I’m looking to buy a used kart with a Rotax max engine. I want to race it locally in club races, but also in official Rotax races. Therefore I obviously need a engine with all the updated required parts like the new style clutch, etc. However there are various used engines out there, some completely updated and Rotax Max legal, and some with the older parts.
I’m trying to find out how much it would cost to have a Rotax with the old style parts updated to be completely Rotax Max legal. That way I can weigh the cost of buying a updated engine upfront or buying an outdated one and then have it modified.
Also, does the number of things that need to be updated affect the cost? Or will it need to be completely rebuilt either way? I’m still very new to the technical aspects of karting so forgive me if my questions are a bit amateur.
If you have an old Rotax engine with zero upgrades. Its not worth it to upgrade in my opinion.
Old black coil change to new style green coil. $450.00
Clutch conversion kit with balance gears ect. $500
2009 or newer cylinder $600-700
New style air box around $150-175
With a new cylinder comes the need/cost of a new piston kit $150. Plus the cost of dealer/service center for labor. Clutch being a newbie done by service center. Coil and airbox you could change out.
Rebuilds are based on hours of use on engine. Rotax Top end about every 20-25 hours and bottom rebuild 40-50 hours of use.
Follow up question. If a slightly older Rotax engine was recently fully rebuilt, does that mean the clutch and older parts were updated during the rebuild? Or can it just be rebuilt but with the older parts still intact.
I’m asking because sometimes I see Rotax’s for sale that were recently rebuilt, and I usually assume that they have all the updated parts due to that. But I’m not sure because I don’t know what a full rebuild even entails in terms of parts being worked on.
Rebuilding an engine and upgrading the clutch are two separate items. The engine can be rebuilt using the old clutch, drum and gears. Visually you tell the old from the new clutch and drum by the clutch drum. The older drum will have holes in the front face, the newer ones don’t. The gears should be replaced when the new clutch is installed, but the only way to know is to pull the side cover of the engine. Below is the old style clutch.