Valve clearances

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#1 Post by **mangocrazy** » Fri Mar 14, 2014 10:50 pm

I'm just about to check the valve clearances on the blue Falco (03 plate, approx 30k miles) and am not sure what I'm likely to find. I'm not bothered about checking them - I already have the throttle bodies off; it's just what the procedure is if any are out of spec that I can't seem to establish.

I have all the manuals in softcopy format (Workshop Manual, engine manual, owners manual), but can't find a section in any of them that goes through the process to follow to check them and what to do if the clearances are out of spec.

Am I missing something, or just over-thinking it?

HisNibbs · #2 Post by **HisNibbs** » Fri Mar 14, 2014 11:05 pm

Cross that bridge when you come to it. (Probably it won't be necessary to re shim)

#3 Post by **mangocrazy** » Fri Mar 14, 2014 11:08 pm

HisNibbs wrote:Cross that bridge when you come to it. (Probably it won't be necessary to re shim)

Yeah, that's what Im hoping. Should know tomorrow.

D-Rider · #4 Post by **D-Rider** » Sat Mar 15, 2014 2:04 pm

Ken's site will help

http://home.comcast.net/~sl_mille/valves.html

#5 Post by **mangocrazy** » Sat Mar 15, 2014 4:03 pm

Having started to measure the clearances, I now realise that the set of metric feeler gauges I have isn't precise enough - they only increment in 0.05mm steps, and I really need gauges that can measure down to 0.01mm. The 0.25mm gauge will absolutely not fit between exhaust cam and bucket, but a 0.20mm will slide in quite nicely. Likewise a 0.15mm gauge will not fit 'twixt inlet cam and bucket, whereas a 0.10mm gauge will.

I suspect that even if they are within tolerance, they will be right on the limit of acceptability. But I'll reserve final judgement until I've got a new set of metric feeler gauges. These are the ones I've gone for:

http://www.ebay.co.uk/itm/Yato-professi ... 1154013461?

#6 Post by **mangocrazy** » Sat Mar 15, 2014 4:19 pm

D-Rider wrote:Ken's site will help

http://home.comcast.net/~sl_mille/valves.html

Thanks Andy, that's a very nice write-up. I feel a lot less apprehensive about the whole thing having read that. I like his idea of cable tying the cam chain to the sprockets. Smart idea.

D-Rider · #7 Post by **D-Rider** » Sat Mar 15, 2014 10:05 pm

mangocrazy wrote: The 25mm gauge will absolutely not fit between exhaust cam and bucket,

That's just as well - I bet it weighs quite a bit though and probably quite difficult to flex.

mangocrazy wrote:but a 20mm will slide in quite nicely.

That sounds very worrying !!

#8 Post by **mangocrazy** » Sat Mar 15, 2014 10:39 pm

D-Rider wrote:
mangocrazy wrote: The 25mm gauge will absolutely not fit between exhaust cam and bucket,
That's just as well - I bet it weighs quite a bit though and probably quite difficult to flex.

mangocrazy wrote:but a 20mm will slide in quite nicely.
That sounds very worrying !!

Yes - well spotted. Changed to make sense now...

#9 Post by **mangocrazy** » Thu Mar 27, 2014 10:40 pm

Finally got a set of feeler gauges that measure down to 0.01mm increments, and these are the measurements (L is nearside, R is offside):

Front head:

Exhaust

L - 0.24mm R - 0.26mm

Inlet

L - 0.10mm R - 0.14mm

Rear Head

Inlet

L - 0.13mm R - 0.11mm

Exhaust

L - 0.23mm R - 0.24mm

So - all apart from 2 inlet valves within spec. I've double checked this with Griff, and the two inlets in red are definitely too tight. The front head, despite being less accessible, is actually easier to do, as it doesn't have the balance shaft (the rear does). But it does have a fiendishly difficult to access cam-chain-tensioner-pressure-releaser bolt...

Griff reckons you can undo it with a long ball-ended allen key; I fail to see how that is possible. I tried inserted such a device in it, and the angle of attack from above is about 45 degrees off centre. Even ball-ended allen keys can't manage that. Any ideas how to undo this bloody thing?

I undid the rear cylinder tensioner bolt without too much difficulty, but the problem now is how to get the cam bearing covers off. I've undone the 8 allen bolts and removed the nylon guide with its 2 10mm head bolts, but nothing wants to move. Do I need to undo the big nut on the end of the balance shaft and its gear? I really rather hope not...

#10 Post by **mangocrazy** » Mon Mar 31, 2014 9:58 pm

The tale of woe continues. I'd pretty much resigned myself to handing it over to Griff to do the valve clearances, and started looking at other stuff. While poking about I noticed that both rads were a bit loose (and off centre). Closer investigation revealed that the top mounts have sheared off on both rads (they appear to be glued or bonded on) as a result of accident damage (or ham-fistedness, can't decide which). Which means they will leak. Which means they've had to come off so I can get them ali welded. Oh joy.

The off-centredness was due to the radiator support bracket being bent out of square and one of the retaining pins on the bottom tank being misaligned. I managed to get the bracket back to almost square, and the guy who's doing the ali welding will also get the pin squared up.

With the rads off I had much better access to the front head and following a phone call to Griff (and the knowledge that there is a way to lock the crank so the valve gear doesn't move while the cams and balance shaft on the rear head are out) emboldened me to try again. I also managed to find a way of getting the sprockets sufficiently out of the way that I could undo the two M6 bolts that are behind the sprockets. It was a major faff, but the balance shaft and cam holders all came out in one piece.

And at last I could get the inlet cam out and mic up the shim. It was a 0.285mm shim (same as the front inlet valve that was tight), so a pair of 0.280mm shims will be on order from Griff first thing tomorrow morning. Perhaps some time in the next week or so I can start putting things back together instead of stripping it further and further down...

D-Rider · #11 Post by **D-Rider** » Mon Mar 31, 2014 10:09 pm

When I checked my valve clearances they were all within spec - but a couple of them were very close to the limit.
Knowing they don't move much, I was happy to leave it. I made a mental note that next time they would probably need doing and that unless I've a lot of time on my hands and a better garage/workshop sorted, then it'll be shipped over to Griff to be sorted.

Though if I'm paying him to take the thing apart and fettle it, it might be the time to bung one of his 1060 kits in (I think the Spoonvalley 1127 kits are a bit too spendy)

#12 Post by **mangocrazy** » Mon Mar 31, 2014 10:13 pm

Blimey Andy - how much will that cost (and for what benefit?) I'm sure it will pep the old girl up, but they're not exactly short of juice in standard trim...

#13 Post by **mangocrazy** » Wed Apr 02, 2014 10:21 pm

A pair of 0.2800 mm shims arrived in the post from Griff this morning and tonight I screwed my courage up into a little ball and started rebuilding the rear head. Magnetic probe at the ready - check. Loctite 243 - check. Isopropyl alcohol for cleaning duties - check. Molykote GN for cams/buckets - check. Torque wrench - check.

Amazingly, everything went back very smoothly. Equally amazingly, all my marks in indelible felt tip pen lined up, and it was all reassembled with lots of squirts of Motul 5100 from the oil can, and careful application of Loctite 243 where necessary. Everything torqued up nicely - 11Nm for all the internal M6 bolts/cap head screws, 50 NM for the balance shaft gear nut that I'd unnecessarily removed, and 9 Nm for the rocker cover M6 cap head screws.

Tomorrow - the front head...

D-Rider · #14 Post by **D-Rider** » Wed Apr 02, 2014 11:41 pm

mangocrazy wrote:Blimey Andy - how much will that cost (and for what benefit?) I'm sure it will pep the old girl up, but they're not exactly short of juice in standard trim...

Depends how "flush" I am. I know what it'll cost and if I take off the cost of a service (as it will effectively get one when being rebuilt) - including valve re-shim, plus dyno time to set up a the PCIII (on top of the Gabro) - then the cost of bunging in the big cubes isn't really that bad.

I know I've always said the Falco has more than enough power - which it does ...... however, each of the last couple of summers there have been occasions when I've been trying to wind it on and found I've used up all that's there.

Worth doing / value for money for my average ride? Not a chance.
However, the engineer and fettler in me that says "you know it can be done" is a powerful force ..........

My task is to try to keep those voices down .... but I might loose ...

mrapriliafalco · #15 Post by **mrapriliafalco** » Thu Apr 03, 2014 9:48 am

Reading about the new RSV4, they reckoned a valve clearance service will be heart attack material