Nc750x Valve Check

[FurstyFerret 146]

2 hours ago, Jamesc said:

Wild guess : low battery 

 

1 hour ago, Whysub said:

Cetainly.

 

I live in SE Spain, so I rode the 2½ hours to Almeria and got the  11.30 am ferry from there to Nador. Arrived in Nador just as it got dark, so stayed there. Watch out here, as loads of cars and motorbikes don't seem to have head or tail lights.

 

From Nador rode to Fez, none too taxing a ride as an introduction, and stayed overnight.

 

From Fez, set off south for the Sahara at Mergouza. Encountered rain, snow and Barbary apes over the Atlas mountains, before hitting a sand storm about 20kms from Mergouza. 

 

Mergouza has plenty of traditional Riads to stay in. Spent a couple of days there, doing all the desert-y things (quad bikes, walking the town and the dunes, etc, etc.). Also rode down to the Algerian border. At 9.3 million km², I still can't grasp how big the Sahara is.

 

From there to Ait Ben Haddou (many classic films have been made there), on to Tafraute, then Sidi Bibi, onto Ouzoud (highest waterfalls in North Africa), onto Meknes,  and then up to Chefchaouen (the blue city) on the north coast, then I rode backalong the coast road to Nador for the ferry.

 

A great round trip that avoids the bigger cities (seen one Moroccan market, seen them all in my eyes).

 

Morocco is a great place to ride around. Empty roads for miles, come into a small town  and its always hectic with cars, trikes and little red taxis until you get out on the other side of the town.

 

Petrol is easy to find, as are cheap hotels/apartments, and food, such as proper tagines which are very healthy. You can buy alcohol from some hotels and also in bigger towns from Carrefore supermarkets in their seperate alcohol sections.

 

The people are friedly, but in the tourist areas, where there are Berbers (if they are in fact Berbers) can hassel you to buy things from them. A firm "No", but not being rude to them worked ok for me. Be hesitant and they will keep on at you from what I saw.

 

I'm going back later this year, but using two wings, not two wheels. I really need a trip away from the bike in 2025.

 

 

That was awesome 👌 thanks for taking the time to detail, definitely got me thinking. Appreciated 🙏 

[Prof69 41]

Doing the valve check on the NC750 is just like my classic Hondas back in the 1960s and 1970s, with an adjusting screw and a lock nut. The only complication is needing to remove the radiator to get at the valve cover.  Any motorcyclist should be able to do the job after watching some YouTube videos.  Here's a good one: https://www.youtube.com/watch?v=UA0X6bmT3rE

 

Just take your time and remember how much money you're not paying the dealer for a simple, routine job.

[Prof69 41]

My 1995 CB750 Universal Japanese Motorcycle has hydraulic lifters, and the valves NEVER need adjustment. I wish the engineers would consider going back to self-adjusting valves.

[Dan German 2,226]

10 hours ago, Prof69 said:

My 1995 CB750 Universal Japanese Motorcycle has hydraulic lifters, and the valves NEVER need adjustment. I wish the engineers would consider going back to self-adjusting valves.

Those 750s kind of hit a sweet spot for using hydraulic valves. They weren’t “high performance” enough for the risk of lifters pumping up at high rpm to be a huge risk, and they weren’t basic enough for the added complexity and manufacturing cost to be a downside. You wouldn’t want to bother with hydraulic lifters on something like a Himalayan, and it wouldn’t be a great idea on a bike that revs over 10,000 rpm. 

 

Clearly, if what I said above has any truth to it, the NC700/750 should have had hydraulic lifters from day one. 

[Tegraman 3,508]

On 13/04/2025 at 05:11, Prof69 said:

Doing the valve check on the NC750 is just like my classic Hondas back in the 1960s and 1970s, with an adjusting screw and a lock nut. The only complication is needing to remove the radiator to get at the valve cover.  Any motorcyclist should be able to do the job after watching some YouTube videos.  Here's a good one: https://www.youtube.com/watch?v=UA0X6bmT3rE

 

Just take your time and remember how much money you're not paying the dealer for a simple, routine job.

Indeed, it is an easy job. Just don’t murder the locknuts when re-tightening. "хватит хватит” as the Russians say.

[Andy m 26,943]

The Enfield 500 UCE has hydraulic tappets. I suspect an error where the "Lifetime Revenue" accountant failed to realise what Engineering were proposing. I doubt they sold one extra bike based on the extra cost, yet certainly missed a few million in workshop revenue and the opportunity to get the owners to trade up.

 

Hands up everyone who walked out of a showroom because the design has silly race features? Then hands up who has had to sit through someone going on about how ally the demonic valves are on his Ducati because they don't bounce at 45 mph on the local ring road. Now you see why so many bikes have bucket and shim insanity (or worse).

 

Andy

Edited April 15 by Andy m

[Tegraman 3,508]

I have an idea, let’s dispense with all the malarky of a gear train, or even more complex and noisy, a chain drive, and instead make the tappets go up and down simply by shoving them with a lightweight steel tube itself shoved by a follower on a cam on a shaft geared directly to the engine crankshaft. We could call the tubes “pushrods” and expect a million mile life out of them.

 

Ah, no, can’t do that, the tubes wouldn’t work properly at a billion rpm, and more to the point, we couldn’t claim our system was  overhead cam, which everyone knows must be better for our race road bike because of its cool name.

[Slowboy 24,726]

1 minute ago, Tegraman said:

I have an idea, let’s dispense with all the malarky of a gear train, or even more complex and noisy, a chain drive, and instead make the tappets go up and down simply by shoving them with a lightweight steel tube itself shoved by a follower on a cam on a shaft geared directly to the engine crankshaft. We could call the tubes “pushrods” and expect a million mile life out of them.

 

Ah, no, can’t do that, the tubes wouldn’t work properly at a billion rpm, and more to the point, we couldn’t claim our system was  overhead cam, which everyone knows must be better for our race road bike because of its cool name.

Too much unsprung weight in the valve train I thought. OHC is more efficient due to weight saving, if I recall correctly. I also is a more rigid and therefore more accurate system. At least one less wear point as well, if done simply.

 

We could go for side valves, way more compact, but the unburned hydrocarbons from one of them might be enough to run a moped as well….😂😂

[Andy m 26,943]

I'll have sleeve valves please. Slicker than a teflon coated Dean Martin impersonator dipped in chip fat.

 

Please wait until I buy shares in a gear manufacturer though 

 

 

Andy

[Tegraman 3,508]

7 minutes ago, Slowboy said:

Too much unsprung weight in the valve train I thought. OHC is more efficient due to weight saving, if I recall correctly. I also is a more rigid and therefore more accurate system. At least one less wear point as well, if done simply.

Chasing the last 1% could be important if we really need it. The % is debatable of course, but then so is “really need”. A parts count would tell some of the story, since even a shaft drive to an OHC needs additional stuff. 

 

The simplicity=reliability debate has credibility, and of course there are tradeoffs in efficiency, but in the world of not-rich DIY bikers who rarely if ever use more than 90% of their bike’s power, is slightly more fuel efficiency worth the candle of more complex machinery?

 

Side valves are another matter, their parts count is similar to OHVs but are inferior in combustion chamber dynamics.

[Prof69 41]

Ducati, with its desmodromic system, reigns king for the most difficult valve adjustments.  But a close second place is anything with a shim-under-bucket system.  I did the 18K valve check on my Honda ST1300, and ended up with a bunch of bent feeler gauges and a lot of time used up. Luckily, the shim-under-bucket valves don't vary much, and mine were all within spec. If you have to "adjust" the valves, it involves removing the camshaft, honing the shim the computed fraction of a mm, and reassembling everything, making sure to get the camshaft timing right. Plan on spending all day. They charge an arm and a leg to do it at the dealer.

[jeremyr62 3,407]

7 hours ago, Prof69 said:

Ducati, with its desmodromic system, reigns king for the most difficult valve adjustments.  But a close second place is anything with a shim-under-bucket system.  I did the 18K valve check on my Honda ST1300, and ended up with a bunch of bent feeler gauges and a lot of time used up. Luckily, the shim-under-bucket valves don't vary much, and mine were all within spec. If you have to "adjust" the valves, it involves removing the camshaft, honing the shim the computed fraction of a mm, and reassembling everything, making sure to get the camshaft timing right. Plan on spending all day. They charge an arm and a leg to do it at the dealer.

Maybe in actually doing the adjustments, but the front cylinders on the VFR1200 are horrific to get to. I checked them but I will never ever do them again. Mine were all in spec so I was lucky. How you would go about  doing the intake shims if they actually needed adjusting would be a double nightmare as these are shimmed. The exhaust are locknut (Unicam engine). Either completely strip the bike above the engine or take the engine out. I won't be finding out that's for sure. I'd let the engine blow up before doing them again.

[Slowboy 24,726]

My Ducati 998S was an engine out job to do the shims (only three bolts from memory, but a load of electrical connectors😂.

 

My Ducati GT 1000 was relatively easy, with the engine in.

 

You always sweated (at least I did) the first time you fired it up after doing them….😱

[Tegraman 3,508]

2 hours ago, Slowboy said:

engine out job to do the shims

W. the holy F. How old were the designers, twelve?

 

I’ve said this before, but there ought to be someone on the board at the manufacturer’s palace who says, when presented with the design for a new engine, “Seriously? now go away, do it again, and don’t come back and re-present it until the maintenance procedures are sane.” 

 

Providing only tortuous access is just simply bad design, no excuse. 

 

Working on modern cars is like wallpapering the living room through the letterbox, but bikes should be different.

 

10 hours ago, Prof69 said:

They charge an arm and a leg to do it at the dealer.

Gosh, I wonder who that benefits, oh…..hang on……...

[Slowboy 24,726]

1 hour ago, Tegraman said:

W. the holy F. How old were the designers, twelve?

probably, you could do it engine in but it was too risky really, much easier once it was out.😂😂

Quote

 

I’ve said this before, but there ought to be someone on the board at the manufacturer’s palace who says, when presented with the design for a new engine, “Seriously? now go away, do it again, and don’t come back and re-present it until the maintenance procedures are sane.” 
 

Dead right. “Maintainability was a big part of our design processes.

Quote

Providing only tortuous access is just simply bad design, no excuse. 

True, unless there are real measurable advantages, which there usually aren’t.

 

Seriously, that’s why I like my Enfields, controversial maybe, but they’re so easy to maintain. My NC700X had far too many push clips and snap fits that made most jobs a b*gger to do. The NCS models are better in that regard, a bit.

Quote

Working on modern cars is like wallpapering the living room through the letterbox, but bikes should be different.

true, and there’s rarely a good excuse for it. My Super Cub is an order of magnitude more difficult to maintain compared to my old C90. It’s totally influenced by accounts not engineering. My BMW R50, 70 years old this year, is a lesson in simplicity, maintainability and fine engineering, if not in emissions and performance😂😂

 

Quote

Gosh, I wonder who that benefits, oh…..hang on……...

Indeed.

Edited April 18 by Slowboy

[Andy131 1,786]

I have always maintained that design engineers should spend at least two years on the spanners before they are let anywhere near a drawing board (CAD station these days).  Preferably the last year doing maitenance on-call so they can get to remove the giggling pin, while half asleep, frozen and wet through because it failed outside ... again

[Slowboy 24,726]

19 minutes ago, Andy131 said:

I have always maintained that design engineers should spend at least two years on the spanners before they are let anywhere near a drawing board (CAD station these days).  Preferably the last year doing maitenance on-call so they can get to remove the giggling pin, while half asleep, frozen and wet through because it failed outside ... again

Exactly what the best companies do. It's a big investment though.

[Dan German 2,226]

On 18/04/2025 at 01:05, Slowboy said:

My Ducati 998S was an engine out job to do the shims (only three bolts from memory,

I have no complaints about removing an engine for service. It’s much easier to work at a workbench than a lift or stand. Of course, that assumes that the engine is easy to remove. I once had a friend help me replace the clutch in my ‘78 Subaru. He was appalled that the engine had to come out, instead of just the transmission. It was shockingly easy, and we stayed standing for most of the job. And I often took air-cooled VW engines out to do valve adjustments. It wasn’t required, but sometimes better than lying on the ground (see: Winnipeg winters). 

 

On 18/04/2025 at 04:55, Slowboy said:

 My BMW R50, 70 years old this year, is a lesson in simplicity, maintainability and fine engineering, if not in emissions and performance😂😂

 

Indeed.

Total opposite of my above examples. I couldn’t stop giggling when I realized that rebuilding/modifying the top end/connecting rods of my R80G/S could be done, engine in, in a parking stall. I took a photo of my friend through the holes in the case just for a laugh (wish I still had it).