Hi I always seem to have problems with them i had a good one till the servo came loose engine went full power coupling destroyed itself

changed my prop shaft to 5mm so i could use a steel one i had

1st run went fantastic till i got a bit too close to the bank gave it a sharp turn boat jumped out the water it over throttled the coupling came loose again put it back together last night filled it with slow setting epoxy hopefully the grub screw not come loose going to try it again today it go,s again going to try a spot weld that hold it lol

has anyone else had problems with coupling if so how did you cure it

im running a jet stream 800 i changed it from ep to nitro using a force 21 engine

sorry i dont have a fix for your problem but i was wondering what water jacket did you use on the force motor

Unless you file a flat or better yet put a drill point indent into the shaft where the set screw (grub screw) seats you will continue to have problems. Since you have epoxied the coupler onto the shaft I would strongly suggest that you heat the couple, pull it off the shaft and do the suggested mod to the shaft. Use blue lock tite on the set screw when you reassemble it.

Hi John i got a good run today one and a half fuel tanks till the coupling gave up again just going to put a weld on it that do it lol water is great just now in scotland at night its freezing so no weeds in the pond and no swans too so its great fun apart from being freeing thank you for your e mail

hi i have a force 21 marine engine if you want to water cool an engine then get copper pipe wrap it around the head and use potting compound that you use for electronics that will keep it cool

i have a force .26 that i would like to make marine thats why i was asking where you got it . i didnt thank force made a marine motor

Hi if you look about you will find one with a water cooled head or try the copper pipe way that works if i see any on e bay i give you a shout

thanks . ill be looking to .