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That's an example of valve lash adjusted way too tight, resulting in hammered adjuster and valve tip. A little while back I came upon the same thing, I posted some pics in this thread:
http://www.xs650.com/forum/showthread.php?t=28536
http://www.xs650.com/forum/showthread.php?t=28536
Brian902
XS650 Junkie
Wally,
I would think it would be very difficult to determine which failed first, but would be suspicious of the adjuster.
Valves were probably replaced new at some time and the adjusters were not.
I used new ones that I believe are from a Volkswagen. They have a 5mm allen head and are much nicer to work with than the original square head.
Sorry about the bad pics. Camera working poorly.
(operator error more than likely)
I would think it would be very difficult to determine which failed first, but would be suspicious of the adjuster.
Valves were probably replaced new at some time and the adjusters were not.
I used new ones that I believe are from a Volkswagen. They have a 5mm allen head and are much nicer to work with than the original square head.
Sorry about the bad pics. Camera working poorly.
(operator error more than likely)Attachments
That's sort of a normal occurrence over time. The Yamaha design is piss-poor. The tip of the adjuster screw is rounded off so only one tiny part of it contacts the valve stem. Eventually, this wears out the tip of the screw and dimples the top of the stem. You can replace the screws but eventually the new ones will do the same thing. That's why we switch to the VW elephants foot adjuster screws. They cover the entire top of the valve stem so this doesn't happen.
What is the curvature of the elephoot? There's a lot of the standard adjuster face that never touches the valve. I'm thinking if there's a value to the elefoot it must be that it helps guide oil to the valve stem top.
In my opinion, that's an example of valve lash adjusted way too tight, resulting in hammered adjuster and valve tip. A little while back I came upon the same thing, I posted some pics in this thread:
http://www.xs650.com/forum/showthread.php?t=28536
http://www.xs650.com/forum/showthread.php?t=28536
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Yes, the stock adjuster hits the valve tip slightly off center, causing the valve to rotate. This is mentioned in the thread I cited previously, I mention its effect on my own hammered valve tip, causing it to go in and out of adjustment. I do not know if the elephant adjusters rotate the valves.
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have you got a part number or VW model or link by any chance of the large head adjusters?
I cannot find a 4mm sq spanner anywhere and 4mm is way too small to work with anyway.
These are on a UK site http://www.coolairvw.co.uk/Item/Sho..._8mm_Elephant_Foot_Style_Valve_Adjusters.html but you have to buy eight. Seriously, I'd split 'em with you but my engine isn't coming apart any time soon. You going to that JapFest thing next week? Someone there might split a set with you.
ouch !.
......gimme my arm back lol
Cheers Dave , I guess I can live with them afterall
Yep I'm hoping to make the Japfest. I just booked the bike in for an MOT next Weds and I haven't even got the engine in yet !
No pressure there then
......gimme my arm back lol Cheers Dave , I guess I can live with them afterall
Yep I'm hoping to make the Japfest. I just booked the bike in for an MOT next Weds and I haven't even got the engine in yet !
No pressure there then
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The CB Performance screws in that link are the better (and more expensive) ones. EMPI makes a cheaper set, about $30 for a set of 8 here in the states. I do the same usually, split the set with someone. Then, at about $15 for 4, they're not much, if any, more than stock type replacements.
http://www.dansperformanceparts.com/buggy/epc/buggyep 6 rockers.htm
Even though the EMPI screws seem to be working fine for me, I may spring for the supposedly better quality Bugpack ones next time. At about $5 more for 4, I don't think that's too much for these.
http://www.dansperformanceparts.com/buggy/epc/buggyep 6 rockers.htm
Even though the EMPI screws seem to be working fine for me, I may spring for the supposedly better quality Bugpack ones next time. At about $5 more for 4, I don't think that's too much for these.
DaveO's link shows the CB adjusters, the only ones I've found to have full-length threads.
You can look in my album 'elephant foot adjusters' for close-up pics...
You can look in my album 'elephant foot adjusters' for close-up pics...
xjwmx, the Porsche elephant foot adjuster are flat where they contact the valve stem. The center of the foot hits just off center like the stock adjuster does and it may not turn the valve as much but I think it still turns the valve.
It looks like the flat foot on a C-clamp. The flat foot has a ball and socket connection with the adjuster screw. This ball and socket fill with oil and this dampens the noise a bit.
The flat surface of the adjuster and the flat surface of the stem makes getting precise clearances easier.
The increase in surface area where the flat on the adjuster contacts the stem decreases the wear dramatically. The ball and socket has a much larger contact surface than the stock adjuster to stem, so the wear on the adjuster is decreased dramatically. This decrease in wear means you have to adjust much less often.
So more precise adjustments done much less often sounds like a win win situation.
To use them you need to mod the rocker arm a bit. This may weaken the rocker arm a bit but I think it was way over built to start with.
Leo
It looks like the flat foot on a C-clamp. The flat foot has a ball and socket connection with the adjuster screw. This ball and socket fill with oil and this dampens the noise a bit.
The flat surface of the adjuster and the flat surface of the stem makes getting precise clearances easier.
The increase in surface area where the flat on the adjuster contacts the stem decreases the wear dramatically. The ball and socket has a much larger contact surface than the stock adjuster to stem, so the wear on the adjuster is decreased dramatically. This decrease in wear means you have to adjust much less often.
So more precise adjustments done much less often sounds like a win win situation.
To use them you need to mod the rocker arm a bit. This may weaken the rocker arm a bit but I think it was way over built to start with.
Leo
^All the pics I've seen had them laid out straight so I didn't know the pivot was there until the link above.
I've replaced several tappets using vw bug tappets, some at least twice. My valve ends seem fine though. If I was replacing the valves and couldn't be sure of their quality I'd sure consider elephant foots though.
I've replaced several tappets using vw bug tappets, some at least twice. My valve ends seem fine though. If I was replacing the valves and couldn't be sure of their quality I'd sure consider elephant foots though.
sailor
XS650 Enthusiast
Does the length of the VW/Porsche elephant foot adjuster need to be modified to fit height wise above the rocker arm?
