely AWESOME!!!!!!!! :greenjumpers:

pss I changed my signature in my account, but it did not show up on screen

 

[bigbob]

RE: Re: RE: Re: yet another 550 jetting thread

you have to change your signature at another location in your control or account page. thats all I can add to this very very good jetting thread

 

[Taffy]

RE: Re: RE: Re: yet another 550 jetting thread

i had someone ask me about the EKR DVR last night and i thought i'd mention here that the needle straight is too fat. you get a stumble when moving off, nowhere else, just moving off.

in the doc it does say EKQ. even a P but they tend to eight-stroke when warm and in the USA and our summer would be a pig to start after a fall. this is not the same bog as the many others that you can get (rich, lean, needle clip etc) so i would ask anyone who wnats to get their jetting right to get athe correct D or E series recommended in the doc. or the honda series which i have yet to test.

regards

Taffy

 

[sparks]

Re: RE: Re: RE: Re: yet another 550 jetting thread

I run the same jetting as DaleEO apart from I have got rid of the ridiculous AP pumper, this in my opinion is giving that hick up just off idle.
The main reason the AP is switched on is because of the lean PAJ #100, change this to a adjustable one set at around 1/2 a turn out or a fixed jet #60#65 and the pick up will be just about perfect.
And turn off the AP.

Regards

Sparks.

 

[jzfe]

RE: Re: RE: Re: RE: Re: yet another 550 jetting thread

Ok HusaGuru's, the results....a 38 pilot performs as described here by Dale and in Burned's forum(sticky) on TT. Turned all the way in it stalls the motor. This seems to be the best pilot ckt test. I left everything else the same. One change at a time eh? Well, now I'll ride it for real(trail ride) and go from there. :rock:

jz

 

[DaleEO]

Re: RE: Re: RE: Re: RE: Re: yet another 550 jetting thread

Ok HusaGuru's, the results....a 38 pilot performs as described here by Dale and in Burned's forum(sticky) on TT. Turned all the way in it stalls the motor. This seems to be the best pilot ckt test. I left everything else the same. One change at a time eh? Well, now I'll ride it for real(trail ride) and go from there. :rock:

jz

So, where did you end up setting the ps?

Did you ride the bike around for 15 minutes or so before you messed with the ps? It will be interesting to see what your ps setting is after you have got the bike really heat soaked on a long trail ride.

And good choice on making one change at a time, be methodical. The pilot jet, along with the proper ps setting will really improve your closed to 1/8th open throttle as you roll it open.

IMHO, the next change I would make is to try dropping the needle to #3, I think you will be pleasantly surprised when you roll it on, smooth and strong.

Then try dropping the main jet.

Glad to hear that it's going as planned so far.

 

[jzfe]

RE: Re: RE: Re: RE: Re: RE: Re: yet another 550 jetting thre

Sorry I was not more specific. I road it hard for a little over a mile, several hard accelerations through all the gears(10 maybe 15 min). I then turned the fs screw in all the way and it slowly died(5 seconds or so). I backed it out to 1 3/4 turns and rode again around the block(more like hill, my driveway). I was going to fine tune it when I ride hard on the trails tomorrow. It seems smooth and crisp, still starts one kick, booyea!

 

[DaleEO]

Re: RE: Re: RE: Re: RE: Re: RE: Re: yet another 550 jetting

Sorry I was not more specific. I road it hard for a little over a mile, several hard accelerations through all the gears(10 maybe 15 min). I then turned the fs screw in all the way and it slowly died(5 seconds or so). I backed it out to 1 3/4 turns and rode again around the block(more like hill, my driveway). I was going to fine tune it when I ride hard on the trails tomorrow. It seems smooth and crisp, still starts one kick, booyea!

Thanks for the clarification. Sounds like you are on your way!! Keep us posted with your results.

Dale

 

[jzfe]

RE: Re: RE: Re: RE: Re: RE: Re: RE: Re: yet another 550 jett

38 pilot works great, after a couple of real trail rides. The main/needle is still a little rich, though it runs good. I will next drop the needle a couple of clips and retest. It is noteworthy that I could easily live with this current set-up. I can sometimes stall it on trail obstacles when I open and close the throttle rapidly while crawling up ledges. Is this a rich condition? or just the rekluse not disengaging fast enough? Either way, it's technical trail manners are excellent. I rode up a tough boulder climb that mountain bikers were carrying their bikes down! I am finally making moves I would hesitate and choke on before(my issue, not the bike). Totally cool and fun!!!

 

[Taffy]

RE: Re: RE: Re: RE: Re: RE: Re: RE: Re: yet another 550 jett

a flat spot at mid revs is a little lean and you should raise the needle.

what you are doing is altering the fuel curve. you took away with the 38 but you add with the needle. you'll be suprissed how many imes things get larger only for the MJ to come down and it all starts again. if you only knew which main you were going to end up with now you could save a lot of time.

see it as a long piece of liqourice. you lower the MJ and then you can roll the rest of the liquorice down.

regards

Taffy

 

[jzfe]

RE: Re: RE: Re: RE: Re: RE: Re: RE: Re: yet another 550 jett

Well, why don't I just keep it, 38 pj 165 main? and do clip adjustments to fine tune it?

 

[Taffy]

sounds good. thats you sorted and out.....
or are you? WOULD it be better with a smaller MJ?
now you'll NEVER know....... :twisted: :twisted: :twisted:

regards

Taffy

 

[sparks]

Re: RE: Re: RE: Re: RE: Re: RE: Re: RE: Re: yet another 550

Well, why don't I just keep it, 38 pj 165 main? and do clip adjustments to fine tune it?

jzfe, like I said in my earlier posting if you want it to carburate better at small throttle openings you need to get rid of the AP and rejet the PAJ correctly, even more so with the high altitude you are riding.
I am using the NCVS on clip #2 FP atomiser38 PJ and 160 MJ and I'm at sea level, with the altitude you are at I would expect you could come down to a 155 or 150.
On the same day as my accident I did a bit of off roading on some rocky out crop loose small stones and larger ones up small football size all 1st gear stuff just to see actually how good it was at low speed off road and it was good, no hesitation of any kind and good sharp throttle response, it would either grip or just spin up the back wheel.
The altitude here was around 1500 ft.
For what it costs for a PAJ give it a try I think you might be pleasantly surprised.

Regards

Sparks.