these two parts work for RTR engines in a comp,
40674 and 10040
The 10040 is a large diameter flywheel for rtr engines, since the pull start hangs lower than the engine you cannot put on non pull start mounts. so look at your flywheel and measure it. Or you can look at it on a table. when you put it on the table the engine should be tilded alot because the flywheel is large, if it's close to sitting flat on the table then you have a non- pull start flywheel and need to go to the biggier dia. flywheel 10040.