I just finished putting my '96 formula III motor into a '97 formula III chassis.

Should I use the carbs that came with the '96 or should I use the '97 carbs? *They are both VM-36 Mikunis but the '97 uses straight jetting (176 mains) while the '96 uses staggered (172-173-172).

It is idling very high. *After running it will go down to about 2600, then climb to 3100rpm. *I didn't alter any of the settings so I don't understand why it has the high idle but why might the idle be climbing if it sits for a few seconds?

It's smoking a lot. *I'm not sure what oil is in the bottle but it is smoking more than what a oil that is known for smoking would produce. *The oil pump is set with th lines aligned with the throttle closed.

When I use the brake it makes an initial clunk sound/feeling but stops fine. *What causes this?

I haven't looked into any of these issues yet as I'm exhausted from working on it all day. *If anybody in the Northern IL area wants to come by and assist in the tuning, don't hesistate to PM me *http://www.snowmobileworld-s2.com/forums/iB_html/non-cgi/emoticons/smile.gif

Use the carbs that match the motor. 96? Your idle could be the cable being to tight. Any play at the throttle? Chain could be loose causing the clunking noise. Good luck.

Also are they both triple pipe motors? Could be different pilots as well.

Yes, both are triple/triple engines. *I'll check for slack in the cable. *When I moved the carbs from one sled to the other I didn't remove the cable though, so no settings could have been changed. *They do have slightly different throttle levers so I will look into that.

Jetrep
Ihad a 96 and a buddy had a 97 they were both jetted the same from factory 330 -350-330 soiwould say you are lean unless you ride at 10000 ft. we are at 2500 and jet 280's all across. greygoat

My mistake, reading Ronnie's I thought that the number following the carb type/size was the main jet size. *The '96 came jetted 330-320-330 like you said while the '97 was 330 for all three. *If they revised to the straight for '97 would it be a good idea for me to do the same?

I wouldn't be too concerned about 10 points