Stock carb jets for invader 440

[tool13x]

Hi everyone, new to the forum here and I've been browsing the threads looking for information on the stock carb parts for a 79 invader 440. What a great resource, lots of knowledge and experience on this site!
I am trying to rebuild the carbs (vm36)  and I was told parts weren't available by my dealership. However I was able to find a kit online and I think I will have to buy the needles and jets separately if I can find the  srock part numbers. Does anyone have this information, and maybe a recommendation of a website to order them from?

[gixxer6]

http://www.newbreedparts.com/newbreed/

[Tory944]

 I do have the original brass hex (for the ecno/power jet 36mm) with rubber o rings (used but nice) if you can't locate any.  Also have many needle jets, needles, etc.  Let me know what you're looking for and I might be able to help.      Tory

[Tory944]

   6DH3 needles and Q2 or Q4 needle jets are general guidelines for the 36's and 38's.  There is some overlap so the motor will run fine a step up (rich) or down (lean) with any of these combinations.  Clip position w/your needles is where most of your tuning will be...

[tool13x]

Thanks, you guys have been a great help. I also found a few sites www.sudco.com and www.mfgsupply.com that both carry a decent selection of carburetor parts and jets. So we have a 6DH3 needle and a Q2 or Q4 needle jet. Does anyone know the main and pilot jet size? I found some references in other posts but I have some conflicting information. Does a 150 main jet and a #30 pilot sound right?
Thanks again.

[tool13x]

Eureeka, after much searching I managed to find a parts manual online. These are the parts listed for a 79 440 Invader:

Needle: 6DH7-3
Needle Jet: P6
Main Jet: 150
Pilot Jet: 30
Econo-Jet: 120
Float Needle Valve Assy: 1.2

So now with the needle listed as 6DH7-3 does that mean I could use either a 6DH7 or a 6DH3 needle? which one would be better with the P6 needle jet they recommend?

[Tory944]

  I don't have a manual in front of me, but if you're running the original carbs you also have a power/econo jet in the bowl.  150 mains sound about right in conjunction with your econo jets.  30 pilots are a bit small...   I'd go 35's or 40's.  This will help start ups on COLD days.  As far as the needles...  6DH7 is leaner (across the board) than the 6DH3's.  Sled will run fine with either of these.  P6 Needle Jet is leaner than a Q2 or Q4.  But again, will run fine with either.  Like I said earlier there is some overlap in tuning and you aren't going to seize up the motor with any of these.  If you like to go with the calibrations your manual recommends and you feel like you are a bit lean/rich in the midrange, just move your clip position up or down (lean/rich) on your needles.  6DH7 will work fine with your P6 needle jets.   The only thing I see from what you mentioned that I would change would be your pilots...  30 is too lean. IMO

  Needles are designed to give different fuel requirements at different throttle positions in the midrange tuning...

                 

[tool13x]

Thanks again for the info. I will take your advice and upgrade the pilot jet when I order my parts.  Hopefully all this work will pay off, after sitting for 20 years I  thought this would be the logical place to start.

[kawhead]

imo   gotta do crank seals after 20 years.

[tool13x]

Yes, I've seen that crank seals seem to be a common recommendation on these sleds. I think I will try to get it running by rebuilding the carbs and installing new plugs before I commit to the bigger job of the crank seals. Could the crank seals cause any running issues or just oil leaks?

[Tory944]

No oil leaks just piston meltdowns..... .......   

[tool13x]

Lol oh i see... well thats much worse.   I suppose ill have to move that to the top of my list. Why does it cause so much damage? Does it suck air through the faulty seals and lean the mixture out to the point of overheating the pistons?

[rminier]

Yes, you are absolutely correct about crank seals leaking air into the crankcase and causing the fuel/air mixture to go lean (HOT), and potentially melting a piston. Not sure Kawi sleds are any more prone to this than any other brand. Kawi certainly did not use cheap seals as original equipment. Any sled as old as our Kawi's, whether it's a cat or Polaris, etc. should have the crank seals replaced. The rubber carb boots are another potential source of air leaks if they have developed any cracks. You should check them closely also.
  The jet needle should be a 6DH7. The -3 identifies the stock position for the clip on the needle. There are 5 grooves in all needles. The stock recommended position is position "3", or the middle groove on the needle. That is a good starting point...you can raise or lower the needle one groove at a time to adjust the mid range air/fuel mixture.

[jimvw57]

It can also make them tough to start, and flood easy, fuel pumps may not work right, etc.  Best to replace the seals and not have to worry about it.

[tool13x]

Dammit Jim, you just described all the symptoms I am dealing with... you guys have convinced me, crank seals it shall be.
Does there happen to be a write up on replacing the seals that I havent found yet or is it pretty straight forward?
Update: I just found the "crank seals for dummies" walkthough, this site is awesome!