You don't say what engine you have, however, on the pull start engines i sell you have to change the backplate if you want to run without the pull start. Engine then becomes a bump start. I also have roto start conversion kits for the STS 28 monster engine that will probably work with any 28 engine. I'm not sure but the local hobby shop has been buying from me and they don't carry the STS engines so i guess it works. If interested drop me an email at [email protected]. Visit my site www.projectzen.net