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    02 xc 600 improver jetting question

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    14 replies
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    • Member since
      January 2009
    • From: marathon, ny
    02 xc 600 improver jetting question
    Posted by DOOMOD 875 on Saturday, January 2, 2010 5:36 PM

    i have a 02 xc 600 that has twin htg pipes and stock head. just had it ported and were trying to jet this thing. i went from 430 main jets all the way to 530n and i'm still to lean. i even drilled the main jet out with a 1/8 drill bit and still not enough fuel. its def not a gasket or a seal leak, i checked everything twice. the sled doesnt idle funny or enything, runs great other than white, dry plugs. any help would be great

     2D-BAR racing

    • Member since
      March 2007
    • From: RS
    Posted by crippledrmk on Saturday, January 2, 2010 7:55 PM

     

    what fuel are you using??    oil   ??  

     

    USMC
    • Member since
      January 2009
    • From: marathon, ny
    Posted by DOOMOD 875 on Sunday, January 3, 2010 2:05 PM

    93. amsoil.

     2D-BAR racing

    • Member since
      July 2005
    Posted by jasper on Monday, January 4, 2010 4:14 PM
    You really need to look at your piston wash. Sometimes when dealing with a modded engine its hard to read a plug when running todays unleaded pump fuel. Either that or you have some issue with your fuel system being unable to supply enough fuel.
    • Member since
      January 2009
    • From: marathon, ny
    Posted by DOOMOD 875 on Monday, January 4, 2010 4:29 PM

    i cant kill the motor with fuel.even with the main jet drilled out. i eather lost air volacity or i"m just taking alot more air in

     2D-BAR racing

    • Member since
      July 2005
    Posted by jasper on Tuesday, January 5, 2010 8:38 AM
    I think you answered your previous post. You have some issue of fuel supply. Time to check if the fuel pump is putting out enough volume or maybe an obstruction with the fuel pickup inside the tank. Check the vent lines also for any pinching.
    Moderator
    • Member since
      October 2005
    Posted by Oneshot on Tuesday, January 5, 2010 9:23 AM

    I agree with Jasper. You should be checking your Fuel Pump. In Fact, it's probably due for a Rebuild anyways. The Kits are cheap and you can do one in less than a 1/2 hour. I assume you are still running the Stock Carbs right? Or have they been bored? Just curious is all and I was wondering, who did your Porting? Was it HTG? I used to have One of their Engines and their Porting Techniques work extremely well.

    Anyways, I'd do the Pump rebuild and then try her and even if that isn't the Problem ( and I'll betcha it is), you will at the very least  have eliminated one Possibility and can focus on another like checking the Inlet Needles/seats in the Carbs. You can buy a kit for these as well for a few bucks.

    Good Luck,

    Rob.Wink

    • Member since
      January 2009
    • From: marathon, ny
    Posted by DOOMOD 875 on Tuesday, January 5, 2010 10:09 AM

    if the fuel pump wasnt pumping good, it would run the bowls dry and quit. it doesnt do that. just lean

     2D-BAR racing

    Moderator
    • Member since
      October 2005
    Posted by Oneshot on Wednesday, January 6, 2010 8:06 AM

    That's not necessarily true however, at any rate, it wouldn't hurt to check it like Jasper mentioned. It may be working well enough to run the engine but, not to supply the proper fuel pressure.At least check and see if it's wet with gas anywhere around the outside of the Pump.

    If this isn't the Problem, check out your Air box. Make sure there are no cracks. This will make your engine suck more air than fuel obviously and it wouldn't be the first time something simple like it could be the source of the extra air and/or low fuel causing the lean condition. Just last Season my own Sled started running lean. When I removed one of the Twin Air boxes sure enough one had a big crack right by the Carb inlet. Sealed the Crack/solved the lean condition.

    Good Luck and let Us know if nothing turns up.

    Rob.Big Smile

    • Member since
      July 2005
    Posted by jasper on Wednesday, January 6, 2010 3:11 PM
    I'm assuming you have checked piston wash to confirm its lean. As far as HTG's porting. I can't say the same quality of work was done on a 660 years ago that we reworked. Must of been their first big job on those ves twins, but thats another story, and has no bearing on this issue. If your so sure its not a fuel delivery problem...what about the carbs...anything that was done to them that hasn't been mentioned.
    • Member since
      July 2005
    Posted by jasper on Wednesday, January 6, 2010 3:17 PM
    I forgot to ask since you only drilled out the main jet....just for ha ha's have you tried a richer nozzle. Perhaps the needle jet is the limiting factor.
    • Member since
      January 2009
    • From: marathon, ny
    Posted by DOOMOD 875 on Tuesday, January 12, 2010 8:06 AM

    i think the emultion tube is the limiting facter. i have p-8 tube. not shure wat size is bigger or if i need a bigger needle wen i go bigger on tube

     2D-BAR racing

    • Member since
      January 2009
    • From: marathon, ny
    Posted by DOOMOD 875 on Wednesday, January 20, 2010 1:28 PM

    drilled the tube out 2ths bigger and ran it with the same drilled out main jet. now its wicked rick and i can go back to normal jet sizes. must be around 510n main jet u cant flow any more thru the tube. thanks for all the help

     2D-BAR racing

    • Member since
      March 2007
    • From: RS
    Posted by crippledrmk on Thursday, January 21, 2010 5:18 AM

     was going to say exactley that..the nozzle/needle jet will limit fuel thru the main jet..can be confusing so take your time and listen to what the motor is telling you then think about what jet changes are doing..good luck...been there many times

    USMC
    Moderator
    • Member since
      October 2005
    Posted by Oneshot on Thursday, January 21, 2010 6:46 AM

    Jasper, sorry to hear you were not happy with HTG's work on that 660 twin. I used to own one of their O-ringed 650 Triple Piston Ported with their Pipes, bored Carbs etc. Looked at the Cylinders and while there wasn't a lot of work in either the Intake or Exhaust ports, there was an incredible amount of Aluminum removed by the Transfer Ports. Compression was super high with the O-ringed Heads etc. so she really liked her 110 Octane. The Motor was exceptionally Strong and with the Pipes they installed would rev all day at 9,800. I had a lot of fun with that Engine and won a fair bit of Class money at both Cosdra and a few Outlaw Races. When it was originally built in 96, this motor powered an Improver to 700 Imp. Stk. 96/97 Cosdra Points Championship.

    Maybe the Schoopings didn't perfect the newer Twins right away.  They semed to know what they were doing with the old Fujis though!

    BTW a Guy was wanting to now what the Stock Ignition Advance is for a 95 Storm engine on this Website so,  I steered him in your Direction. Hope you don't mind as no one seems to be able to help him out otherwise. Never owned or worked on a Storm myself. I figured you would know if anybody!

    Have a Great Day,

    Rob..Wink

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