Valve Clearance and Shim Changing

[MotoMike]

I ride a 2007 FJR 1300A. I have just completed the valve clearance checks at 84,000 kms. Five of the clearances on the intake side are just at the bottom of the spec (0.15mm). Four of the clearances on the exhaust side are also just at the bottom of the spec (0.18mm). I do not plan to lift the camshafts completeIy off the top of the engine in order to change the offending shims. I have zip-tied the cam chain to the camshaft sprockets and to the crankshaft sprocket. I plan to release the tension on the cam chain tensioner.

Question 1: will I need to completely remove the tensioner from it's mounting point on the engine or will just releasing the tension on the chain be sufficient to allow me to move the cams enough to be able to access the buckets and shims?

Question 2: Can anyone recommend a good source of shims. I am in Moncton, NB, Canada.

 

[RossKean]

If they are all still in spec, I wouldn't touch them until the next check, unless you are planning a lot of riding in the upcoming season and won't have the luxury of a long maintenance season (aka winter in Atlantic Canada) to do the work. Spec is spec and Yamaha expects that they will not wear too much before the next scheduled check to cause any damage or seriously harm performance. There is a significant tolerance and the specifications are conservative.

You do not need to remove the tensioner. It has to be retracted and kept from releasing while you are working on it. I turn it with a suitable long shaft screwdriver through the hole in the frame and clamp a small vice-grip on the shaft to weight it down and keep it from turning back under the spring tension. A piece of tape to hold stuff in place so the blade doesn't slip out of the slot.

Zip-tie your cam chain to the cam sprockets and take similar precautions to ensure that the chain doesn't slip on the crank on the bottom end. Mark the cam sprockets at TDC on the INSIDE where the marks are easier to see than the factory marks on the outside of the sprockets. You'll thank me later.

These are a common motorcycle engine shim (9.48mm dia.). Most motorcycle shops will have them in stock - at least in their service department. I would certainly check with Motoplex and others. They might even swap shims with you (more likely a small independent for that). I swap shims around so I don't need as many. I have been known to sand shims down using wet carbide paper on a piece of glass. 240 grit, followed by 400 and frequent measurements using a digital caliper or micrometer. Shims are NOT surface hardened and I can do one in 5-10 minutes.

Use the Valve Check Excel spreadsheet for calculations and record keeping.

If you decide to make changes, set all clearances to 70% of the maximum and you may never need to do them again.

 

[MotoMike]

RossKean,
I thank you for your sage advice: "spec is spec". I am choosing to leave well enough alone and re-check the clearances at 126,000 kms.

 

[RossKean]

RossKean,
I thank you for your sage advice: "spec is spec". I am choosing to leave well enough alone and re-check the clearances at 126,000 kms.

One man's opinion, but this is nothing different from what Yamaha would recommend. These clearances do not change quickly and I'm sure you will be fine.
On my 2007, the intakes were all close to minimum on the first check. I didn't end out making changes until I was well over 150,000 km. One more adjustment needed while I owned the bike, but that was at over 250,000 km.