[How To] Checking the valves

Usually after the first check/adjust, the clearance stays pretty much unchanged. The last two times I checked, all the valves were still within the +/- range of OK.

Using high RPM continually greatly accelerates wear on the valve stem and the tip of rocker arm adjuster but I doubt if anyone in this crowd is that type of rider. :smile:

DirtFlier said:

Using high RPM continually greatly accelerates wear on the valve stem and the tip of rocker arm adjuster but I doubt if anyone in this crowd is that type of rider.

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What would you consider high rpm? When I'm cruising at 80, I'm turning a bit over 5650rpm which is 2/3 of the way to red line.

Sun Honda's service manager and I talked about longer valve inspection intervals when I picked the bike up last Thursday. He thought I'd be safe to take the interval out to 12,000 miles. I'm guessing that it could go to 16,000.

My maintenance issues over the 97,000 I've got so far have consisted of at least 3 rebuild and/or replacements of the pannier latches; a water pump at about 50K; fork seals at about 50K; a cracked muffler at about 60K; the final drive at 80K; and some more final drive work at 94K; and the shock at 96.5K.

5650 is hardly what I'd call high RPM. If you regularly ran it up through the gears at or very near redline, I'd consider that to be not a good thing. You don't have to worry.

I would feel comfortable with 12k after two checks that didn't show anything amazing. My Honda CRV was required to have its first check at 105,000 miles "or if noisy" and it spins 2800 rpm at 60 mph. Some earlier CRVs had problems with valve recession but I don't think that is an issue with the NT.

If you think of the total turns of the engine in 12,000 miles of highway riding vs. the total turns of say 6,000 miles of city/urban riding, with its cold starts, stoplights, and lower gear accelleration and deceleration, I think the 12k of mostly top gear highway riding I do is easier on the engine anyway.

Phil Tarman said:

What would you consider high rpm? When I'm cruising at 80, I'm turning a bit over 5650rpm which is 2/3 of the way to red line.

Sun Honda's service manager and I talked about longer valve inspection intervals when I picked the bike up last Thursday. He thought I'd be safe to take the interval out to 12,000 miles. I'm guessing that it could go to 16,000.

My maintenance issues over the 97,000 I've got so far have consisted of at least 3 rebuild and/or replacements of the pannier latches; a water pump at about 50K; fork seals at about 50K; a cracked muffler at about 60K; the final drive at 80K; and some more final drive work at 94K; and the shock at 96.5K.

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Yes, I agree that 12k at highway speeds is much easier on the engine than half that distance in city driving. Also easier on the brakes, clutch, etc.

I've decided on a 16K valve check interval. I think that my bike had around 35K on it when I started my trip to Alaska. That was a 15K ride. I checked the valves before and after and they were all within spec. I touched up a couple of them to move them to the center of spec. I'm satisfied that the bike can go 16K between checks.

+1 to what Bob says! Why didn't we ever hear about JIS screwdrivers before the last year or two? They make an amazing difference in working on Japanese motorcycles.

I only became acquainted with JIS drivers about 6 years ago. The right tool for the right fastener makes all the difference!

Phil Tarman said:

+1 to what Bob says! Why didn't we ever hear about JIS screwdrivers before the last year or two? They make an amazing difference in working on Japanese motorcycles.

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Phil Tarman said:

Why didn't we ever hear about JIS screwdrivers before the last year or two?

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Remember those impact drivers from back in the day? You couldn't get those damned screws out til you took your little impact driver to the screw and cracked it with a hammer. Out it came with no damage.

bicyclist said:

Remember those impact drivers from back in the day? You couldn't get those damned screws out til you took your little impact driver to the screw and cracked it with a hammer. Out it came with no damage.

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Back in the day? I still do that!

Even though I have JIS screwdrivers as well.

elizilla said:

I still do that!

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I still have mine.

I still have my impact driver in it's little metal case but now, it's only used rarely. In the Days of Your, both side covers on a Japanese motorcycle were secured with phillips head screws so it got a lot of work. I was happy when Honda switched to the 8 mm hex head bolts for the engine covers!

I bought an expensive JIS magnetic tip screwdriver a few years ago and using it made me wonder why I didn't buy one sooner! There are a few screw locations on the NT where the magnetic tip has saved me a lot of grief; such as the two phillips screws that secure the plastic cover just aft of the seat.

I checked the valve clearances on Debbie's 2010 NT last weekend. She has around 27k miles and going by how everything under the tank looked undisturbed, I'd say it was the first time the cylinder head covers had been removed. All the clearances were OK.

I was trying to forget those days but still have my impact screwdriver. I can't tell you the last decade I used it, though.......

bicyclist said:

Remember those impact drivers from back in the day? You couldn't get those damned screws out til you took your little impact driver to the screw and cracked it with a hammer. Out it came with no damage.

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[...and am down to the throttle body bands. That [expletive] front one is gonna be tough. I can't even see it, can just wedge a fat finger enough to feel it...]

Bob,

If you go to "DirtFlier's Album," you'll see my solution from long ago. After my first valve clearance check in early 2010, I swore to fix it somehow.

The square nut on the Honda clamp is 5 mm and you can buy 5 mm all-thread rod at a well-stocked True Value hardware store which is what I used to make the extra-long screw with spacer. I epoxy'd an 8 mm nut on the end of that all-thread rod to make it into an extra-long screw.

If you make the new screw 25 mm longer, it works nicely because you can see the head from above.

raybob said:

Ugh.

Decided to attempt a valve adjustment and am down to the throttle body bands. That [expletive] front one is gonna be tough. I can't even see it, can just wedge a fat finger enough to feel it.

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Back in July 2013 when I did my valve adjustment, I put up a post with a couple of suggestions. One was that I was able to get a screwdriver on the right side throttle body clamp from the side of the bike. I took off the coolant expansion tank bolt so I could move the tank out of the way a bit. Needed a longish screwdriver with a narrow handle, but it made the job easier. Good luck!

raybob said:

Ugh.

Decided to attempt a valve adjustment and am down to the throttle body bands. That [expletive] front one is gonna be tough. I can't even see it, can just wedge a fat finger enough to feel it.

"Y'all are better mechanics than I am to have done this, that is for sure", says Bob who may very well dream of a DR650 tonight.

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The first post in the thread shows the tool I used to reach that screw. I struggled with that one too! Once you get the plastic off, and you get that screw off, you have pretty much won at this project.

I like Tosh's mod, and if I were doing an NT valve adjust again, I'd do that myself.

raybob said:

That was the trick! Now have the throttle bodies ziptied out of the way. Onward!

View attachment 10189

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Hope all is back together and you're on the road. But I wish I had mentioned two other points. I still think its easier to adjust the rear cyl valves before taking the throttle bodies off. Then you can replace the rear cyl valve cover, pop the throttle body assembly off, and just gently set it back on the rear cyl valve cover. And one other thing I hope to try on my next adjustment. I found it difficult to weasel the front valve cover off, because a frame member sits right above it reducing clearance. But I think if you turn the engine so the front cyl is on exhaust stroke, the exhaust valve rockers will be compressed down, and this might create more clearance to get the valve cover off.

I always do the rear cylinder first, with throttle bodies still installed. And in ref to the front cover, I've never tried turning the crank so the front cylinder exhaust rockers would be down but it's certainly worth a try.

I've always looked at reinstallation of the front cylinder head to be a Chinese Puzzle where an arcane sequence of twists and turns are required!

Well after reading all of that I will continue to pay the dealer and take it in about every 20K to have the work done. It does not sound like a do it yourself parking lot adventure.

NoVa Chris said:

And one other thing I hope to try on my next adjustment. I found it difficult to weasel the front valve cover off, because a frame member sits right above it reducing clearance. But I think if you turn the engine so the front cyl is on exhaust stroke, the exhaust valve rockers will be compressed down, and this might create more clearance to get the valve cover off.

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I can confirm this works. I turned engine about 3/4 rotation past compression, guessing that would be the middle of the exhaust stroke, and the front cover came off without any struggle at all. After completing the adjustment, I reset the engine so the front exhaust valves were compressed, and again it was easy to replace the cover. I'd guess I had half an inch of clearance. Virtually eliminates the possibility of getting the gasket out of place.

When the exhaust valves are closed so the rocker/adjusters are "up", the adjusters interfere with the forward lip of the cover, making removal a "Chinese puzzle" as DirtFlier describes it.