snopro
New member
i am installing a new crank in my bottom end.
the pto side crank seal is rubber on one side and metal on the other side. it seems to fit in the case ok with the seal set each way.
is the metel side of the pto crank seal suposed to go toward the inside of the case or does the metal side of the pto seal go toward the outside of the case?
the pto side crank seal is rubber on one side and metal on the other side. it seems to fit in the case ok with the seal set each way.
is the metel side of the pto crank seal suposed to go toward the inside of the case or does the metal side of the pto seal go toward the outside of the case?
YAMMIEGOD3:16
Active member
SNOPRO, THIS IS INTRESTING. I ALWAYS USED YAMAHA NOS CRANK SEALS ON MY SRX MOTOR,S AND ALWAYS PUT METAL OUT. NEVER HAD ANY ISSUES. ALSO HUGE TIP HERE. BEFORE YOU REASSEMBLE THIS, GET YOURSELF SOME RED LOCKTITE AND ADD A DROP TOO EACH DOLL PIN ON CRANK SHAFT. THIS WILL HELP SUPPORT ALL BEARING IN CASE AND PREVENT BEARING FROM EGG SHAPEING SET HOLES AND CAUSEING BEARING TO '' CHUCK '' AT HIGH RPM. I MIGHT HAVE YAMAHA YECH BULLETIN ON THIS. 3:16 (tony)
snopro
New member
yeah. that makes sence. metal out to protect the seal from belt debris. i just wanted another opinion. strage how the seal fits good placed both ways, you'd think yamaha would have made it so the the pto seal goes on one way only, like the mag side crank seal does. my dowel pins are in pefect shape and bearings are of course all new but the loctite idea still sounds good even though with everything put together correctly, there shouldn't be any chucking going on.
YAMMIEGOD3:16
Active member
I HEARD ABOUT THAT LOCTITE IDEA YEARS AGO AND SAID, '' NO WAY ''. BUT THAN LIKE I SAID I THINK I REMEBER A TECH BULLETIN RIGHT FROM YAMAHA ON THIS. MUST OF BEEN A PROBLEM, SO I DID IT AND NEVER HAD A PROBLEM. YOU INE WITH YOUR SEAL !! 3:16 (tony)
I allways thougt that the metal side of the seal should face out but then I got a bit puzzled when I got me a another 77 srx bottom end that appears like it never was opened and it had the rubber side out. I then looked for pictures of the seal i varios srx manuals, and heureka there it was, a picture of the pto side showing that the seal indeed goes with the rubber out. No big deal but there it is.
Picture from the manual.
Picture from the manual.
Last edited:
YAMMIEGOD3:16
Active member
TO TELL YOU GUYS THE TRUTH, THATS THE WAY I THOUGHT THAT SEAL WENT. JUST LIKE THE MANUAL SHOWS. BUT OVER THE YEARS, I SEEN SEVERAL THE OTHER WAY. MATTER OF FACT REMEBER DISPUTEING THIS WITH AFEW GUYS AT RACES. WILL I DID IT THEIR WAY MYSELF OVER THE YEARS AND NEVER HAD A PROBLEM. TELL YA THE TRUETH, YOU BE OK EITHER WAY, BUT I WOULD PROBLEY DO IT THE WAY BOOK SHOWS. 3:16 (tony)
Agree I allways put the metal side out myself, never a problem. Never thought about it really, untill I got this other bottom end and saw this tread. Oh well...
Wouldn't The Gas Effect The Rubber Over Time If It Was Facing In?
I Also Have A Brand New Crank Still In The Box And They Came With The Seals And The Seal Is Packed With The Rubber Facing Out. I Just Opened It And Looked
YAMMIEGOD3:16
Active member
ANY DOUBT, JUST FOLLOW MANUAL. 3:16 (tony)