When To Do Valve Clearance Check.

[WTaute]

Hi everyone

This is something I would like to share and give my opinion on this topic...I've build quite a few race engines and I don't understand why people are so concerned about valve clearance check...If you look at the engine head you will notice that the valves will ,with time, pull into the valve seat, which is normal, as this is happening the valve actually move further away from the piston when it is opening because of the wear, so no it will not cause valve to piston damage, but the problem is that it will become harder to start as the valves are partially open and you can not build pressure, this also occur mostly when engine is cold, so my opinion is when you start getting hard start issue then you do a valve clearance check...one thing I would highly recommend ,never go below your minimum shim thickness, you stand a very good chance to break the valve and cause mayor damage to the engine...any input to my view are welcome.

 

[brooke]

I was always under the impression that if the clearance got to less than zero the problem during normal hot operation became burnt valves ?

 

[WTaute]

Yes that is also correct, but the hard start occurs first...

 

[James.gower]

Why wait until it’s hard to start? In my day we did recommended valve adjustments every 3k to 6k miles on Hondas. The latter mileage were more for DOHC shim on bucket types. These were not race bikes, but street machines. Nowadays, Honda recommends valve adjustments only if the valve train is noisy. Seems stupid to me.

 

[WTaute]

Why wait until it’s hard to start? In my day we did recommended valve adjustments every 3k to 6k miles on Hondas. The latter mileage were more for DOHC shim on bucket types. These were not race bikes, but street machines. Nowadays, Honda recommends valve adjustments only if the valve train is noisy. Seems stupid to me.

I hear what you say, but I've seen numerous bikes doing 80000km without any valve shim change, so all I am saying is, don't scratch where it doesn't itch....

 

[sixpac]

I agree with the idea of just checking it every year, as getting at the valves on the T120 looks easy
I had a Honda ST1300 , 3 shims were replaced at 28,000 k , and I checked the clearances every year and at 220,000 k all the valve clearances were with in spec , I ran Rotela T6 0/40

 

[brooke]

I sold Honda cars in the 70’s and 80’s . Honda wanted the valves adjusted a couple of times a year and the customers were not happy with the expensive economy . Apparently other dealers were doing it every year or two and keeping the complaint level acceptable . My 92 Camry had the bucket and shim set up and never had an adjustment , dealer advice , sold it at 378,000 kms , all good .