Hi there, i have a superjet 1993 650 engine which has recently been rebuilt and supposedly bored out to .5mm i believe, I have run it in with no issues after the fourth tank i noticed the seals had popped out (after a moderate ride on a calm day) and were hanging on the driveshaft, infront of the drive coupler. Any suggestions as to what may have caused this? Stu
The seal might have been installed the wrong way round on the rebuild. Would need a pic to see though.
I have seen it happen from a badly aligned engine and also from a stuffed midshaft housing which caused excessive shaft play. Did you check alignment or just throw it back together?
Normally only 2 things that cause that. 1.... Seals installed incorrectly. 2.... A decent backfire can blow them out.
the cheaper aftermarket seals are more prone to this too, as they seem more flexible.... Only use the OEM spec seal which is the 'ARS' brand made in japan, a few companies sell these , Genuine Yamaha, Pro-X ...
what alignment are you meaning? drive coupler thing? How can i prevent a back fire and what would cause it? And its now too late for changing seals as the engine rebuilders put new ones back in dammit
Post a picture. If it turns out the seals are installed incorrectly and you paid them to do it, they should really put it right. Its not a major to do just a pain especially on a newly rebuilt motor.
Make sure the out side seal has the 4 little tabs on it. If it has the 4 tab seal on the inside it will push the seals out
