"Did the valve clearances on the BMW GS last night" thread in "Motorbike Chat"
Originally Posted by balbas And it was a piece of cake. I've never done them before and yet it took me less than an hour ...

Wolfzx12r · 17-06-08, 15:59

Quote:

Originally Posted by balbas

And it was a piece of cake. I've never done them before and yet it took me less than an hour from the bike being in the garage at the start of the job, to it being back in the garage and all the tools tidied away at the end of the job.

And I didn't even lose any important bits of the engine, or any tools inside the engine.

My only complaint was that I only had time to drink one cup of tea whilst I was doing the job.

Fired her up and rode to work this morning and all the valve clatter has quietened down and she's purring like she should again.

Quite how the dealers justify charging so much for a valve clearance service I have no idea. I'm loving the GS, it's so user friendly for home maintenance.

Well if you think doing the valves are that easy you can come and have a go at my Zx12, just getting your hand inbetween the 3" gap between the airbox and the top of the cam cover to take the cam cover bolts out is a nightmare on its own.

God · 17-06-08, 16:30

Quote:

Originally Posted by ipsga

twinmax+throttle balancing=piece of piss

10 minutes if all is well. usually takes me longer to take it out of the box than sort out the balance.

I don't care what you say, (but yes, Twinmax is a great bit of kit) balancing a throttle body can never be as satisfying as balancing a proper carburettor.

AbjectBlitz · 17-06-08, 20:06

Have to take my ZZR12 to get the valve clearances done... was £600 to get my old ZZR11 done few years ago, scared to think how much this time.. not sure if I should try it my self.

Mr. Dazzle · 17-06-08, 20:14

Quote:

Originally Posted by balbas

Next job is to balance the throttle bodies - seems bizarre considering it's fuel injection but there you go. I need to track down some vacuum gauges now.

Why bizarre? Both cylinders should receive the same amount of air regardless of what the method of carburetion is.

Skub · 17-06-08, 20:16

Quote:

Originally Posted by AbjectBlitz

Have to take my ZZR12 to get the valve clearances done... was £600 to get my old ZZR11 done few years ago, scared to think how much this time.. not sure if I should try it my self.

The ZZR11 was the last bike I owned where the clearances are handily done. No cams out for adjustment because the rockers slide clear of the shims. I wish my current bike was as easy. £600 is a stroke imo mate.

Foxy · 17-06-08, 20:23

Try something with a 2 valve head - even easier

Voyager · 18-06-08, 07:06

Quote:

Originally Posted by Foxy

Try something with a 2 valve head - even easier

Many years a go there was a 'keep your old Brit running' article in some bike mag that suggested twins were a daft idea as a hack bike as since there was two of everything there was twice as much to keep an eye on!

I think they had a point.

balbas · 18-06-08, 07:19

Quote:

Originally Posted by Mr. Dazzle

Why bizarre? Both cylinders should receive the same amount of air regardless of what the method of carburetion is.

Yup true of course, it's just that I tend to think of FI in terms of 'a black box what meters the fuel and air'. Being as I think of it as a black box I'd expect it to make it's own adjustments. After all, FI is supposed to be clever enough to alter the mixture for increased altitude, different air density (same thing as the altitude bit), different fuel grades, cold starting (not on mine, I also have a 'cold start' lever) and lots of other stuff. I'd just expect it to be able to work out the amount of air it was drawing into each cylinder and adjust accordingly.

But I'm wrong and it doesn't. No biggy, I like vacuum gauges anyway - they look cool on a garage wall IMO.

balbas · 18-06-08, 07:21

Quote:

Originally Posted by Wolfzx12r

Well if you think doing the valves are that easy you can come and have a go at my Zx12, just getting your hand inbetween the 3" gap between the airbox and the top of the cam cover to take the cam cover bolts out is a nightmare on its own.

No way Jose. I've played games like that before. And the skin on my knuckles wore out just before my patience. See below for the 'simple' task I carried out on a CBR 400 that cost me about half a pint of blood.

Quote:

Originally Posted by balbas

I've played that game. An ex girlfrind had a CBR400. Balancing the carbs on that required the use of a gynecologist to do some fiddly stuff inside a hole that you couldn't simultaneously see inside and have your hands inside.

Quote:

Originally Posted by ipsga

twinmax+throttle balancing=piece of piss

10 minutes if all is well. usually takes me longer to take it out of the box than sort out the balance.

Is that a recomendation for a vacuum gauge, 'the twinmax'? If so, where from and how much?

Mr. Dazzle · 18-06-08, 07:23

Quote:

Originally Posted by balbas

Yup true of course, it's just that I tend to think of FI in terms of 'a black box what meters the fuel and air'. Being as I think of it as a black box I'd expect it to make it's own adjustments. After all, FI is supposed to be clever enough to alter the mixture for increased altitude, different air density (same thing as the altitude bit), different fuel grades, cold starting (not on mine, I also have a 'cold start' lever) and lots of other stuff. I'd just expect it to be able to work out the amount of air it was drawing into each cylinder and adjust accordingly.

But I'm wrong and it doesn't. No biggy, I like vacuum gauges anyway - they look cool on a garage wall IMO.

You're right that it can self adjust for all those things, but all those adjustments are for the strength of the mixture. The volume of mixture going in is controlled by a mechanical device,the throttles, which are controlled by mechanical means, i.e. via the throttle cables, so adjustments have to be made mechanically.

Unless of course the throttles are controlled electronically, as in fly-by-wire.

PsychoBikerBen · 18-06-08, 08:03

Quote:

Originally Posted by Wolfzx12r

Well if you think doing the valves are that easy you can come and have a go at my Zx12, just getting your hand inbetween the 3" gap between the airbox and the top of the cam cover to take the cam cover bolts out is a nightmare on its own.

At least if you ever have to change the clutch on a jap bike, you've got a ten minute job. Valves may be a piece of piss on a GS but the devil shits in your face with a GS clutch change.

Rockburner · 18-06-08, 08:37

Quote:

Originally Posted by balbas

Nope. It's just happened by accident

I've played that game. An ex girlfrind had a CBR400. Balancing the carbs on that required the use of a gynecologist to do some fiddly stuff inside a hole that you couldn't simultaneously see inside and have your hands inside.

I do. I just fancied a GS to go touring on this summer, so I bought an early 1150 a few months ago.

Corrected for you.

Yes, I did notice that. That would have turned a one hour job into a weekend job I reckon - looking on the bright side it would have been a good excuse to get the clutch changed.

Next job is to balance the throttle bodies - seems bizarre considering it's fuel injection but there you go. I need to track down some vacuum gauges now.

I'm loving the tinkering with the bike feeling that owning the GS has brought back to me. It's great.

I have a manometer if you want to borrow it? (come up for a visit and do it at mine? bike has to be hot anyway).

Rockburner · 18-06-08, 08:38

Quote:

Originally Posted by God

If only you had carbs instead of that nasty fuel injection, then you'd be able to experience the joy of balancing them in minutes as well.

TB balance takes about a minute if they're not far out.

Rockburner · 18-06-08, 08:41

Quote:

Originally Posted by balbas

Is that a recomendation for a vacuum gauge, 'the twinmax'? If so, where from and how much?

Make yourself a manometer - a LOT cheaper and allegedly more accurate than the Twinmax.

balbas · 18-06-08, 08:43

Quote:

Originally Posted by Rockburner

I have a manometer if you want to borrow it? (come up for a visit and do it at mine? bike has to be hot anyway).

Thanks for the offer. 'S a hell of a way for a carb balance, but I'll give it some thought

Quote:

Originally Posted by Rockburner

Make yourself a manometer - a LOT cheaper and allegedly more accurate than the Twinmax.

How do you do that then?

17-06-08, 20:06	#18 (permalink)
AbjectBlitz Straight line hero Join Date: Jan 2008 Posts: 739 Casino cash: £198100 Thanks: 0 Thanked: 1/1	Re: Did the valve clearances on the GS last night Have to take my ZZR12 to get the valve clearances done... was £600 to get my old ZZR11 done few years ago, scared to think how much this time.. not sure if I should try it my self.
	Blitz0r'd ZZR1200 Heavyweight Power HM Government Approved Road Pirate

17-06-08, 20:23	#21 (permalink)
Foxy Senior Member Join Date: Dec 2007 Location: East Surrey Posts: 3,651 Casino cash: £160500 Blog Entries: 1 Thanks: 16 Thanked: 58/54	Re: Did the valve clearances on the GS last night Try something with a 2 valve head - even easier

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"Did the valve clearances on the BMW GS last night" thread in "Motorbike Chat" Originally Posted by balbas And it was a piece of cake. I've never done them before and yet it took me less than an hour ...

Thread Tags: bmw, bmw reliability, bmw servicing

"Did the valve clearances on the BMW GS last night" thread in "Motorbike Chat"
Originally Posted by balbas And it was a piece of cake. I've never done them before and yet it took me less than an hour ...