I have 2 Saito 150 and haven't had any real problems with either. One was an earlier version mentioned above and I "tamed" its handling by installing a decompression shime made by C&H Electronics. It takes about 30 mins do instal and has really improved its running characteristics. Since I had an extra shim lying around, I installed it in my newer 150 and will test fly it next weekend to see if it smooths-out the newer series engine also.