Checking valves on a double overhead cam italian

[msbuck]

I am SO SPOILED with my airhead!  It's such a breeze to check and adjust the valves on my R65, but now I'm trying to CHECK the valves on my 1998 Laverda Ghost Strike.  Man, am I ever confused!  I think I don't have to worry about TDC on this like I do the BMW, but I'm not really sure.  I do have the manual, but it doesn't always tell you everything you need to know.  

So we're checking the valves with the lobes on the cam opposite the tappets for the correct clearances - regardless of where the piston is.  Does this sound right to anyone out there that has experience with this?  I think the Intakes are fine, but it seems like the exhaust clearances are too tight.  This somehow doesn't seem right.  It is shim under bucket type adjustments and I REALLY don't want to have to go there....

Any advice, suggestions, comments greatly appreciated.  

[Bob_Roller]

If the lobes on the cam are 180 degrees from the cam followers that should be adequate, the valves aren't going to get any more closed than that.

Don't know anything about Laverdas, but is retorquing the head something to do before checking the valve clearance ?

I've never adjusted shims under bucket type valve train, but you have to measure your present clearance, remove the cams and cam followers measure the current shims, and then install new shims of the correct thickness.

A lot of work compared to performing the same job on a R65 !

[Ed Miller]

snip
Don't know anything about Laverdas, but is retorquing the head something to do before checking the valve clearance ?

snip

Msbuck, do you have a manual for that bike?

I don't think the head torque would make much difference if that's an overhead cam bike.  

[msbuck]

Thanks guys.  Yes, we have the factory manual and we have already retorqued the head.  This engine had a new crank put in just 6k ago and it was completely apart, so I figured we should go ahead and retorque.  It definitely needed it!  I'm not sure it would really make a difference either but it's done just the same.

I feel better about our measurements, but I sure don't want to dig into this project.  The spec on the exhaust valves is .30-.35mm (or about 12 in BMW terms).  They measure the same as the intake at .20mm (or about which is right on spec for the intakes.  It's so easy on the BMW I wouldn't think about NOT correcting, but with these I am second guessing just how important this task is.  If these valves have never had to be adjusted before, we were thinking that there would not be any skims in place at this point.  But, from your description it sounds like shims should be there.  We didn't understand how we could make the clearance wider if there were no shims to remove.  

So it sounds like we will have to remove shims already in place (?) and find shims thinner (of the correct thickness) to correct the clearances....does all this sound right?   :-/

[Bob_Roller]

That sounds right, measure your current clearance, then use a micrometer to check the thickness of the shims that are in there, then get shims of the correct thickness.

Like I said before, I don't know anything about your make of bike, and not to make you paranoid, but it sounds like the problem with the early '80's airheads have with valve recession.

I would try to get more information from a reliable source on the valve clearance closing up.
 

I had a co-worker that had a '91 K100, and he had to buy a $200 set of shims for his bike, when it came time to adjust his valves, but the bike had 95,000 miles on it when it finally needed to be done.

[Justin B.]

I believe the volvo red-block engines in the 240 series are also adjusted this way.  You measure lash, pull out the shim(s), do the math, and insert correct thickness of shim(s).  You may check with a few of the clubs that cater to these bikes as they might have a "shim kit" that members can "borrow", and only have to pay for the shims they actually use.

[nhmaf]

You might need a special set of pliers and/or pick-type tool to remove the shims - often one has to depress them somewhat against the valve spring pressure
and pull them out, but I've never worked on a Laverda before, only Kawasakis.  When you do your calculations, you may well end up with a shim thickness
that is in between what the available standard thickness shims are for your bike in the kit.  If this happens, it is usually best to pick the one that gives slightly
more clearance - valves very seldom get looser as time goes by.  Exhaust valves almost always ever so slowly tighten up, and sometimes
I've seen intake valves loosen up due to deposits buildup on the valve/seat.  The shims themselves are generally made of hardened tool steel to resist wear, though
in some cases, they can wear down slightly, particularly if they haven't been made well and the hardening is only on the outside of the steel and doesn't go deep into the steel.

Some bikes use the same type/size of shim, but I have no idea about Laverdas, sorry !  I noticed that there was a Laverda shim kit for sale on ebay for $300,
but it appears that this is only for the older bikes up to the Jota.

Best of luck - I am sure that you guys can do this, once you find the parts you need !

[MrRiden]

You might need a special set of pliers and/or pick-type tool to remove the shims - often one has to depress them somewhat against the valve spring pressure
and pull them out,

when depressing the shim "bucket" to remove / replace the shims be aware of the piston position. You don't want to be mashing the valve into the piston top. as for measuring clearance it is ok to ignore the piston position as long as the cam lobe is 180deg from the shim! Good luck!
rich

[suecanada]

Aïda, I do sympathize with you and I have been in the same "unknown" territory with the F650GS. Shims??? What??? We sure are spoiled with our boxers. The F650GS single I have sold now..the one I had in Raleigh back in '06, is in the shop getting its valves checked for the new owner. I never did check them myself in the 21,000 miles I had the bike.  I rue the day when I will have to do this job on the twin F650GS. I think I could almost do the job blind on the R65 if someone handed me the right thickness feelers. Ok, Ok..maybe not.

[msbuck]

Aïda, I do sympathize with you and I have been in the same "unknown" territory with the F650GS. Shims??? What??? We sure are spoiled with our boxers. The F650GS single I have sold now..the one I had in Raleigh back in '06, is in the shop getting its valves checked for the new owner. I never did check them myself in the 21,000 miles I had the bike.  I rue the day when I will have to do this job on the twin F650GS. I think I could almost do the job blind on the R65 if someone handed me the right thickness feelers. Ok, Ok..maybe not.

Sue, you sold your single and now have one fo the NEW twin F650GSs     Maybe you've talked about this elsewhere, but I've been away for awhile...can't seem to keep up with the forum these days.  I can't wait till we get the twins in the states and check them out.  I hear maybe July...

Still have the Laverda on the bench with it torn apart, waiting on parts at this point.  We called up a friend with much experience with this type of adjustment and what a difference it makes when you know what you're doing!!  It wasn't really as bad as I expected (so far).  Now I just have to find those shims.... not like finding parts for the Beemer...

You don't even want to hear what it took to replace the fuel filter!!!!