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Kawasaki Jimbo
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PostPosted: 23:12 - 10 Oct 2018    Post subject: Valve clearances. Reply with quote

I tend to do my own servicing these days but apart from oil and spark plug changes the engine block and cylinder head are a bit of a mystery to me. Some time ago a bike shop I trust said they don't look at valve clearances unless there are indications. My two bikes start and run fine but still I wonder if damage is occurring. Should I worry?
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Old Git Racing
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PostPosted: 23:17 - 10 Oct 2018    Post subject: Reply with quote

depends what they mean by indications. Valve burning out? Loss of compression? Best bet is to check them at the specified intervals then you dont get any 'indications'. They probably don't know how to do it, don't trust them, get another shop or do it your self, it's easy enough.

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Riejufixing
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PostPosted: 00:30 - 11 Oct 2018    Post subject: Re: Valve clearances. Reply with quote

Kawasaki Jimbo wrote:
I tend to do my own servicing these days but apart from oil and spark plug changes the engine block and cylinder head are a bit of a mystery to me. Some time ago a bike shop I trust said they don't look at valve clearances unless there are indications. My two bikes start and run fine but still I wonder if damage is occurring. Should I worry?


I wouldn't worry, but I'd check them. Find out how to position the engine correctly in its cycle, get the lid off, measure the clearances, fix if need be, it's not difficult, but you may have to get other bits off for access.

If they're slack, probably the only thing you'll notice is a light tickety-tickety-tickety top end noise.

If they're too tight, performance will drop off, soon you'll get overheating, and in extreme cases the fuel in your carbs will boil, and your exhausts will be seen glowing cherry-red when it gets dark after you've struggled on all day long to go 150 hard miles wondering what the hell's wrong with the poxy thing and stopping to piddle about with it and let it cool down every few miles and you're still only halfway home, and you'll suddenly remember that the bloke at the Wheel & Wings Truro mentioned "the tappets do themselves up" but you'd forgotten and THAT is why the thing's red-hot and you will adjust the things in the morning after kipping all night in a cold derelict house on rusty bunk-beds with your mum and sisters who'd been following you in a car all the way and blocking their ears up at the language and when you finally get home next day you'll take it apart and look at the valves and they will look as though a mouse has nibbled a deep cheese-segment-shaped notch out of the outside of the dratted things and you'll wonder how the hell it worked at all and you will never forget about it. Grrr!
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A100man
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PostPosted: 11:32 - 11 Oct 2018    Post subject: Re: Valve clearances. Reply with quote

Riejufixing wrote:


If they're too tight, performance will drop off, soon you'll get overheating, and in extreme cases the fuel in your carbs will boil, and your exhausts will be seen glowing cherry-red when it gets dark after you've struggled on all day long to go 150 hard miles wondering what the hell's wrong with the poxy thing and stopping to piddle about with it and let it cool down every few miles and you're still only halfway home, and you'll suddenly remember that the bloke at the Wheel & Wings Truro mentioned "the tappets do themselves up" but you'd forgotten and THAT is why the thing's red-hot and you will adjust the things in the morning after kipping all night in a cold derelict house on rusty bunk-beds with your mum and sisters who'd been following you in a car all the way and blocking their ears up at the language and when you finally get home next day you'll take it apart and look at the valves and they will look as though a mouse has nibbled a deep cheese-segment-shaped notch out of the outside of the dratted things and you'll wonder how the hell it worked at all and you will never forget about it. Grrr!


Painting pictures with words.. glad you're almost over it now though. Neutral
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Kawasaki Jimbo
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PostPosted: 12:27 - 11 Oct 2018    Post subject: Re: Valve clearances. Reply with quote

Riejufixing wrote:
I wouldn't worry, Cool

Riejufixing wrote:
WORRY!!! Praying Rain Exclamation

Good one though. Laughing Thumbs Up
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DrSnoosnoo
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PostPosted: 12:58 - 11 Oct 2018    Post subject: Reply with quote

It's not hard. I went from never using a ratchet to valve clearances in a year. Didn't blow up.

Get a Haynes, get some time and just have a go.
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GT200Fan79
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PostPosted: 13:05 - 11 Oct 2018    Post subject: Reply with quote

I donít do shim type clearances myself, Iím a decent mechanic but itís a shop job for me (or I just make sure all my bikes have screw and lock nut tappets).
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BusterGonads
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PostPosted: 14:07 - 11 Oct 2018    Post subject: Re: Valve clearances. Reply with quote

Riejufixing wrote:

If they're too tight, performance will drop off, soon you'll get overheating, and in extreme cases the fuel in your carbs will boil, and your exhausts will be seen glowing cherry-red when it gets dark after you've struggled on all day long to go 150 hard miles wondering what the hell's wrong with the poxy thing and stopping to piddle about with it and let it cool down every few miles and you're still only halfway home, and you'll suddenly remember that the bloke at the Wheel & Wings Truro mentioned "the tappets do themselves up" but you'd forgotten and THAT is why the thing's red-hot and you will adjust the things in the morning after kipping all night in a cold derelict house on rusty bunk-beds with your mum and sisters who'd been following you in a car all the way and blocking their ears up at the language and when you finally get home next day you'll take it apart and look at the valves and they will look as though a mouse has nibbled a deep cheese-segment-shaped notch out of the outside of the dratted things and you'll wonder how the hell it worked at all and you will never forget about it. Grrr!


Happened to me that back in 1972/3 when I'd stupidly been pissing about with the carb needle on my BSA A10. Weakened it to save petrol and burned a valve. Half way up the A1 between London and Newcastle the thing had a red hot pipe and terrible performance. Since it had one of those bomb shaped side cars on with my girl friend in and all our worldly goods I was in REAL trouble. Did I mention it was the middle of the night? That's how we noticed the red hot pipe. What a trauma that was. This is why my advice to young lads is don't meddle with what you don't understand. Nearly all my 1970s break downs were caused by my own stupid meddling.

Like you say - a nasty slice of cake shaped piece missing from the valve when I took he head off. Fortunately valve seats were recoverable with some grinding paste - no re-cutting needed.
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BusterGonads
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PostPosted: 14:10 - 11 Oct 2018    Post subject: Reply with quote

A useful tip is that once you've made the adjustment and tightened the lock nut, check the gap again. Tightening the lock nut can often nip up the gap a bit and usually too much. Also, turn the engine on for two full revolutions and check again.
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Riejufixing
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PostPosted: 15:13 - 11 Oct 2018    Post subject: Re: Valve clearances. Reply with quote

BusterGonads wrote:
Riejufixing wrote:

If they're too tight, performance will drop off, soon you'll get overheating, and in extreme cases the fuel in your carbs will boil, and your exhausts will be seen glowing cherry-red when it gets dark after you've struggled on all day long to go 150 hard miles wondering what the hell's wrong with the poxy thing and stopping to piddle about with it and let it cool down every few miles and you're still only halfway home, and you'll suddenly remember that the bloke at the Wheel & Wings Truro mentioned "the tappets do themselves up" but you'd forgotten and THAT is why the thing's red-hot and you will adjust the things in the morning after kipping all night in a cold derelict house on rusty bunk-beds with your mum and sisters who'd been following you in a car all the way and blocking their ears up at the language and when you finally get home next day you'll take it apart and look at the valves and they will look as though a mouse has nibbled a deep cheese-segment-shaped notch out of the outside of the dratted things and you'll wonder how the hell it worked at all and you will never forget about it. Grrr!


Happened to me that back in 1972/3 when I'd stupidly been pissing about with the carb needle on my BSA A10. Weakened it to save petrol and burned a valve. Half way up the A1 between London and Newcastle the thing had a red hot pipe and terrible performance. Since it had one of those bomb shaped side cars on with my girl friend in and all our worldly goods I was in REAL trouble. Did I mention it was the middle of the night? That's how we noticed the red hot pipe. What a trauma that was. This is why my advice to young lads is don't meddle with what you don't understand. Nearly all my 1970s break downs were caused by my own stupid meddling.

Like you say - a nasty slice of cake shaped piece missing from the valve when I took he head off. Fortunately valve seats were recoverable with some grinding paste - no re-cutting needed.


You too, huh? My first "breakdown" of the day was after about 15 miles, up on Davidstow moor. Oakhill, near Shepton Mallet, was reached after dozens and dozens of stops in about 10 hours. I'd even resorted to cutting up old tins from the hedge to make heat shields for the carbs. That was an outfit too, with a huge double-adult sidecar with another smaller body inside it. Anyway.
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Enduro Numpty
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PostPosted: 17:05 - 11 Oct 2018    Post subject: Reply with quote

Old Git Racing wrote:
depends what they mean by indications. Valve burning out? Loss of compression? Best bet is to check them at the specified intervals then you dont get any 'indications'. They probably don't know how to do it, don't trust them, get another shop or do it your self, it's easy enough.

OGR.


As Above.

If you're not going to do it yourself find another bike shop that doesn't wait till your engines broken before checking/adjusting valve clearances. Manufacturers don't create service intervals for fun. You may get away with it, then again you may not! When my FJR1300 was coming up for it's first valve service I asked the advice of a bike dealer on the procedure and according to him, "the FJR is a big, low revving engine and the valves clearances never change" he said that if he got one in to service he wouldn't bother. I ignored his "advice" and while it was a major faff about removing all the obstructions to actually get to checking the clearances, when I did I found that 3 out of the 16 were slightly tight and re-shimmed accordingly. Fast forward 24K miles and next valve service and all were in spec.

Get yourself a manual and the tools to do it. Understand what you're doing and if there's a clearly stated procedure then follow it. The cost of any tools you need will be considerably less than the cost of a dealer doing (or not doing) the service.
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BusterGonads
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PostPosted: 18:19 - 11 Oct 2018    Post subject: Re: Valve clearances. Reply with quote

Riejufixing wrote:


You too, huh? My first "breakdown" of the day was after about 15 miles, up on Davidstow moor. Oakhill, near Shepton Mallet, was reached after dozens and dozens of stops in about 10 hours. I'd even resorted to cutting up old tins from the hedge to make heat shields for the carbs. That was an outfit too, with a huge double-adult sidecar with another smaller body inside it. Anyway.


Ha ha ha - happy days eh? The breakdowns were legion. I was once reduced to scratting about in a lay by in the dark looking for discarded match sticks so I could stuff them into the magneto cam screw holes after the securing screws had worked loose and disappeared on the A1. The A10 magneto had a stationary cam secured by two small bolts and the contact breaker rotated around inside it. I found a couple of small wood screws in the back of the sidecar by groping in the dark and realised that if I could stuff some match sticks in the holes, I could get these little screws to hold the thing on in some semblance of timing. It was well off, but I did get it home, popping and banging, but still making some power to get along.

I once had a big double adult sidecar as well, but I got rid of it for one of those more modern bomb shaped ones. It was still rubbish, but it looked a bit cooler. Smile
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ThatDippyTwat
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PostPosted: 21:23 - 11 Oct 2018    Post subject: Re: Valve clearances. Reply with quote

Kawasaki Jimbo wrote:
don't look at valve clearances unless there are indications.


If you're running a gear driven VFR - fair enough. Otherwise, I'd have a check at prudent intervals. Not necessarily specified mileages, but sensible ones.
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Pigeon
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PostPosted: 21:31 - 11 Oct 2018    Post subject: Reply with quote

DrSnoosnoo wrote:
It's not hard. I went from never using a ratchet to valve clearances in a year. Didn't blow up.



+1

The main ballache on modern bikes is clearance to other shite (like frame and radiator). Some bikes seem to be designed to make it impossible to get decent access.
Then the other worry is dropping something into the engine. A dowl coming loose at the wrong point etc
Try to mitigate with rags and magnetic sticks, but meh, it could still happen.


Ultimately, unless I 100% trusted the garage or asked them for photos as they did the job (potentially insulting) then I'd do it myself or not at all.
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rhys99
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PostPosted: 21:31 - 11 Oct 2018    Post subject: Reply with quote

why wouldn't they check them? it makes them money so theres no reason why they shouldn't be checking them. From what i've seen most bikes don't need shimming until 25k+
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Nobby the Bastard
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PostPosted: 21:48 - 11 Oct 2018    Post subject: Reply with quote

rhys99 wrote:
why wouldn't they check them? it makes them money so theres no reason why they shouldn't be checking them. From what i've seen most bikes don't need shimming until 25k+


Cause it's a fucking ballache to do. At best it means removing the radiator to get the access.

The best indicator of clearences getting too tight is the bike not starting until it's warmed up but then runs fine.
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Fizzer Thou
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PostPosted: 09:52 - 12 Oct 2018    Post subject: Reply with quote

Nobby the Bastard wrote:
The best indicator of clearences getting too tight is the bike not starting until it's warmed up but then runs fine.


Really???

Surely,if the clearances are too tight then compression would be reduced and would be difficult to start from cold and even worse once hot,as the valves would be held open even more Rolling Eyes
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Fizzer Thou
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PostPosted: 10:08 - 12 Oct 2018    Post subject: Reply with quote

I have heard on a number of occasions that bike shops have charged multiples of £100 to check valve clearances and not even bothering to remove the cam cover...yet have furnished the customer with a printout of the supposed measurements.Not the done thing but reading this post I would not put it past some places making a quick buck and charging for work not actually done Thumbs Down Evil or Very Mad Thumbs Down

In the old days of threaded adjusters (still used on my KTM enduro) it was relatively easy to check and adjust.Nowadays,with shim under bucket,this involves removing the cam(s) so as to access the shims.As this needs to be done with the engine cold and the bike has not long been dropped off for this service,accurate measurement of the clearances,if they were to be checked,would not always be possible.

The first bike that I owned (and still own) that has shims is the Exup1000.This engine has the shims under the inverted bucket and so,with the closeness of the frame,is not that easy.Just to measure the clearances is not that easy.But once all twenty were measured,I then had to pull the cams so as to check the size of the shims installed.Take into account that a shop has a fixed time for such jobs and it can be seen why corners are cut.
But once it was all sorted and eleven of the twenty were changed,the engine ran much better.The main problem was realigning the crankshaft to the cams,having to look through a small hole in the crankcase to check the markings.Then getting the cams bolted back down accurately without being even one tooth out.

When I rebuilt the FJ1200 I found it easier to pull both cams as fourteen of the sixteen shims needed changing.Like the FJR1300 it is a slow reving engine,but the service intervals are a lot more frequent compared to the Exup or the R1.

Having a clear worktop,a micrometer and a magnet are the best way to start the job.Do not forget to make a note of the shims fitted so that you know where to start from the next time around Thumbs Up Wink

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Last edited by Fizzer Thou on 12:39 - 15 Oct 2018; edited 1 time in total
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doggone
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PostPosted: 10:54 - 12 Oct 2018    Post subject: Reply with quote

Threaded adjusters with locknuts were easy enough to do yourself - but just as well because they soon drifted out.
With shims most bikes now will go to at least 20,000 miles with no need to do anything unless starting performance is deteriorating.
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Tdibs
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PostPosted: 12:34 - 12 Oct 2018    Post subject: Reply with quote

I would time it with a coolant change as dropping the rad (might) make it easier, depends on the bike. With the power of haynes and a feeler gauge you should be able to measure the clearances. Then once you have the information you can decide where to go from there. If it needs re-shimming I would be inclined to find a decent independent place with good reviews if you feel its too much. Other case is they are in spec and no adjustment needed.

Not always a bad shout to order a new valve cover gasket just incase your current not in good shape.
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BusterGonads
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PostPosted: 12:53 - 12 Oct 2018    Post subject: Re: Valve clearances. Reply with quote

ThatDippyTwat wrote:
Kawasaki Jimbo wrote:
don't look at valve clearances unless there are indications.


If you're running a gear driven VFR - fair enough. Otherwise, I'd have a check at prudent intervals. Not necessarily specified mileages, but sensible ones.


I'm under the impression that most clearances decrease as the valve seats and faces wear. This means the valve clearances gradually tighten up and won't make noise. As the engine comes to running temperature any clearances are taken up and a tight valve will start to leak because it can't seat properly. I wouldn't want that, so you are right to warn that they should be checked. Burned valves are no fun at all. Even having to grind valves in is a pain in the arse when you could be riding instead.
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BusterGonads
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PostPosted: 12:58 - 12 Oct 2018    Post subject: Reply with quote

Fizzer Thou wrote:
Nobby the Bastard wrote:
The best indicator of clearences getting too tight is the bike not starting until it's warmed up but then runs fine.


Really???

Surely,if the clearances are too tight then compression would be reduced and would be difficult to start from cold and even worse once hot,as the valves would be held open even more Rolling Eyes


And passing high energy combustion gases across the gap, taking away valve face and seat material. If the clearances are tight enough to affect performance, the valves and seats are being eaten.
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Nobby the Bastard
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PostPosted: 13:20 - 12 Oct 2018    Post subject: Reply with quote

Fizzer Thou wrote:
Nobby the Bastard wrote:
The best indicator of clearences getting too tight is the bike not starting until it's warmed up but then runs fine.


Really???

Surely,if the clearances are too tight then compression would be reduced and would be difficult to start from cold and even worse once hot,as the valves would be held open even more Rolling Eyes


Really. The head typically expands more than the valves (different metals) and so the clearances open up as the head warms up.

Yes, it will be a bastard to start, but as fuel burns it warms up and will suddenly start and then work fine until it gets a chance to cool down.
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bikenut
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PostPosted: 13:49 - 12 Oct 2018    Post subject: clearance Reply with quote

The bikes maker quotes service intervals for a reason.

Has your bike got haudraulic cam followers or auto adjust in the system, valve working clearance wise, the slang being tappet clearance or tappets ( see FORD ) .

Your name suggests its a kawasaki, see cmsnl for the exploded views whioch will tell you if its bucket shims under the bucket, or, ala suzi gizzer, or screws/nuts...etc.....and go from there.

If you have a tight clearance then you run the very real risk of burning, a costly mistake, or a slack clearance you will hear, again a relatively costly mistake.

You can change the oil and filter as well as plugs, so do some research and see whats involved before you start taking the bike/engine apart.......

Some bikes are dead easy, others more difficult and some very difficult indeed being very involved needing many special tools and procedures......

Do the research first.
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Fizzer Thou
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PostPosted: 10:31 - 13 Oct 2018    Post subject: Reply with quote

Nobby the Bastard wrote:
Really. The head typically expands more than the valves (different metals) and so the clearances open up as the head warms up.
Yes, it will be a bastard to start, but as fuel burns it warms up and will suddenly start and then work fine until it gets a chance to cool down.

WHAT!!!!!

All metals expand as they heat up.If there is little or no valve clearance as the engine gets hotter the valves will be held open.

You really do need to read what you have posted.It does not follow at all Shocked Rolling Eyes Thumbs Down
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