valve clearance gab inspection

[zaki-herz]

I have put, so far, 31k miles on my 2024 Honda NC750X and wonder if I need to check valves' gab-clearance?

The engine runs fine w/o any sign of any sort, and no issue at all.

a) so, do I still need to do the extensive work of checking on the gabs strictly based on milage?
b) is there any symptom that the gabs are out of spec?

 

[jbawden]

Gab clearance? Assume you mean valve lash. What does the service manual say about check intervals? Honda is generally really well sorted on those recommendations.

 

[ichabodnt650]

Honda NC750 manual recommends checking valve clearances (aka gaps, lash) every 16,000 miles / 25,000 km

The screw & lock nut variety you have tend to need adjusting more frequently than the shim under/over bucket variety, but thankfully they are easier to do . If they have never been checked in 31,000 miles then you should check it soon.

a) so, do I still need to do the extensive work of checking on the gabs strictly based on milage?
b) is there any symptom that the gabs are out of spec?

a) Yes
b) clacking sound, burnt exhaust valves

 

[ST Guy]

Never heard of gabs.

 

[zaki-herz]

Gab clearance? Assume you mean valve lash. What does the service manual say about check intervals? Honda is generally really well sorted on those recommendations.

service manual says check the valve lash every 20k miles.

 

[Blankpage]

Not something you can ignore

 

[John2023]

I have put, so far, 31k miles on my 2024 Honda NC750X and wonder if I need to check valves' gab-clearance?

The engine runs fine w/o any sign of any sort, and no issue at all.

Good idea to check it. Like you, my bike rode fine too but figured I check the valves as it was about 4k miles overdue. Sure enough, a couple of the shims needed to be replaced. I didn't want to pay the stealership $1500 so I did it myself. The task took longer because the cams had to come out in order the pull the under the bucket shims out to replace it. Wasn't bad overall as I took my time. The best part is I was able to exchange the out of specs shims for the correct ones at no charge.

Good luck!

 

[zaki-herz]

Thank You for all the feedback.
The dealership estimate for the valve adjustment + Spark Plugs replacement was close to $2k.
That gave me the incentives to take the matter in my own hands.
It was easier than what I envisioned; yet, I did run into some additional work:
- Remove the engine guard so I can remove the lower cowl that covers the oil filer
- Remove the fog light so I can remove the engine guard (that was not hard at all)
- Remove both sides of furring, all the plastic covers so I can reach the fan connector
- Could not disconnect the cooling fan connector, it was still hard to reach and did not know how is clipped together
- So, I ended up disconnecting the fan from the radiator, 3 bolts; that was not hard
- I put a thin minor bead of black sealer at the crank cover.
- I did not put any antsieze on the new spark plugs.
Surprisingly, after 31k miles, all the valves were, more or less, withing acceptable tolerances. Yet, I did make little adjustments.
The original spark plugs, seemed in reasonable condition after 31k miles. Please let me know what you think about the spark plug?
Laying on the floor is my only helper, he sometimes gives mewing comments if something was not going right.

 

[ScottRNelson]

Oh, you meant "gaps", not "gabs" - got it.

If you have too much clearance it can cause a bit more wear and some noise. With bigger clearance it will get worse as it wears.

If you don't have enough clearance the valves may not close completely and you can end up with burned valves, leading to a full valve job.

This reminds me that I'm overdue to check the valve clearance on my Honda.

 

[John2023]

Thank You for all the feedback.
The dealership estimate for the valve adjustment + Spark Plugs replacement was close to $2k.
That gave me the incentives to take the matter in my own hands.
It was easier than what I envisioned; yet, I did run into some additional work:

Good to hear and nice job!

Yeah agree, "$2k" for a valve clearance check is too high IMO. Different bike but the valve clearance check quote a dealership gave me for my bike was $1500. I did it myself as well and all the parts needed cost about $100. Since I had to replace a couple of out of spec shims, the cams had to come out so that took more time and labor than just the valve clearance check. Some math was needed as well after measuring the out of spec shims with a micrometer. The math determines the correct thickness of the new shims needed to replace the out of spec ones. The shim replacement process also requires another trip to the dealership to exchange the out of spec shims for the correct ones. Probable not needed but I also dabbed a little oil on certain areas of the cams, cylinder head, buckets and shims when installing the new shims and putting the cams back onto the cylinder head.