[CeeBeeArr]

I just had my first service done. No rattle/clatter/bb,s in a can noise at higher rpm prior to service. Now I ve got the rattle!! Bloody hell! At first service they checked valves, they were off spec...so they used 3 shims.... Now I've inherited the dreaded rattle. (my invoice shows a charge for 3 shims, so aim assuming they used 3)

Wow. That sure directly points at valve clearance as the source of the problem. I would find it very helpful to know if they removed and replaced the PAIR valve on the valve cover during the procedure. Just curious if disturbing the valve might cause grief.

Also am curious to know if the valves were tight before the adjustment.

I had to change the two exhaust shims on my bike because the clearance was about .003" tight. However, I didn't notice any change in the bike's sound after the adjustment.

I hope you keep us updated and thanks for the post.

 

[Kalboogie]

Wow. That sure directly points at valve clearance as the source of the problem. I would find it very helpful to know if they removed and replaced the PAIR valve on the valve cover during the procedure. Just curious if disturbing the valve might cause grief.

Also am curious to know if the valves were tight before the adjustment.

I had to change the two exhaust shims on my bike because the clearance was about .003" tight. However, I didn't notice any change in the bike's sound after the adjustment.

I hope you keep us updated and thanks for the post.

I ve got a good rapport with service manager, I ll ask to chat with the tech who worked on bike to get those answers.... Not having that rattle before and now having it...wow...really irritating to hear it... I feel for all those that had it at the start.

 

[Brian]

CeeBeeArr, I think unless they assembled something wrong it points to your pair valve theory. I did not look in the manual for the cbr, but I have a SH150i scooter, and Honda manual says to remove the P valve. I wonder why not just disconnect the hose, but there may be a clearance problem that requires removal.
Good job on the Pair valve.

 

[Redline]

Anyone any ideas on what would cause my rattle (marbles in a blender noise) when it's dry, but it being wet would stop it? What parts of the bike/engine are affected by wet weather?

 

[CeeBeeArr]

Anyone any ideas on what would cause my rattle (marbles in a blender noise) when it's dry, but it being wet would stop it? What parts of the bike/engine are affected by wet weather?

If my theory about the PAIR valve is correct then mufflers with less back pressure would probably make less of a rattle. However, you might not hear it because mufflers with less back pressure are usually louder.

According to this website (I just googled and found it so I don't know how accurate it is), the density of air changes with humidity.

Molecular Mass of Air

Wikipedia says the same thing and has references:

Humidity - Wikipedia, the free encyclopedia


Maybe it causes the ECM to run differently.

 

[Redline]

Thanks.

My 18000km service is due in about a month, I going to ask them to strip it as much as they can so I can ride it as naked as possible. In the name of experimentation.

 

[RazMan]

BABYFACE : EGR Block Off Plate [005-EH006]

Exhaust Gas Recirculation and The Pair valve are one and the same correct?
Above part looks interesting. Probably need a tube of liquid gasket if you wanted to make it a more permanent fix. (that's if it turned out to be the cause of the rattle)

I get the rattle at the same rpm band (5-6000rpm) I do have a IXLL system on it.

 

[sendler]

$50?

BABYFACE : EGR Block Off Plate [005-EH006]

Exhaust Gas Recirculation and The Pair valve are one and the same correct?
Above part looks interesting. Probably need a tube of liquid gasket if you wanted to make it a more permanent fix. (that's if it turned out to be the cause of the rattle)

I get the rattle at the same rpm band (5-6000rpm) I do have a IXLL system on it.

$50 bucks for that! I just found a new buisness to go into.

 

[Mr Redface]

I sure there are different rattles. But if you have the solid metal rattel(Ball bearings in glass sound) it is the values. My Bike has had this rattle since new. I just had my 600 mile tune-up and the dealer went thru the bike. They specilalize in Dirt bikes / Racing so 4 stroke singles they are very familar with. They adjusted the values and were able to minimize the rattle. But said this engine is going to never be complete silent in the valves as they did try. I would be very sure of your rattle before doing any mods.

 

[sendler]

Silent

My CBR250R is completely silent from engine rattles. Only a slight gear whine above 60mph.
.
.

I sure there are different rattles. But if you have the solid metal rattel(Ball bearings in glass sound) it is the values. My Bike has had this rattle since new. I just had my 600 mile tune-up and the dealer went thru the bike. They specilalize in Dirt bikes / Racing so 4 stroke singles they are very familar with. They adjusted the values and were able to minimize the rattle. But said this engine is going to never be complete silent in the valves as they did try. I would be very sure of your rattle before doing any mods.

 

[Redline]

My CBR250R is completely silent from engine rattles. Only a slight gear whine above 60mph.
.

Lucky you. Mine have almost disappeared the last few days (it's been very wet and damp and it always seems to affect it in a positive way ).

The difference in driving enjoyment is amazing. You actually here the sweet sound of the engine and get to enjoy driving in the mid range. With the rattle you seem to change gear as soon as it kicks in.

 

[Redline]

I sure there are different rattles. But if you have the solid metal rattel(Ball bearings in glass sound) it is the values. My Bike has had this rattle since new. I just had my 600 mile tune-up and the dealer went thru the bike. They specilalize in Dirt bikes / Racing so 4 stroke singles they are very familar with. They adjusted the values and were able to minimize the rattle. But said this engine is going to never be complete silent in the valves as they did try. I would be very sure of your rattle before doing any mods.

Mine is that sound. But it comes and goes. Usually there maybe 70% of the time.

Of late it's been there only about 40%.

When it's gone it sounds sweet, so don't think mine is that issue. But I try to never rule anything out until it's completely proven, and fixed.

 

[CeeBeeArr]

BABYFACE : EGR Block Off Plate [005-EH006]

Exhaust Gas Recirculation and The Pair valve are one and the same correct?
Above part looks interesting. Probably need a tube of liquid gasket if you wanted to make it a more permanent fix. (that's if it turned out to be the cause of the rattle)

I get the rattle at the same rpm band (5-6000rpm) I do have a IXLL system on it.

EGR and PAIR are different. The EGR valve mixes some of the exhaust gases into the fuel air mixture. The PAIR valve system adds some filtered air to the exhaust in front of the muffler to promote combustion of any unburnt fuel. The reason this is necessary is that most engines will suddenly jump rich if the throttle is suddenly closed. Something about the jump in intake vacuum. I say most engines because I think this engine cuts the injector off under those conditions and that is why the deceleration with the throttle closed is so noticible. No injector, no fuel to be unburnt.

You may notice that if when running, you carefully close the throttle to start decelerating, it slows down moderately. If you close it a bit more, it starts to slow down much faster. This, I believe is the clue that the injector is being cut off. It also explains some of the jerkiness in first at low rpms.

That is my theory at least but the only way to prove it is to monitor the injector signal and if I am going to do that I am going to do the same on the PAIR solenoid too.

I may try that. I may also record the same engine with and without the PAIR mod I mentioned to get some solid info.

 

[RazMan]

Thanks for the clarification CeeBeeArr. There are pair block off plates around though. Check other bike forums.

 

[Redline]

Update.

A nice woman in a toyota decided to smash up the front of my CBR last week. Had to get all new front and side farings and a new front headlight.

Picked the bike up yesterday and it hasn't sounded so smooth since I first rode it out of the dealer. All rattles gone except for that slight hum from 6/7000rpm that you'll get with a single.

I always suspected that it was something like the dash/headlight/front farings, and it seems to be. I've only put 50 or so km on it since yesterday, but what a joy to listen and feel the bike as it should be. Here's hoping it stays away.

Out of all the pieces removed I'd guess the headlight was likely to be the main culprit, if indeed it was something to do with all the pieces they changed.

Will report back, whether it develops again or not.

 

[CeeBeeArr]

That is great news. After driving my bike around for a week, I think I can say it is better but I cannot say it is cured. Notice that I said 'I think'.

Also, I discovered that even with the PAIR valve closed off as I described, it still manages to pull a bit of air through the system. When I completely blocked the source of air, all I could notice was a different exhaust odor. The mileage was the same at about 90-95 mpg on an imperial gallon (4.54 liters). I have unblocked the air source and might even set the PAIR valve back to where it was. Sorry to sound so confident previously; that is the problem with random errors. They always seem to bite back. Murphy's law may be in effect...

There is that occasional weird random rattle that occurs at 5000rpm or so and light throttle. Maybe I will figure out what it is. Maybe...

 

[TheMente]

My two cents for today:
started the engine this morning and rode it very slow while it was cold, for close_to_home commuting. Rattle was there.
Stopped for a while, with engine cold again I started more aggressive, keeping revs high and the rattle was gone.

I am wondering if the more gas in the mix gives similar effect than the moisture in the air that someone noticed.

 

[DV8]

I had my first service done today and was told that the rattle is in the engine and Honda is aware of the problem. Honda told my dealer it is the rocker arms.

 

[furious_blue]

Update.

A nice woman in a toyota decided to smash up the front of my CBR last week. Had to get all new front and side farings and a new front headlight.

Picked the bike up yesterday and it hasn't sounded so smooth since I first rode it out of the dealer. All rattles gone except for that slight hum from 6/7000rpm that you'll get with a single.

I always suspected that it was something like the dash/headlight/front farings, and it seems to be. I've only put 50 or so km on it since yesterday, but what a joy to listen and feel the bike as it should be. Here's hoping it stays away.

Out of all the pieces removed I'd guess the headlight was likely to be the main culprit, if indeed it was something to do with all the pieces they changed.

Will report back, whether it develops again or not.

I have to say that I *think* my bike lost it's rattling sound after I did my valve inspection. Since then I have not heard a thing in this regard. I did notice that the bolt holding the plastic piece that spans the area below the seat and the tank (on the right side) was pretty loose.
It could be that it WAS this loosely fastened piece making the sound and that when I buttoned everything back up, the properly tightened bolt got rid of the sound. Don't know for sure, but the sound has been gone since I did that.

 

[jasinner]

Thanks whoever suggested tightening all the nuts and bolts down. That fixed my problem.