Cam Chain Tensioner

[MrSinator]

I haven't been able to find any posts, even on the UK forums regarding this issue: Around 1k miles ago I noticed a slight ticking noise from the front cylinder. I just went to my usual mechanic for some service and asked him to have a listen. He and another mechanic both said that it sounded like the cam chain. The noise goes away when you blip the throttle or are under load, it only does it at idle. They informed me that the bike has automatic chain tensioners and that at this point it shouldn't be anything to worry about unless it gets louder or more frequent. He believes that it may just be things stretching out a bit now that the bike is close to the 8k mileage mark. This mechanic has always done good work for me so I trust his judgement. I was wondering if anyone else had noticed this on their NT. The bike runs the same as when I first got it, no drop in RPM's at idle or load, no change in temperature, no change in fuel mileage. I bought the bike used with about 700 miles on it and the warranty had fallen off by the time I bought it so I'm hesitant to take it in to the dealer if it's not something that actually needs repairs. Again, I trust my mechanic 100% but every time I hear that noise it just bothers me.

 

[Phil Tarman]

I don't know about the NT, but this was a common issue on '86-'06 Kawasaki Concours. There was even a company who made a replacement cam chain tensioner. But most of us figured out that just a the noise got loud enough to make us think the engine was getting ready to grenade itself, it was only a day or two away from taking up the next click on the tensioner. I don't know if the NT's tensioner has a ratchet like the Connie's did or not, but I think I'd trust your mechanic. Variations of this engine have been in lots of bikes for lots of years. I think if cam chain troubles were common, your mechanic would have known it and taken action.

 

[Rocky]

Yep, I have a ticking noise I thought was a valve out of adjustment but when I did my valve check all where in tolerances. Not to say just cause they are in tolerances they may not tick a little. I hear my tick at around 3 to 5 grand when under load, but smooths out at higher RPMs. It is very minor but I am very attentive to motor and operation sounds as changes can mean problems. I am still convinced my noise is just valve tick and normal. My old GPz at idle has a nice cam chian tick, or more rattle, probably due to age. I have a manual cam tensioner I adjust once a year and because the chain is worn it can make some noise at idle because going that slow it is not under a lot of tension. Nature of both beasts I think.

 

[elizilla]

The NT's fairing reflects noises in such a way that things can sound really odd when you are sitting on the bike with your helmet on, and you'd never notice them if you were standing next to the bike. Is this just one of those noises? If so, earplugs will cure it.

 

[Rocky]

I've read your post 2x but did I miss talk of checking the valves? I'm sure your mechanic is good, and more experienced than me, but bikes that I've had in the past with bad/weak tensioners made a "jingly" sound. Valves make a ticking sound.

Good luck.

Bobagain is correct, a ticking is normally valves that could be getting out of adjustment, or getting close. My GPz makes a more of a clatter noise at idle, clac, clac, clac,

 

[MrSinator]

I had the valves done at break-in and haven't had them checked since. I plan on having them checked in the near future when money allows because I'm just not comfortable doing that myself, nor do I have the facilites to work on something like that as my bike is parked in an apartment complex parking lot where i can barely get a parking space to myself. My Suzuki Boulevard got out of specs on the valves once and it smoked at startup, idled rough, sluggish acceleration, etc. My NT runs like the day I bought it, but this ticking noise is just driving me crazy as it's a fairly new sound. I know my Boulevard started making all sorts of new noises in the 8k to 10k mile range as everything was really settling in. I just heard back from a very good friend of mine that actually works in the shop at the dealership where I bought my NT. He said "RIDE THE HELL OUT OF IT, IT'S A HONDA." As much as I want to take their advice, I haven't had a bike make this sound before, it's just nagging at me.
A few more details: You can hear the sound standing anywhere around the bike but it only starts after the bike hits around normal operating temperature. Starts up and idles just fine. The sound can also be heard while cruising at a consistent speed but not under load. The sound is not quite as loud as the pulsing in the airbox but is an obvious noise. It started about 1,000 miles ago after an oil change. Switched out of the dealer's Bel-Ray oil to a synthetic blend 10w-30 that my mechanic recommends. The noise is not a rhythmic sound, only intermittent, but occurs enough to get your attention. I'm wondering if it may have something to do with the oil too. I did find on one forum http://dn01.org/cgi-bin/topic_show.pl?tid=704 some disturbing pictures of a broken chain tensioner on a DN-01 model. Hoping this isn't a problem with the NT's. I signed up on the UK forums and haven't been able to find anything. Part of what worries me is the the NT is a new bike to the US. Few dealers or mechanics have even had them in the shop. My mechanic has worked on 1 other NT but he runs a service center, not a dealership and has a good knowledge of all bikes. Maybe I'm just getting worked up over nothing.

 

[DirtFlier]

Yes, you're getting worked up over nothing.

 

[elizilla]

We need the car talk guys to persuade you to imitate the noise you are hearing. That would be fun.

 

[Bear]

Katherine,
You are so right! The only way one could tame the various and sundry noises emminating from the Tupperware is to spray some sound deadening foam into the fairing. My 66 Cobra had an aluminum body which created some remarkable echoes. The sound levels in that beast exceeded 95 db. Even though the car had a nicely tuned high performance engine, it sounded like a thrashing machine in the cockpit. The Honda is quieter but does make some strange noises. I don't really worry--that's why God made warrantees.

 

[MrSinator]

Based on my past experience with bikes, this one doesn't feel as though I should even bother with the 8k valve adjustment. I'll probably go ahead with it just to make sure. I had my Boulevard's adjusted at break-in and they didn't work their way out of spec to the point that it affected performance until about 36k. It just struck me as strange that this cam chain noise seemed to just start rather suddenly. I ride year-round and it does seem to have picked up slightly with the warmer weather and slightly higher engine temperatures but absolutely no change in performance so I haven't really worried about it. I was afraid that maybe when I put the K&N filter in then I may not have fastened something down right and that might be rattling but when my mechanic and my friend at the Honda dealership both suggested cam chain it kind of had me worried as I have no experience with those components. I was afraid my warranty was out too but I did find out that it's good until Sept. of this year so if there are any problems, at least that will cover it. Probably wouldn't be a bad idea at the valve adjustment service for them to look at it since they'll have the valve covers off anyways.

 

[dnktng]

It started about 1,000 miles ago after an oil change. Switched out of the dealer's Bel-Ray oil to a synthetic blend 10w-30 that my mechanic recommends.

A cheap fix may be to change back to the original oil. It doesn't look like the tensioner is hydraulic, but if your noise started after an oil change & and an oil change does no harm, why not do it.

Looked at the dn01 pics. ThaYou probably already know that the DN01 and NT700 have the same tensioner.

Since you were planning to have the valve checked soon, and since a mechanic should be able to see the cam chain tensioner while performing the valve check, it may be in your best interest to get the valves checked sooner than later.

Did you listen to this guy's video with OK audio of his DN01 bad cam chain tensioner. Does your sound like this?

 

[MrSinator]

Mine is more intermittent and goes away when you blip the throttle or accelerate, only makes noise at idle and cruising speed. His sounds pretty constant. Mechanic said that's why he believed that mine may just be making a normal noise. Seems like it pulls the slack out when you put it under load. Also, mine is more of a ticking noise, his sounds like it's slapping around quite a bit. Mine actually sounds a little more like this. Although this isn't a Honda, this is very close to the sound it's making http://www.youtube.com/watch?v=QaJi1tMyNhY

 

[dnktng]

I was afraid my warranty was out too but I did find out that it's good until Sept. of this year

Use that warranty. Have Honda listen to it. Show them the DN-01 failures from your link, and explain that the motorcyles use the same cam chain tensioner. It's a legitimate concern.

 

[Lorien]

OK you made me look. In the Honda shop service manual which I have there appears to be no mention of any adjustment to the cam chain tensioner. Certainly it is not in the routine maintenance. If it is out of the wear limits it is simply replaced by my reading in Section 9-14 or thereabouts. This is a fairly large device compared to others I have seen over the years and you would have to get a fair way into the motor to pull one out so I hope it is not a problem. Considering that no mention of adjustment that I can find is made I suspect a long life is expected. The suggestion of going back to the oil you wear using prior to the sound beginning is a valid one and easy enough. This I would do. After that valve adjustment could be a likely candidate though the forum is full of examples of valves being only slightly out of adjustment with long use and I don't think anyone has burned a valve yet. That being said I do believe that something is being underlubricated sort of. I have had no small number of bikes that will do exactly what you describe on cold starts and then it goes away. I have even suspected that I hear exactly what you are describing on occasion with my NT. It happens around 50mph and around 3500 rpm if I leave it there for a extended period of time. Since this is not a speed or rpm I am at for extended periods it seems harmless enough. I am 20 k in it has not done anything drastic so I will watch and listen.

 

[Rmcapozzi]

I think you're running down a road based on a "gut" feeling from a mechanic that has very little experience with this motor. If it is a "ticking" noise, any number of things could make that noise. Even fuel injectors can "tick" quite loudly. Some valve trains are just plain noisey. Sometimes they start out quite and turn noisey but that doesn't indicate necessarily a problem. Even bikes of the same model will sound slightly different. A "ticking" noise with no performance degradation wouldn't cause me any concern. I would continue to follow Honda's maintenance schedule and not worry about it unless it becomes an excessively loud sound and the motor's performance changes.

 

[DirtFlier]

It's not easy to see the cam chain tensioner unless you remove the cam and lay the chain to one side of that well - none of this is done during a routine valve adjustment.

 

[elizilla]

Also, Oak Ridge, TN - you're right next door to motorcycle mecca, sheesh. Half the NTs in the eastern USA are probably going to pass within an hour of your house, this summer. Post up to this forum and find some lunch dates. Compare sounds!

 

[dnktng]

In your DN01 reference the mechanic was able to inspect the tensioner with a mirror and see the spring tab that was broken, but it sounded like that was not until the head was off....major work.
Also, in the DN01 thread the one owner was conclusively able to pinpoint the problem with a $3 stethoscope. Here it is:

One thing that finally convinced me to go in ... a stethoscope (these cost $3 at Harbor Freight). A noise, a clatter, very generalized. Listened to various points on the engine...still did not seem conclusive. Yesterday morning went back at it with the stethoscope in hand, this time with a more specific objective in mind. If you look at the right side of rear cylinder (just behind the exhaust pipe protecter) you will see two 10MM hex bolts on the cylinder head. These two bolts have copper washers and hold in the cam chain tensioner. Once I placed the probe on the top bolt with the engine running...BINGO, that bolt was transmitting the sound with an amplitude that was unmistakable. On the front cylinder the cam chain tensioner bolts are on the left side (and more accessible).​

Good news: to measure the tolerance for the cam chain tensioner only requires the valve cover off, same as adjust valves. You should at least have this measured when you do your next valve adjust. I'll measure mine during the next valve adjust since it requires no further disassembly. Bad news: It looks like at a minumum that the cam needs removed to remove the cam chain tensioner if needed.

Really good threads on DN01 forum linked above. Lots of pics and video. These are recent failures (last fall) and one person explains that many are being reported. Haven't heard of cam chain tensioner failures on NT700, but it is the identical part, with exact part number.

Honestly the noise on Kawasaki link above that you says sounds like your NT700 did not sound odd to me. The NT700 is clicky, noisy engine (and fuel injectors as mentioned), and noise does strange things in all that plastic and a helmet. Hopefully this is your noise. What would concern me is if you could pin the noise down to one cylinder. Also, noise that dissappears as you accelerate, but is present at no load could be abnormal and a cam chain tensioner issue.

If it was me.
1. Post question on a forum and gather ideas. (Hey, you're a step ahead of me)
2. Change oil to previous oil that wasn't noisy. Try it out. Different oils can change engine sounds.
3. Noise still there, buy a cheap stethoscope and try to isolate noise. If one cylinders cam chain tensioner bolts making all the noise would be a bad thing. General noise, that's the nature of the engine.
4. Its under warranty, have Honda mechanic listen to it. Even though mine isn't under warranty, if a noise concerned me enough to ask the question, I'd take it to Honda just to listen. And keep that paperwork.
5. Check tensioner wear limit during next valve adjust. Do this when you normal would do it, no need to do it tomorrow or anything drastic unless it gets worse.

One final disclaimer. "I'm not a mechanic, but I play one on the internet"

 

[dnktng]

NT700 & DN01 Cam Chain Tensioner is spring tension only. No hydraulics assist or ratcheting adjustment.
Here is group of pictures of a good and bad Cam Chain Tensioner from one of DN01 owners. Great pictures with descriptions.

 

[dnktng]

I read that whole thread on the DN-1 forum. Sounds disconcerting at the least.

Yes, it is. The good news is if the cam chain tensioner spring tab wears thru, the engine noise will scream, "I'M NOT NORMAL." The noise is not going to sneak up on you over several thousand miles. So there isn't much sense in listening for it, it wont be there until it pops.

Looking at how the tensioner works, I now think that the wear measurement described in the service manual would not help find the spring tab starting to wear out before it wears thru. If it is going to wear thru there seems to be no early warning, it's just going to pop, and the engine noise immediately after.