[thedevilman]

Today I had the dealer down jet my sled from 520N to the old style 500 jet sizes. has anyone tried this and if so did it help the rich condition these 800's are known for....Also I have the Boyesen reeds installed.

 

[FINNBEAR]

I heard installing reeds can lean out your engine because provides more air, which provides more performance !

 

[Gunner]

Actually, Boyesen says to jet down when installing
their reeds.

Who has an 02 800 with EGT guages? I would like
to know what you are running for temps with 500's
at WOT.

The 01's you could go to 470's and be fairly safe
with the stock head.

That's a big difference with just a small pipe change from the
01 to 02. Are there any other changes?

I don't know about you, but I've had a heck of a time
reading the wash on these twins and the plugs don't
change an awfully lot either. Yes, I can get them
chocolate brown, but change another jet size and they
still look very similar - especially with the RK Tek head.

 

[800x2002]

500's were running 1220 at -20F for about a 2 mile run last week. Stopped and checked the plugs and they were perfect!!! I was surprised that both cylinders were within 5 degrees. It was the best the sled ran yet tho I still had flames out the exhaust at that temp too!!!!

 

[MXZ X 800]

Asked my dealer about the jet issue. They have tried many diffrent combos. and did not get any more hp on the dyno.
This was with just jets nothing else. I do not have spacific sizes but the guy that does all the tweekin for them has all the money and parts he wants. The owners has very,very,very deep pockets.

 

 

 

[blk800]

Hey gunner whats the coldest you went with 480's?

 

[Gunner]

-25 F in canada one time. No problems. I did make
sure I blipped the throttle and didn't hold it WOT
for a long period of time. It was too cold to change
jets.

 

[bonzi]

Just got back from Colorado with my 02 HMX and with a RKTech head and restrictor in the pipe I ran 430 mains with all the foam removed (still to rich)  a 9HIY1-52 needle in the #2 clip, picked up millage (about the same as a 670) and performance. I had my stutter box set at 1,200 degrees and never set it off. I have not had the January update done yet but will before going out west again. Altitude was 9,000 to 11,000 ft and temp was -15. I feel that 410 mains will be about right. If the filters are put back in even lower mains are possible. So start with all filters in place and remove one at a time while testing.