i have a 1978 evinrude 140. when the engine is cold its very hard to start. once warm it starts easily. when i go out i can only get it up to about 3000 rpms. if push the choke in for a sec at the 3000 rpms it picks up about 200 more rpm's but then goes back to 3000. i've rebuilt the carbs, checked the coils, tested spark at idle and all cylinders are fireing. the compression on all cylinders is between 125 and 130. any ideas as to why i cant get wot?