18 replies to this topic

[Swarf]

Decided to check my clearances, 6 were out but I managed to get by only having to order 2 shims. Put her all back together, turned the engine over a few times and rechecked the clearances and now 2 that were fine before have tightened up!! Anyone else ever experienced that?? I've had them out and made sure they were clean so there's no crud causing it.

[drewpy]

did you measure the shims before you put them back?

 

I always check them.

 

Could just need reseating, manually turn the engine over a few times to bed them  in

[Swarf]

Yeah, I took out all the shims (one at a time!) and measured them with a micrometer. Then when I put them back I lightly seated them with a brass drift. They were both measuring 0.15 before and now they're both 0.12. I've turned the engine over about 20 times to make sure everything was well settled. Very odd.

[Favs]

Sounds like someone may have used the wrong feeler   (this from the man who once replaced a points cam 180 degrees out & took an hour to realise why the bike wouldn't start.....  ).

[Swarf]

Classic.....😂 Its me first time doing bucket over shims too, I was quite chuffed til that point.....😠😂😂

[TYREDNGRUMPEE]

Yeah, I took out all the shims (one at a time!) and measured them with a micrometer. Then when I put them back I lightly seated them with a brass drift. They were both measuring 0.15 before and now they're both 0.12. I've turned the engine over about 20 times to make sure everything was well settled. Very odd.

 

Normally you would trust your initial measurements, maybe turn the crank once or twice using your spanner, say job done, slap it back together and go from there. Job done.

Does the manual say measure again? Does the manual say "lightly use a brass drift"?

Guessing it doesn't.

There is your problem.

 

The valves could have rotated slightly on their seats. Not a problem.

Edited by TYREDNGRUMPEE, 01 October 2016 - 01:20 pm.

[Swarf]

No, I wouldn't but after so many years building machinery I always double check everything. And the clearances are still tight, at the end of the day.

[TYREDNGRUMPEE]

 And the clearances are still tight, at the end of the day.

 

Yes. I thought so too.

When I do mine, I always aim to stretch the clearances to their maximum and I wont fret if that means going 0.01-0.02 over either.

[Swarf]

That's the way I was thinking, aye.

[Sidarta]

Yeah, I took out all the shims (one at a time!) and measured them with a micrometer. Then when I put them back I lightly seated them with a brass drift. They were both measuring 0.15 before and now they're both 0.12. I've turned the engine over about 20 times to make sure everything was well settled. Very odd.

 

Hi Swarf!

 

I do not know if the 1998 is equal to 2001 - 0.15 to 0.20 admission.
You said it had installed 0.15 and after test found 0.12.
Why do not you took to 0.20 or next(0.18 or 0.19)?

If you had left close to the maximum (0.20), have found 0.17 and need not worry so much.
I do not compensate valves and leaving at the beginning, since the trend is to close.
Try to redo the slack and test again. If you do not find the same measure, it may be that the valve seat is worn or charred.
Put your hands to work and redo everything again. Why not take the opportunity to increase this opening, since it is dismantled?

 

Shims should be installed in the seats normally. And shall go out with magnet or tweezers without resistance.

I do not understand why to use the brass drif?  

 

Cheers!

[Swarf]

Well, it was in spec originally so I left them but I won't do that again!! I've ordered two more shims so soon be sorted. The brass drift thing is purely to LIGHTLY tap the shim to seat it squarely, there's no force involved! I just noticed they sometimes sit a bit up on one side. 😊
I remove them with a magnet on the bucket. 😉

[drewpy]

I'm not a big fan of magnets, they attract swarf and maybe thats where the gap has closed up.

make sure it spotless

[Sidarta]

Hi to all!

 

Hey   drewpy, you said: ( I'm not a big fan of magnets, they attract swarf and maybe thats where the gap has closed up.

make sure it spotless)

 

Good point. I'll be careful about that, as the head of my bike is disassembled. I took him to a specialist in rectifies.

He should have entegue on Friday, but failed to comply with the commitment.

Monday will see what the excuse.

 

Cheers!

Edited by Sidarta, 02 October 2016 - 04:51 pm.

[Studley Ramrod]

Decided to check my clearances, 6 were out but I managed to get by only having to order 2 shims. Put her all back together, turned the engine over a few times and rechecked the clearances and now 2 that were fine before have tightened up!! Anyone else ever experienced that?? I've had them out and made sure they were clean so there's no crud causing it.

 

The aftermarket shims, like Hot Cam wans, can be a really tight fit and could be wedged in there.  Talking from experience.

[Swarf]

I'm not a big fan of magnets, they attract swarf and maybe thats where the gap has closed up.
make sure it spotless

 
Yep, first thing I did was remove them again and clean everything.
 

The aftermarket shims, like Hot Cam wans, can be a really tight fit and could be wedged in there.  Talking from experience.

Dunno, I'm pretty sure they're original factory ones, the ones I took out were all identical. I'm wondering if perhaps the valves hadn't seated properly, the bike hasn't run for a couple of years so maybe something was stuck. Still I'll change them and check again while the engines out.

[TKH]

Turning this to the 900. I've just checked my valve clearances (first time with shims). Cylinder 1 were all fine. Cylinder 2 has both inlets at 0.145 rather than 0.15 as minimum and exhaust both 0.215. This is slightly tighter than the minimum. Is it acceptable or too tight?

 

Also does anyone have a spare water pipe 2 4NX-12482-00 that goes from the head to the stat housing pipe (item 23 on the parts list) that they might sell? I 'kerd mine trying to get it out. Fowlers have no stock. Tried a couple of breakers and no stock so far.

 

Parts list:

https://www.fowlersp...a/radiator-hose

Edited by TKH, 08 June 2018 - 01:00 pm.

[Studley Ramrod]

Personally, I would prolly leave as is for a year, but deffo make a note of getting them done.  As you say, they are only just out of spec and not really closed up.  Mr Yamaha would prolly do the same imho.  Having said that, I accept no responsibility if yer top end siezes or loses a valve.  

 

The fact you've posted up asking might indicate that you prolly will change them though, depends on yer state of mind really, I know some peeps on here would deffo be adjusting theirs if they were a nadgers out of spec.

[dablik]

Oh he's talking about me again do them to spec, no point to open it all up again next year, do em now and have peace of mind, Studley prolly quite right but for me it would just play with me ed.

[TKH]

Thanks guys, I think you're saying what I was thinking but hoping I didn't have to do.