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Post by mattb on Dec 12, 2007 0:00:36 GMT -5
On this forum and others I've read people refer to the oil line as feeding the "inlet" rocker, whereas I'm sure from its position that mine feeds the exhaust, and indeed Vanem's sales pitch for their dual line states that "The original Yamaha oil line supplies oil only to the exhaust side of the cylinder head." Is this a difference of earlier and later models, a common typo, or what?
Cheers,
Matt
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Post by fenz on Dec 12, 2007 1:41:24 GMT -5
Standard on the early models SR XT TT was to oil the inlet valve only.All after market kits oil either both or just exhaust valve which is the hottest of the two valves.
I think they rectified this on the latter models that have been imported from japan(oil to exhaust valve)
Common to see the exhaust valve rocker arm pad to be chewed out due to lack of oil on the hot valve side.
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Post by bigshingle on Dec 12, 2007 9:51:23 GMT -5
Like most SRs I've seen, mine came with the oil line running to the intake side.
Following the advice posted awhile back, I've added a dual line — one going to both inlet and exhaust.
From talking to people who've done that (that would be you, Miker) I understand it quiets down the top end rattle somewhat.
I'm guessing everyone here will agree adding the second line is one of the best things you can do for your bike.
I ordered mine from Thumperstuff, but in an October 2006 post Fenz showed how to make one. Have a look at that.
No matter what, I'd do it somehow.
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Post by miker on Dec 12, 2007 12:11:11 GMT -5
Yes, this would seem to be one of the "must do" mods for the SR. I knew mine was working because the top end was instantly a bit quieter than before. I used the Thumperstuff kit which adds an exhaust rocker line to the stock intake rocker line. It was easy to install but includes threaded aluminum parts, so be careful not to strip them!
miker
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Post by wotavidone on Dec 12, 2007 17:57:55 GMT -5
Gents,
The purse strings have been tightened at my house somewhat. I would dearly love to do the oil line thing to both my XT and SR.
It looks like I'll be doing it myself if I want it done.
So, I'm hoping I can get some advice:
The plug on the left hand side of the head at the end of the exhaust rocker shaft is where the oil is to be directed? No springs or shims controlling end float, or seals around the shaft controlling oil flow?
What's behind the plug, is it just a case of drilling and tapping that plug to take an oil line fitting?
Would a tee-piece in the original oil line with a line around to the exhaust do the job?
I can probably lay my hands on some swagelok fittings, tubing, bender and a cutter to do this with, and make a nice neat job of it.
I guess I'm attracted mostly because I keep hearing that the top-end noise is instantly reduced. Shallow reason, I know, but I love the idea of the exhaust thump being the only noise I hear.
What you guys reckon?
Mick
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Post by colinjay on Dec 12, 2007 18:50:33 GMT -5
Mick,
I say give it a go.
Most of the oil line kits supply a new "bolt" with a 8mm thread tapped into it to replace the existing chromed blanking "bolt". These are made to replicate the inner dimensions of the original "bolt", there are no shims etc in any of my 500 engines, so I don't think that it is ultra critical. I heve thought of making my own oil lines in a similar manner to what you suggest.
CJ
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Post by frankyb on Dec 12, 2007 20:54:49 GMT -5
Hi Mick, take the plug bolt out of the end of the rocker spindle, weld it in where its dished, and drill and tap for a banjo bolt. Any bike wreckers should have heaps of banjo bolts and fittings. Make your lines up to suit, the cheapest and easiest way being get an old banjo fitting, cut and flare the metal line and clamp hosepipe on it. These are not high pressure lines, just increased volume. Cheers Franky b.
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Post by StewRoss on Dec 13, 2007 1:35:54 GMT -5
Hi, You can go to a hyd fittings place and get the threaded banjo fittings and have a line made up with the screw on fittings at each end...braided stainless looks good. I got a banjo bolt to suit the fitting and drilled and tapped the standard bolt...From memory I may also have machined a small amount from the end of the bolt as well so the metal sealing washer has a nice surface to seal on. Worked well...and has lasted about 25 years now...looks good too. You can buy the stuff from Yamaha (...well maybe?), Vanem, Deus...as the newer SRs come standard with the exhaust mount line...there are plenty of aftermarket ones from Japan etc. as well. SR  |
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Post by miker on Dec 13, 2007 9:43:25 GMT -5
Mick - adding the line reduced my top end noise but it's still plainly audible, just so you know.
miker
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Post by caferacercarl on Dec 14, 2007 2:23:10 GMT -5
A quick look under the rocker cover will show you that Yamaha has a oil passage that ran from the inlet side to the exhaust side,over the cam bearing, how clever, two feeds is not necessary and the exhaust is where it should go, noisy valve gear with correct tappet clearance indicates a "mushroomed" head on the exhaust valve,or scrubbed rockers. attention needs to be drawn to the condition of the oil pump and the right hand crank seal in the clutch cover, a mistake in these areas starves the head of oil. regards, Carl
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Post by bigshingle on Dec 14, 2007 11:16:49 GMT -5
I have an '81 500, and it has that passage too, so oil flows to the intake-side rocker arm and over the cam bearing to the exhaust-side rocker arm where there is an outlet obviously meant to let oil reach the exhaust rocker arm.
All well so far.
Both side-bolts are the same length, however, so when these are tightened down the bolt on the exhaust side goes in farther (because the oil-feed banjo on the intake works as a spacer and holds the bolt out.)
The exhaust-side bolt then blocks the oil outlet. The only oil that can get to the exhaust rocker arm has to seep past the threads. Let's say nearly zero.
I doubt Yamaha meant for the bolt to block the passage, and it may have been corrected on later bikes.
stopusingmyname, what year is your bike, and are the two side bolts the same length?
Hey, simply putting a shorter bolt on the side w/o the oil feed might do the trick!
Just the same, I'm glad to have the dual feed. I'd also like to have a double-sized feed line and a higher pressure pump if I could afford it.
Lots of oil to the top-end — that's the ticket.
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Post by bigshingle on Dec 14, 2007 11:47:00 GMT -5
Hey wait, my bad.
If you only have the stock oil feed going directly into the cover, both side bolts block the oil outlets.
So what are those outlets for? Why would Yamaha have put them there only to block them?
Fenz, I think the reason your set up has done so well all these years is that it puts lots of oil right where it would be if those holes weren't blocked.
Any ideas? This seems to be a regularly reoccurring discussion.
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