HarleyTechTalk

Technical Forums => EVO 1340 => Topic started by: 86fxwg on November 10, 2022, 07:37:46 AM

Title: S&S Valve timing issue?
Post by: 86fxwg on November 10, 2022, 07:37:46 AM
Full story as clear as i can make it.
Bike is a 90 fxr w/S&S engine. Not sure of the size,but not relavent.
Out riding hard, bike just qiute,died,no noise.
Got trailer halled it home,pulled plugs,NO Compression,Leak down showed no valve leakage.
Pulled cam cover, Thought Cam gear might have slipped,Its lined up with marks on key way,looks good!
Dahm,What the hell!
Pull Cam gear off crank, stepped keys way gear sheared on drive gear side.
Oil pump turns (pumps oil just turning by fingers), breather gear turns SMOOTH!
Install new gear key, line up cam dots with Breather & cam gear & crank gear dot.
Now for the ?,
With dots all lined up,shouldnt rear piston be @ top dead center?
Both pistons are down,@ least half way! WTF?

86
Title: Re: S&S Valve timing issue?
Post by: xlfan on November 10, 2022, 07:51:13 AM
No, that lineup is for those gears only.
 
Title: Re: S&S Valve timing issue?
Post by: 86fxwg on November 10, 2022, 10:43:20 AM
So just because dots line up does not indicate TDC on an evo! Alway thought it did!
Twinn Cam,Small block chevy,Ford,Dodge all indicate tdc on # 1 or #6 cyl.
Day wasnt a waiste,Learned something.
Thanks
86
Title: Re: S&S Valve timing issue?
Post by: xlfan on November 10, 2022, 11:37:20 AM
Look for the TDC mark for no. 1 cyl. in the left side flywheel window when front cyl. tappets are in low position.
It doesn't make sense to use cam compartment gear markings for anything but gear assembly, because you can't disassemble cam cover without releaving valve spring tension.