Rotax Engine in EZ GO Cart

[ray-soccer]

I have installed a Rotax 660 Engine from a 2003 Ski-Doo Snowmobile in my 2001 EZ Go golf cart. The engine runs fine on low, but it chokes when the gas pedal is about half way depressed and it does not respond well. The maximum attained speed is about 12mph. I have inspected the spark plugs and they are flooded with fuel. I did not install the original air box. I have installed pod K&N air filters. This engine comes with dual carburetors. I live in southern California and this engine came from New York. The original exhaust pipe with the expansion chamber was installed, but we had to cut it and weld it to re-direct it from its original position of the snowmobile in order for it to fit in the golf cart. I have bought the repair manual for this engine and it shows that the original carburetor main jet size is 380. My question is, do I have to re-Jet the carburetors so I the engine could run the way it supposed to run? Thank you for the help.

[professorjason]

Yes i would say for sure you need smaller jets

[chardonite]

I would make sure the choke is all the way open...

[ray-soccer]

Any idea what jet size it should down size to? considering that I'm running K&N pod filters........I adjusted the pedal cable and it does open all the way up.....

[DOOmsman]

Ray, you are in uncharted water, You have Kns on it and operating in a warmer climate.
You will be jetting down and checking the plugs often till you hit that pretty tan color.
Becareful about what jets You use, Mikuni has some funky sizes. see the chart here.
http://www.snowtechmagazine.com/arti...se/dontuse.php

[EZ-GOnewild]

Will the original air box fit now? If it does then I would try running it with it on and see how it runs.

How much did you add/subtract to the original muffler?

[ray-soccer]

thanks for your imput

[ray-soccer]

I can not use the original air box because it does not fit. I have installed the original exhaust pipe with the expansion chamber, but have added a 5" in length muffler which is not enough to muffle the noise. What muffler size do you think I should add? Also, does the muffler make a difference how the engine runs? I had been told that the exhaust needed to be installed for sure because of the exansion chambers? thanks for the help.

[EZ-GOnewild]

Yes, you need to run the original muffler/expansion chamber. It is part of the tune on the engine. 2 cycle engines need the expansion chamber to pulse the exhaust gases. I would modify it the least amount you can to get it fit and then fire it up. My guess it will run like it should.

[ray-soccer]

I'm running the original exhaust pipe with its expansion chamber (one piece all together,) but without the oginal muffler. Are you suggesting that I also installed the original muffler and it should solve my problem. Thanks for the info.