Servicing Valve Clearances...

I've been recommended Supreme Motorbikes (or similar) near The Imperial War Museum for getting my bike serviced and was wondering:
a) Does anyone else know them? Are they good?
b) How much I should expect to pay for a 15,000 mile service (valve clearances etc).

[timwilky]

The 15,000 mile service includes a valve clearence check. 95% of the time, no adjustment would be necassary. I would suggest that to add 1hour labour to your normal service costs should cover the check.

Only if a problem is found are you going to be into significant extra cost. (2 hours additional labour). IMHO Charging for a service to include unknown work content (re-shimming) would be a bit naughty. They should include the cost of the check and phone for an authorisation to proceed if a problem found, unless you agree up front for them to do the re-shim if a problem is found on the check.

Great news, thanks, my top end is a bit noisy at certain revs...Any idea of cost from an independent friendly type shop?

is this hard to do it yourself?

I don't have a garage, and I wouldn't attempt it on a bike. It's easy on an old car like a vw beetle but these beasties are awkward to get at and probably have twice the number of valves. Getting it wrong could be rather costly!

[Biker Biggles]

Easy to check them yourself.You just need basic tools and a feeler guage,but if you find they are needing adjustment it is quite a tricky job.You can save money by doing your own checking and only putting it in the garage if it needs doing.

What would happen to the engine if you carried on riding it with the valves not set right? Would anything get damaged or would performance just be compromised?

Would the rider notice anything, and if so, what?

Originally Posted by SVeeedy Gonzales

What would happen to the engine if you carried on riding it with the valves not set right? Would anything get damaged or would performance just be compromised?

Depends how far they're out i believe, but the answer to both is 'yes'.

[jambo]

Originally Posted by SVeeedy Gonzales

What would happen to the engine if you carried on riding it with the valves not set right? Would anything get damaged or would performance just be compromised?

Would the rider notice anything, and if so, what?

That depends on whether clearances are tight or loose.

Too loose and the valves won't open for as long, or by quite as much, they tend to sound a bit noisy at this point (although not by much, and only if they're loose by quite a bit) Engine performance will start to drop off as a result. It's not great for the engine either.

Too tight and the valves won't close as fast, or in bad cases at all, As the valve is not spending enough time tightly seated in the valve seat it can't transfer heat to the head and gets very hot. This can lead to burning valve seats and valves (that's expensive, don't do that). Also it can lead to low compression is one or more valves is not closing tightly (We are talking quite a long way out of wack at this point).

In short it's a job that you really can't tell by listening if it needs doing, it's quick to check but a bit fiddley to adjust. On my ZX6R I had to change 11 out of 16 shims at the first check and the engine felt and sounded the same. But I knew it wasn't going to eat itself.

If you're cack-handed enough adjusting the valve clearances you can dammage the head, valves, and pistons if the piston meets a valve because you put the cams back in in the wrong timing position. So make your own call on if it's something you want to do, but do get it checked on schedule.

I'd guess that short term, just performance would suffer. Longer term neglect could probably cause damage but I don't know for sure.