MRP Motorsport Community
MRP Home Birel America Go Rotax KartingBiz Register FAQ Members List Social Groups Calendar Search Today's Posts Mark Forums Read

Go Back   MRP Motorsport Community > Technical Support Forums & Discussion > Rotax Max powered by ShopMRPOnline.com

Reply
 
Thread Tools Display Modes
Old 05-23-2010, 11:38 AM   #1
Edward louis
Rookie
 
Join Date: Oct 2009
Posts: 11
Default micro rpm's

had a race last weekend where a competitor was turning atleast 300-400 more rpm in a FIXED gear class. My pro tuner nor tech guy could not figure it out(they all heard it and thought the guy was cheating) We where on the fence regarding a advantage because we crossed the finish side by side and set track record but could not figure out how they where doing it?

We checked tire sizes.

any other thoughts?
should the crank case have a breather tube on it?

thank you

Birel/micro racer!

Last edited by Edward louis; 05-23-2010 at 11:38 AM.
Edward louis is offline   Reply With Quote
Old 05-24-2010, 07:59 AM   #2
Clay Maddox
Rookie
 
Join Date: Jan 2008
Posts: 31
Default

It could be because of the cylinder. Minor differences in port heights could provide alittle more RPM.

Were you and the competitor running 09 cylinders or one running 09 & other not?

For the crankcase breather tube, I assume you're referring to the left side gear box area. There is a spot to run a tube on the left front fill cap but most people do not run a tube. I think from the factory the Rotax comes with a yellow cap fitted to the gearbox vent. I put a short piece of fuel line on the vent and then screwed a M6 bolt into the fuel line to seal it off.
Clay Maddox is offline   Reply With Quote
Old 05-24-2010, 09:55 AM   #3
Edward louis
Rookie
 
Join Date: Oct 2009
Posts: 11
Default

We both had 09 cylinders.


thanks for the response.
Edward louis is offline   Reply With Quote
Old 05-26-2010, 01:58 PM   #4
Andy Seesemann
Birel & Rotax Specialist
 
Join Date: Jan 2008
Posts: 104
Default

As of this morning, this is no longer legal.

Per Don Moormeister.

EFFECTIVE IMMEDIATELY
CLARIFICATION
SIDE COVER BREATHER MUST BE FUNCTIONAL
Any effort to change “Breather” function will be a post race technical inspection item.
Violation will result in disqualification from competitive element involved.
To be clear, this prohibits folded hose on breather.


Don Moormeister
National Tech Director
United States Rotax Max Challenge


Andy
__________________
Andy Seesemann
Full Throttle Karting
www.fullthrottlekarting.com
GATORZ Karting Cup
www.gatorzkarting.com
Andy Seesemann is offline   Reply With Quote
Old 05-26-2010, 03:09 PM   #5
pskjerven
Rookie
 
Join Date: Nov 2008
Location: San Jose, CA
Posts: 29
Default

Edward - could be a number of factors effecting RPM difference but I would think it is more than likely in carburator settings - jetting, float bowl height, clip position.

It could be that you had slightly better low rpm off the corner, but he had slightly better high rpm at end of striaghts - thus the reason for still coming across the finish line the same. Caveat - I am no expert, still learning myself.

At Infineon raceway this last weekend (Northern California - sea level) our Micro was turning between 9800 and 10,000 as a high RPM one day.

What kind of RPM's were you seeing and what were the weather conditions?

Paul
pskjerven is offline   Reply With Quote
Old 05-26-2010, 11:04 PM   #6
Edward louis
Rookie
 
Join Date: Oct 2009
Posts: 11
Default

sorry i was running 2 classes that weekend w 1 micron, i chose the other class to keep micron on.

weather was 75 ish in final and bad air real humid. 100 ft above sea.

Last edited by Edward louis; 06-11-2010 at 11:01 AM.
Edward louis is offline   Reply With Quote
Old 06-02-2010, 10:38 AM   #7
Edward louis
Rookie
 
Join Date: Oct 2009
Posts: 11
Default

well i wanted to update everyone on my original question. My Tuner ran into my competitor at a regional race where my competitor was still out revving everyone so he kindly told tech they better start checking gearing. At the race i was in against him they did not check, I even assumed know one would be crazy enough to run a wrong gear in a spec class.(and i bet thats what they where hoping for) BUT BAM! what do you know he was running the wrong sprocket in the front DQ!

I guess that got solved

Last edited by Edward louis; 10-17-2010 at 04:47 PM.
Edward louis is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 01:21 AM.

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright 2008 - MRP Motorsport - All rights reserved