I suspect that the reason for the shims is to compensate for the increased length of the adjuster - nothing to do with the geometery. Tony
I think, but Im not 100% certain, that the shims fit under the towers that mount the rocker arm shafts on VW's in order to alter the rocker arm shaft height, and thus, the geometry of the valve actuation. I'm really anxious to see how it goes with yours and mashermoto's modification... Dan
Post by tony101bikes on Apr 17, 2007 14:06:36 GMT -5
Got my adjusters through today. On a dry run with a Shell #1 cam, I managed to get stock clearances without grinding the rockers at all! The slotted and seems to clear the covers without shortening. I think that I'll take a polish off the bottom face of the rocker with a flap wheel in the angle grinder just to make sure.
Great news about possibly not needing to trim the rockers! Which adjusters did you finally end up going with? Zim's, CB Performance, Berg? Are they the slotted or socket-type adjusters. Posts some pictures, if you can.
Post by tony101bikes on Apr 18, 2007 12:10:34 GMT -5
Sorry but I pulled it apart again and sent the cover for blasting. This is one of the inlet rockers which I set to the right clearance and then removed without touching the setting. This rocker has not been ground away at all. I would suggest taking 1mm or so off them just to make sure there's enough scope for adjustment in the future.
Hope the picture comes out ok. Is there any difference in early / later rocker type dimensions?
After giving this some thought, I don't think we would need as much grinding as we thought .....
It seems to me that only the lower front part of the rocker would need some grinding. The "foot" would pivot in the direction of the arrow when the rocker rotated down, right? This way, we wouldn't need to grind into that stiffening rib at the lower rear.
Post by tony101bikes on Apr 18, 2007 14:00:59 GMT -5
Funnily enough, I've just been out and done one as suggested. I'm just not as good with IT ............. Not bad with an angle grinder though! I've now shortened by 1/8th of and inch and recut the slot with a Dremel. The ones I got are Empi parts from Anaheim.
Post by tomterrific on Apr 26, 2007 11:20:15 GMT -5
I looked at the 5-twins pic above and verified what I thought might be the way to grind/modify the rocker tip. The elephant foot has sort of a truncated cone shape so really all that is needed for more clearance is to use a large drill bit or ball stone to relieve the area around the elephant foot on the rocker. This leaves the original strength of the rocker but grinding a tip straight off doesn't really weaken the rocker much.
The depressed Allen hex type adjusters are lighter than the slotted type due to the hole. The screwdriver type are lighter than the stock square tip type.
The elephants foot can be thought of as a bucket with a rotating ball in it. Always pre oil these before installing them. The foot fills like a bucket in operation and not only lubes the ball but cushions the valve action ever so slightly. I wish I could find these for my Triumph.
I like that large drill bit idea, Tom. I think I'll do that plus grind a little off the front. What concerns me is not being able to back that elephants foot adjuster out enough during assembly/disassembly of the head so it won't contact the cam. One cylinder is always fine at TDC because both rockers are loose, but the other one is part way through the exhaust (intake?) stroke and one valve is partly open. When I disassembled mine, I was able to loosen all 4 stock adjusters way up so none were contacting the cam. I'm not saying it can't be done but I just think it would be a bitch trying to bolt the top cover on while one of the rockers was trying to force a valve open.
Tony, you got the Porsche adjusters, right? How long are they? I ordered the allen VW ones from PJ's link. I'll report on length and mods needed when I get them.
r80rt: :)This is a splendid write up, THANK YOU!!!!
Dec 26, 2015 16:54:05 GMT -5
mashermoto: What the what is this shoutbox for? Or should I shout, WHAT THE WHAT IS THIS SHOUTBOX FOR!
May 12, 2016 22:22:21 GMT -5
motormike: Good Day ...just a FYI.. Wild Cat is this Labor Day weekend. Still go'n on. A few 650's still make the scene. Various rides at different skill levels each day.. awards dinner sunday eve. BS in the park'n lot after dinner.
Aug 23, 2016 7:57:01 GMT -5
lsettle: First post in over 6 years!
Aug 28, 2016 19:45:17 GMT -5
kardon: Wow quiet here, where did they all go.
Oct 7, 2016 2:18:13 GMT -5
gggGary: XS650.com LOL
Feb 16, 2017 20:49:02 GMT -5
buell88: Anybody have any idea who built the xs650 tracker used in the Draggin Jeans Ad on Pipeburn?
May 16, 2017 16:24:09 GMT -5
joshua: The regulator/rectifier unit I got from Mikes PMA has closer hole spacing than original. Are we supposed to mill the holes to fit?
Jun 7, 2017 19:25:58 GMT -5
joshua: My bad. I found the bracket they supplied to mount the rectifier/regulator... Uh oh. How is this meant to work? Which way is it meant to mount? Looks like I have to use some spacers or something. Good instructions would be nice.
Jun 7, 2017 22:09:52 GMT -5
craig8johnson: Not sure if this is the right spot or not but oh well...
Jul 11, 2017 18:04:15 GMT -5
craig8johnson: I'm checking the charging system. I'm afraid I might have fried the last battery. With the solid state regulator (after market) what should it be charging at. The book says, I think, 15 volts. I'm hitting 17 when revved. Is that too high?
Jul 11, 2017 18:06:19 GMT -5
gggGary: Yes 17 volts is too high, about 14 volts is max, sounds like you don't have the right regulator or it's wired wrong.
Jul 13, 2017 6:54:33 GMT -5
dean: Just saying Hello, new member who is going to fix up a 79 XS650 that has seen its better days. I will definitely have lots of questions coming up.
Jun 23, 2018 16:45:32 GMT -5
tt650: Trying to breathe life into a 1980 that's been stored (indoors) for 25 yrs. Air filters are dry rotted. Have cleaned carbs but she only runs briefly on choke then stops. Need jet setting info and other ideas that might help her idle and rev.
Jul 3, 2018 19:15:19 GMT -5
trix13: Hey everyone! New to the forum and am fighting those gremlins!! New charging system, ignition switch, coil and fuse box. Resistance is higher than normal on the ignition pick up so I'm trying to find one. No such luck yet.
Aug 16, 2018 8:50:48 GMT -5
trix13: Also, even though all of my connections are clean, I cannot seem to find out why , when at higher rpms, I hit the signals and the rpms pulse with the signals...hahah. same with the brake light. I appreciate all input!!
Aug 16, 2018 8:55:08 GMT -5
bob99: how do I post a question. I am new to the forum
Jun 6, 2019 10:52:10 GMT -5
adlpc: Hello all! Been enjoying your edifying posts and discussions - and as a fan of the XS650 since my early teenage years happy that I now own a 1980 Special which I plan to turn into a vintage half faired racer. Thank you all for being here!
Oct 1, 2019 0:58:56 GMT -5
jimothyj: Hello everyone, I just joined & wish would have known about this site in 2014 when I brought my 1974 TX650A back from the grave. I have spent a good deal of $$ and alot of time on it. Just painted it and working on electrical, I will post pics soon,
Apr 10, 2021 2:14:13 GMT -5
louisvan: trix13 - I had a problem with my 1975 SX650. When I got to highway speeds, the engine lost power. The problem was in the connectors. At a certain vibration and the wind pushing on the wiring loom, the connector lost continuity. A bad crimp to the wire.
May 20, 2021 1:19:09 GMT -5