what was he doing?

Randy Dye · Posted: Wed Jul 18, 2001 3:35 am Post subject: what was he doing?

I recently watched a Rotax Max race and saw one driver "messing" with the carb. as he drove. He would reach over and tune(?) as he came out of a corner. After looking at a Max carb. there appears to be a primer lever. It is the only thing this driver could have been using as he ran. Was he using the primer to dump fuel into the carb. and cool the motor or gain performance?

Pete Van Ginkel · Posted: Wed Jul 18, 2001 3:45 am Post subject: what was he doing?

I thought that lever was just a choke.
Pete

Glenn Holland · Posted: Wed Jul 18, 2001 7:49 am Post subject: what was he doing?

There've been a few times I have wished there was something I could mess with on that carb while I was driving. What would the effect be messing with the choke while running?

Glenn

Marc Miller · Advertiser Joined: 18 Jul 2001 Posts: 1834

If you;ve ever seen a formula A, or other direct drive races, you will see the drivers placing their hands over the carb or air box holes to "choke" the motor for better acceleration, dumping fuel out...

I am guessing he was utilizing this technique.

MM

Stephen Buckley · Joined: 18 Jul 2001 Posts: 861

I can find no rule in the Rotax technical specifications that refers to a spec airbox placement. The lever in question is the choke. The low rpm circuit is entirely controlled by the idle jet, which really shouldn't come into effect in a race unless there is a very tight hairpin turn. I would have to assume that:
A) The driver was choking the air intake ducts, or
B) Avoiding a possible airleak by supporting the airbox/carb/bracket assembly.

I am not positive that the "choking" effect has any real value because the carb is a fixed jet type. Maybe the driver was a little lean (popping) and he was taking precautions.

bird · Joined: 17 Jul 2001 Posts: 147

I think they are catching people under the "no modifications from standard" (or whatever it is) rule regarding the engine and it's anciliaries. Another thing someone got nicked for last week was putting tape over his powervalve to stop other competitors from copying his setting. These strict rule interpretations lead me to start planning to protest people for having pod stickers or similar...

Pete Van Ginkel · Posted: Wed Jul 18, 2001 12:21 pm Post subject: what was he doing?

Im going to have a liitle decal made that looks like the powervalve dial. I`m going to stick it on the opposite of the real setting.

Sneaky Pete

Glenn Holland · Posted: Wed Jul 18, 2001 1:32 pm Post subject: what was he doing?

quote:
Originally posted by Stephen Buckley:
B) Avoiding a possible airleak by supporting the airbox/carb/bracket assembly.

That's possible, as I had my airbox come loose at my last race (road race). Once it came loose, I lost 3 seconds per lap.

I think I'll be driving around holding it from now on.

G.

Glenn Holland · Posted: Wed Jul 18, 2001 1:33 pm Post subject: what was he doing?

By the way, we should probably move the Rotax discussion into 2-cycle, don't you think?

Glenn Holland · Posted: Wed Jul 18, 2001 10:06 pm Post subject: what was he doing?

The air intake on the airbox for a Rotax is underneath the box and cannot be reached. Maybe he thought he was doing that...

bird · Joined: 17 Jul 2001 Posts: 147

are you guys allowed to rotate your airboxes? people keep getting busted fot it here

- Mary-Ann www.kartlink.net

Rob Hogenmiller · Joined: 20 Jul 2001 Posts: 855

Funny you mentioned that Mary-Ann I was just looking at that the other day telling my buddy WOW we can get some forced air here. Any how I figured it would be illegal so we didn't do it.

As for flipping the choke. I seem to recall that it is illegal to do that. Something about when kart is in motion. I'll try to find the exact rule so you can verify that.

John Neilson · Posted: Fri Jul 20, 2001 5:41 am Post subject: what was he doing?

Glenn, Pete, This is an OLD trick we used to run on Enduro bikes. When the course would take you through extreme elevation changes we would mount a cheap lawnmower throttle lever on the bars and jet the carb lean. The lever was attached to the choke and as you needed to richen the mixture, you just fed a little fuel from the choke. Man , that takes ME back some years!!

Pete Van Ginkel · Posted: Fri Jul 20, 2001 7:18 am Post subject: what was he doing?

Hey Randy,
Next time you see the guy doing this why don`t you put on a yellow windbreaker and yell to him, "What are YOU doing?"

Pete

Chaz Clover · Joined: 18 Jul 2001 Posts: 879

I don't remember seeing anything in the IKF rules regarding position.

Chaz Clover
http://www.kartmonster.com

quote:
Originally posted by Mary-Ann Horley:
are you guys allowed to rotate your airboxes? people keep getting busted fot it here

- Mary-Ann www.kartlink.net