Well thanks to another Great weather day here in the mid west (where exactly that is should be a start to a whole new thread - which I will not go into at this time) I was able to slip away and do some more Testing / Jetting to the MIGHTY 670R (rotax for those who don't know) ....

Let me start by saying I have never used EGT gagues before... (ya, ya, ya, here comes the excuses)

Well as you may know I finially got the 670 to start and idle under its own power...
(Insert here = electric start would sure be nice ....)

So I have my eyes glued to the guages and for some (yet unknown reason) the mag side cylinder of the Engine is always reading 200 more degrees than the clutch side of this rotax beast (you might tell from the tone that I'm not yet sold on Rotax Tech...)

I spend the next 4 plus hours adjusting the dual carbs every which way possible and I still see the same results ( 200 less degress on the clutch side - incase you are not keeping track)

This has me worried (woryed - confussed - whatever) since no matter what I adjust the High and Low idle to, the EGT probes keep telling me that the clutch side is COLD and the Mag side is HOT
(I do the stupid does it hurt test (place finger on exhaust) Clutch side - slight warming feeling --> <Mag side - Third degree burns (HOTTER THAN HELL) WHY...

After another 1+ hours of dicking around - I say (sorry this is a pulic formun) RATTS and lets just go for a spin....

So I throw the seat in and jump in and push the throttle and off I go...

Jetting is MOST CERTANILY not right so after a short pause the FIRE BREATHING DRAGON comes to life...

(Note to Author - If I don't respond it's because my ears are stilll ringing from the sound of this ROTAX thingy... YES IT IS VERY LOUD...)

BTW - I'm running custom made single exhaust on each side (by who is anyones guess) but it was all done with Mig Welding and it would have taken a lot of time (acording to my welding buddy)

ANYHOW OFF I GO....

As with any two stokes (they really don't like to idle) after a little feather'ing of the throttle we are gone...

(To the concerned LAW Enforcement People watching this list - This was done on PRIVATE PROPERTY (which I own) so don't Frett It...

Once I get the motor (( Internal Combustion Engine ? )) to Clean out I notice - THE EGT GUAGES ARE READING ABOUT THE SAME- I suppose this is a non issue to you VETERAN Twin Cylinder MASTERS - But I was pleasently suprised. (is this normal ??????)

So now its time to see what this ROTAX can do...

I'm in the middle of road and I nail it ....
Off we go... As soon as I hit it I can tell that traction is going to be a big isssue (for the record I am running about 1 psi - (YES I KNOW THAT IS A FLAT TIRE)

I try about 3-4 dead stop starts and I seem to have no trouble breaking these bad boys loose on Hard Pack...

SO next I try the same dead stop from the neightbors freshly disked field....

I NOTICE A HUGE DIFFERENCE (READ - SCARED THE CRAP OUT OF ME) one minute I'm looking across the field and the next all I see is STARS...

After a few more rums I KINDA of like THIS NOSE NORTH STUFF...

Anyhow after all is said and done I'm sure I still have a lot of carb and cluch tuning to do so if anyone wants to offer some advise I'm all ears....

Speak Loudly Please...

Right now All I hear is that ROTAX RING....
(BTW - I keep hearing an Arctic Cat EFI calling - SHOULD I LISTEN ????)

Later
Dennis (FL670R)

Glad to see you got it running how is the throttle responce?

Mag side on a twin always runs hotter than the clutch side that is why you see larger jets on that carb I have had a few sleds that someone has scratched LEFT and RIGHT on the carbs to keep them straight.... At low RPMS I would not worry about temp diff.

Traction haha I got traction problems with my Pilot, that 670 should pull 2x harder than any of your other Pilot's, are you going for more tuning this weekend?

I would love to see some pics. If it running that good already, you must be close on jetting!

Hey Dennis, have you just been working on the Engine, or on the whole machine? I'm wondering how it will handle, are working over the suspension also? It will interesting to see it when it is all done, expecially in comparison to what it looked like last time I saw it. Good Luck, Jerry

Can anyone tell me why the Mag side is always hotter ?

Currently both Carbs have the same size Main and Pilot Jets...
These are supposed to be aftermarket "High Performance" Carbs

Throttle response is good but not great - I think it'll take me a while to get them jetted correctly...

I believe I'll have to wait until spring now before I can do anymore tinkering...
Friday (Test Day was 55+ degrees) Saturday and today its 15 degrees and currently we have about 4" of the white stuff... BURRRRR...

I've olny been tinking with the Engine and Carbs... This pilot has a brand new Long Travel suspension from ATVR and Axis shocks... Based on the short test runs I was taking Friday I'd say the suspension is already very close...

I haven't done much to the basketcase that I picked up on the last LS trip.
I've just removed most of the plastic so that I could see where the frame needs some attention...
I also removed the frozen rear brake caliper so that I could play with it in the snow...

Later
Dennis