How to add weight to Rotax

Rick Blood · Posted: Tue Sep 18, 2001 11:32 am Post subject: How to add weight to Rotax

If your local kart shop doesn't have any lead then you can use divers weights mounted on the seat preferably. Scaling the kart will determine the proper location.

You may want to go in and edit your log in name before Glenn scolds you.

Michael Taksa · Posted: Tue Sep 18, 2001 1:52 pm Post subject: How to add weight to Rotax

I used lead. Bought at a scrap yard at 20 pennies/lb. Dive shop Wanted $2/lb....
Molded it right into a baking or cooking pan, mount to seat. You want to put you kart on scales to determine better position. Use 5/16" minimum dia bolts and counter - nut them.

areddy · Joined: 18 Sep 2001 Posts: 4

I am under by 30LBs on Rotax 125, any thoughts on how to add weight? What to use where to add???

Jeff Edwards · Joined: 10 Sep 2001 Posts: 193

Anil,

If you handle lead, be sure to use gloves, because to avoid getting the lead on your skin. I suggest that you try the plumbing supply or some roofing supply for lead 'ingots' which they use for soldering pots. They come in five pound pucks which you can then drill a hole through the center for the bolt. I painted mine to make the handling of them safer. If you do melt down your own, do it outside and use a facemask specifically made for lead, not just a dust mask.

Don't forget to use safety wire on all weights. Check them after each race day or incident, as lead reshapes itself and will become loose.

Congratulations on choosing the Rotax Max. I'm very happy with mine.

Jeff Edwards

John Denman · Posted: Mon Sep 24, 2001 4:49 am Post subject: How to add weight to Rotax

Kart balance and avoid changes to chassis stiffness are key points. Seats are the most common place to add weight. Be sure to put a fender washer under the bolt heads to distribute the stress on the seat.

Front-back weight ratios are generally 40/60 to 44/56. Seat backs, seat side are OK places to mount, just be sure the weight doesn't interfere with anything on the chassis with maybe 1/4" minimum clearance of tubes.

The height is important. The taller it is the higher the center of gravity. If you have too much bite at say 54" rear axle width, move the weights down. Not enough bite at 53", move the weights up. There are other factors for bite, such as bar settings, so this is just a relative tuning factor.

Some people pull off the endcaps on the frame rails and pour in lead shot. Very effective in soliciting others to help lift the kart on the stand........

areddy · Joined: 18 Sep 2001 Posts: 4

Thanx everyone,

I will give it a shot in the next few days and report back how well it works.