Checking valve clearance

[MTBiker]

I just checked valve clearance as a part of maintenance before trip.
I have 22km ODO now. Measured values:
Exhaust valve 0.32mm / 0.32mm
Inlet valve 0 mm / 0mm
Now wondering what size of spacers should I order ...
Does anybody knows what kind of spacers are used in rotax ?
What standard size (height) is used ?

Thanks for any advices. Regards Lucas

 

[Losttheplot]

I just checked valve clearance as a part of maintenance before trip.
I have 22km ODO now. Measured values:
Exhaust valve 0.32mm / 0.32mm
Inlet valve 0 mm / 0mm
Now wondering what size of spacers should I order ...
Does anybody knows what kind of spacers are used in rotax ?
What standard size (height) is used ?

Thanks for any advices. Regards Lucas

Lucas,

i haven't done this job myself yet, but from what i understand, you will need to remove the existing spacers and measure these (they may be marked with their size which might make things easier).
You then take the size of the existing spacer, the current gap and the required gap, and from this you should be able to ascertain if the spacer needs replacing.

Example- your inlet gap states there is no clearance. So you take the spacer, measure it, reduce this figure by the gap in the specification, and that will give you the size of the new spacer. simples.

If your gap is to big, you just use a bigger spacer to close the tolerance up, and bring the gap back into spec.

HTH

 

[MTBiker]

Lucas,

Example- your inlet gap states there is no clearance. So you take the spacer, measure it, reduce this figure by the gap in the specification, and that will give you the size of the new spacer. simples.

If your gap is to big, you just use a bigger spacer to close the tolerance up, and bring the gap back into spec.

HTH

Losttheplot I know procedure - more or less
I just wonder is that a standard size (diameter and height) of the shim/spacer that is used by BMW|Rotax - to buy few shims not whole set at BMW dealer.
But I already get an reply at advrider.com that sim diameter is 10mm - same as KTM 950/990 - so I ordered Prox shim set - and will continue in Monday with procedure of adjusting valve clearance from RepRom.
Thanks for your time and reply

P.S
When I will take original shims out of bike I will post their height.

P.S II
Till now I have already replaced head steering bearing, wheels bearings, rear axle bearings, chain roller bearings, I have changed spark plugs for iridium ones, installed new sprockets, changed break fluid and brake pads... and still some things to be done: valves clearance adjustment, bottom cooling hose exchange, change cooling fluid, new chain install, oil exchange...
I'm wondering if I should check water pump seals - I must investigate that issue a little more.
https://picasaweb.google.com/lukasz.lechowicz/Majowo_Garazowo#

 

[Cole]

I measured my 4 originals when I had the engine apart recently, and all were 2.70 mm

 

[Losttheplot]

Seeing as the weather was shite the afternoon, and my bike is still laid up awaiting a new radiator, i thought i'd check my valve clearances.

Both exhaust valves were within tolerance, but there is no clearance at all on the inlet side.

So it looks like i need to replace those.

I presume it's a case of mark the cam position before removal, remove cam, remove top hat and change the shim underneath, then reassemble?

Would the original factory shims all be the same size- 2.7mm? what did yours turn out like MTB?

Whats the cost of shims? do you have to go to BMW, or can you go elsewhere?

Nathan

 

[MTBiker]

I drained oil, blocked crankshaft in TDC with special 'tool' (screw with a truncated end), used another 'tool' to move chain tensioner to side wall, remove shafts.
When you are removeing buckets shimms are 'glued' undernetht to them.
AFIR mine shims orginally were 2,70mm and 2,65mm
I just bought whole simm set from Proxx dealer - 10mm diameter (for KTM 690/990)

 

[frostyuk]

Hi Nathan

copied this from advrider

"G650X Rotax valve shims are 10mm diameter, and come in 0.05mm variations in thickness. You might want to measure the thickness of your current shim, and maybe get 1-2 sizes smaller to try on.

Or measure everything up real carefully, valve clearances with buckets without shim, take notice of all the valve seating heights, etc. calculate differences and come up with probabble thicknesses for your need (and most likely come up with needing 1-2 sizes thinner anyways


Here's the part # listing.

Thickness / BMW part#
2.30mm 11327675540
2.35mm 11327675542
2.40mm 11327675707
2.45mm 11327675709
2.50mm 11327675711
2.55mm 11327675713
2.60mm 11327675715
2.65mm 11327675717
2.70mm 11327675719
2.75mm 11327675777
2.80mm 11327675779
2.85mm 11327675781
2.90mm 11327675783
2.95mm 11327675785
3.00mm 11327675787


If you have local shops nearby, the same diameter (10mm) applicable valve shims are also used in KTM 950/990 series, and Harley-Davidson V-ROD. Harleys have 10mm OD shims in 0.025mm variations even. And, 9.8mm diameter shims off of Benelli are known to have been used in a pinch, as well."

 

[Losttheplot]

Thanks for that frosty

What are you all using to measure shim thickness with? i don't have a micrometer, but i have got some digital callipers which seem to be pretty consistent and accurate- good enough?

 

[Losttheplot]

Right, it looks like i have the shim supply sorted

Now how to get them out?

I've just had another look at it all. I presume the timing chain has to come off?

Or is it possible to zip tie the chain to the cam sprockets (as per steptoe's 1150 head gasket thread), remove the tensioner and lift the cams off the head enough to get the buckets and shims out?

Any pointers towards a workshop manual would be a great help at this moment in time

 

[frostyuk]

link to the reprom in here

http://www.ukgser.com/forums/showthread.php?t=207191

 

[Losttheplot]

link to the reprom in here

http://www.ukgser.com/forums/showthread.php?t=207191

Thanks frosty!

I found it this morning just after i posted. Workshop manual is now on dvd.

The job actually looks reasonably straight forward- and it looks like the whole engine has been thought out to make servicing easy.

To find TDC there is a bolt in the bottom of the crankcase- you take this out and put a longer bolt in, when the motor is at TDC you wind this bolt in a little further and it locks the crank.

You can the strip the top end ( push bank the camchain tensioner first), and get at the valve shims.

I'd try and take some photo's if i remember

 

[rossi]

If it is the same locking bolt that I used to have for my rotax 604 engined CCM it is pointed at 45 degrees but with a flat tip at the end. I think I passed my locking bolt on when I sold the CCM, at least I can't find it now. Anyway I filed the end of an M8 bolt to a point and it locks the crank perfectly.

My exhaust valves are all loose on .33, inlets used to be tight on .05 but I can't get it in there now (I don't have a .03 gauge). I measured the shims with a micrometer but it is imperial rather than metric (passed down from my Grandfather who used to work on aero engines). Converting from thou to mm the shims come out as 2.55 and 2.6. I could grind down the inlet shims but since I will need to order a larger shim for one of the exhaust valves I might as well order 2 shims for the inlets as well.

 

[Losttheplot]

If it is the same locking bolt that I used to have for my rotax 604 engined CCM

Probably not, this bolt came straight out of a new packet in my tool box


I did think about grinding down the original shims, but considering the size, and the hardness of the steel, i decided it wasn't worth the hassle.

 

[Deleted account 190117001]

Locking the crank

You don't need a special bolt to lock the crank,
one is supplied fitted to the bike.

Remove this bolt.(either side will do )

Like this.

Screw it in here when you see the slot in the crank with a torch.

You need to screw the bolt in gently by hand and you will feel it locate.


Do not use this bolt to lock the engine in order to undo any fasteners on the engine.
It will snap and you will have a piece of bolt rattling round the bottom of your engine.
Only use it to set your valve timing after a rebuild or checking valve clearance and re-shimming.

I hope someone finds this useful.

 

[rossi]

The larger shim had to be ordered from Germany. Just as well I don't need the bike for a couple of days. Also coming from Germany is the yellow plastic cam chain guide as this cracked as I removed the two bolts, dropping a piece of plastic down into the engine. Fortunately it landed on top of the timing chain drive socket and I was able to retrieve it with a grabber borrowed from a mechanic friend.