Valve Clearances

[SimonB]

I was having a look through my Haynes manual last night and I noticed that my bike is approaching its time to have it valve clearances checked.

So after reading through the manual and online and it seems like a time consuming process. Now I have been working on bikes for a while and I'm not too shy with my tools and quite fancy doing it myself.

So just a couple of questions so that its all clear in my head.

How long would it take a first timer to complete the job?
What parts would I need to buy to do the job?
What would happen if I didn't bother checking them and left it alone for a while?
Are there any signs that it needs doing?

Oh and the bike is a Yammy FZR600 Genesis.
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Bikes: Honda CBR250RR [sold], Yamaha FZR600 [sold], Honda CBR600RR6

[finpos]

How long depends entirely on two things:

1. How much crap you have to rip off (and replace, obv.) to get at the valves. Depending on what state it's in, factor in sheared/rounded/seized bolt time.
2. How the valves are adjusted. If any kind of shims are involved, don't count on it taking less than a day, especially as you'll need to get hold of new shims.

At a first go, it'll take you the best part of a day (but see note about shims). Shouldn't need any special tools, may need a new gasket for the cover, but I've always managed to re-use the old one.

I'd guess that there's a fair number of bikes kicking around that have not had the work done because of the effort/expense. If the adjustment is way out you get a rattly noise from the top end.

finpos.

[Walloper]

Dont do wot I do.

Buy the valve tool from the dealer.
Buy the speshal torq wench and the digital vernier.
Then remove the tank etc.
Measure clearance
Find it is perfect for another 16000 miles.
I did find a bad ignition coil tho.

It depends on the kind of bike and year.

Ask the dealer. THEY ARE OBLIGED TO tell you this.

But not a dead dead dead teki job.
You need to be sure of your 'feel' with the feelers tho.
You should be looking for a slight drag on the gauges as you pull them through the valve gap.
Too tight is not good.
If you need to adjust.
Mark each tappet as you go. Double check the nut torq before closing up shop.
If it comes slack you WILL fuck the engine.
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W-ireless A-rtificial L-ifeform L-imited to O-bservation P-eacekeeping and E-fficient R-epair

[cestrian]

So, go check your haynes manual again.

Does it mention SHIMS?
Does it mention any special tools? (with a Yamaha part number).

And although you may be quite proficient, it is worth having a technically minded friend to watch over you just in case you make a minor error. They should simply double-check each stage of the job. Things like 'valves for cylinder #1 are rocking, so which valve should we check/adjust', that sort of thing.

Good luck

[NSR Mick]

I f they are shimmed like the 1000 is checking them is fairly straight forwards.

Deciding which hims you need if you do is a different matter, I'm not sure about the 600 but the 1000's used to tighten up not slacken (mine did to the point of it not starting, finding what shims you need when you have no gap whatsoever is a bit difficult.
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If you dont like the way that I ride.......Stop trying to keep up!!!

[KatOwner]

If you are lucky ( like me )you have bikes with tappets..... undo the locknut...set the clearance...and put it all back together.

If it's shims, you have to measure the clearance...then go back to your manual and you should have a table that shows

current shim size ( stamped on if you are lucky...micrometer if not )
clearance
New shim needed.

Then, you have to trot off to your dealer and order shims of the correct size. PAIN IN THE BACKSIDE!

Of course...shims keep their clearance for sooo much longer.

[Pete.]

Never trust the etched number on a shim. I've found many that were mis-sized. Two of the ones in my current engine are marked up wrong.
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[Walloper]

You might get the shims swapped at the dealer.
Cost less than having a box of shite you might not use again.

Shop info:
Valve clearance should tighten during use.
Being the softest part of the valve train, the seats and faces of the valves wear.
This means they move further into the head and close the gap.
This is normally why they require periodic adjustment.
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W-ireless A-rtificial L-ifeform L-imited to O-bservation P-eacekeeping and E-fficient R-epair

[tony532]

slight thread hijack but i'm worried that valve clearences being checked on my thundercat are long overdue.

it doesnt state on the 24,000 mile service that they were checked.

i'm experiencing a slight ticking noise from the front of the bike,sounds like a sparkplug sparking.

i know if i take the bike into the bike garage they are going to charge me a fair bit.

should be able to take it off the road in january for a week and have a bash at doing them at work with a mate.
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bikes owned :-

aprilia rs125 - suzuki gsxr400rrsp 1990 - yamaha yzf600r thundercat - honda hornet 6

[Walloper]

I ran my Tcat to 26000 kicking arse all the way. Fcuk the valve clearance.
Your spark plug theory sounds good. (No pun intended)
But valves should be checked. I still feel guilty for not checking mine before the sale.

BTW, My only beef with my bike was the front brake caliper pistons sticking against the disc and skweelin' brakes.

It needs the calipers overhauled really. Better results than the mammoth tappetey thingy.
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W-ireless A-rtificial L-ifeform L-imited to O-bservation P-eacekeeping and E-fficient R-epair