Rattley startup

Thread Tools
 
Search this Thread
 
  #1  
Old 05-13-2008, 06:36 PM
dadalus23's Avatar
Junior Member
Thread Starter
Join Date: May 2008
Posts: 9
Default Rattley startup

My '07 is super rattley when I start it with the choke on. Is this normal? After the choke is off, it sounds pretty good, but it really sounds rough those first couple of minutes.

Thanks!


 
  #2  
Old 05-13-2008, 07:03 PM
markmeinteil's Avatar
Senior Member
1st Gear Member
Join Date: Jun 2006
Location:
Posts: 5,762
Default RE: Rattley startup

Sounds like a cam chain tensioner issue. If you still have a warranty, take it to the dealer now.
 
  #3  
Old 05-13-2008, 09:10 PM
calamarichris's Avatar
Senior Member
1st Gear Member
1st Gear Member
Join Date: Sep 2006
Location: La Costa, CA
Posts: 807
Default RE: Rattley startup

First couple of minutes... ?!?!? [sm=noooo.gif]
How long are you letting the bike idle with the choke on?
Many people seem to think they're helping their engine by letting it 'warm up' for several minutes with the choke on. This is actually very harmful and will considerably shorten your engine's lifespan.
~Sit on the bike first and prop it straight up-n-down between your legs. (This allows the oil in the cylinder head to spread about uniformly, rather than pooling over to the left when it's on the sidestand.)
~Start it up, using only as much choke as it needed to keep the engine running while you put on your helmet and gloves.
~Then ride gently away, closing the choke as soon as possible and keeping the rpms below 3500 for the first mile.

The best way to warm up an engine is to vary the rpm with minimal load. Riding the bike gently and not zinging the engine is the way.
Good luck and let us know how it goes.
Peace!
-CCinC


 
  #4  
Old 05-13-2008, 09:18 PM
dadalus23's Avatar
Junior Member
Thread Starter
Join Date: May 2008
Posts: 9
Default RE: Rattley startup

Thanks for the feedback.

I definately don't leave the choke on for any longer than I need to (I've been reading this forum!). Sitting on the bike while first starting may be a good idea though. I usually start it while off the bike. The clackety-ness of the engine lasts as long as the choke is on, whether full or half (which I do after about 20 secs.) and then, when the choke is off, it sounds much better.

I'm just wondering if your other bikes sound like this on initial startup (choke on) and maybe it's just a characteristic of this engine or if they purr like kittens and mine has a cold!

Thanks again!
 
  #5  
Old 05-13-2008, 10:02 PM
calamarichris's Avatar
Senior Member
1st Gear Member
1st Gear Member
Join Date: Sep 2006
Location: La Costa, CA
Posts: 807
Default RE: Rattley startup

Every internal combustion engine is a little noisier when cold. The internal metal parts expand as they heat, which means that the clearances between them is wider when the engine is cold. More clearance = loose fitting = noisier, clattery.
But if it suddenly gets quieter when you shut off the choke... that doesn't sound normal. I'd take that to a dealership and let them listen to it. It should be covered by warranty if you bought the bike less than a year ago.

Finally, this bike will never be as quiet as an inline-four with shim-under-bucket valves. More moving parts = more noise. BUT the additional moving parts in the 500R's engine allow you to adjust the valves without having to remove the cam, the camchain tensioner, the cam caps, the airbox, the carburetor assembly... There are plusses and minuses to every design.

Most riders seem to like louder aftermarket mufflers, because the louder exhaust noise drowns out the engine's natural mechanical noise. I went the other way, by putting sound-absorbing foam on the inside of the fairing and under the gas tank:


I don't understand why Kawasaki puts this stuff on bikes with the quieter engines, but not on our clattery 500R.
Good luck and let us know how it goes.
Peace!
-CCinC
 
  #6  
Old 05-14-2008, 03:04 AM
fnpaulie's Avatar
Senior Member
1st Gear Member
Join Date: Mar 2008
Location: Long Island, NY
Posts: 107
Default RE: Rattley startup

What makes it more clattery? The 500 that is.
 
  #7  
Old 05-14-2008, 06:08 AM
markmeinteil's Avatar
Senior Member
1st Gear Member
Join Date: Jun 2006
Location:
Posts: 5,762
Default RE: Rattley startup

The stud & nut adjustment type valve rockers on the 500R, and 250R models tend to make a louder clattery sound than shimmed type valve trains. There's nothing to worry about, it's just the nature of the beast.
 
  #8  
Old 05-14-2008, 03:43 PM
calamarichris's Avatar
Senior Member
1st Gear Member
1st Gear Member
Join Date: Sep 2006
Location: La Costa, CA
Posts: 807
Default RE: Rattley startup

It isn't the locknut assembly at the top of each valve that is making the noise exactly.
On our bike, each cam lobe presses down a rocker arm, which presses TWO valves open:

See the slotted heads with the pink paint on them to the immediate left of my thumb, above? Notice there is only one cam lobe for two of them. That rocker arm is mounted on a shaft:

Those pretty chrome ***** on the side of our engine (to the left and below the camshaft in this photo) are the shafts that the rocker arms are mounted on.

On the other hand, here is my '02 ZX9R. On a typical shim-under-bucket design, the cam lobes press the valves directly, with no rocker arm or shaft:

It's difficult to see, because it's a small, tight little assembly. The only things between the cam lobe and the valve stem are a cam follower (also called a 'bucket'):


And a shim, which come in various sizes to ensure you've got the correct clearance:

The ZX9R has fewer moving parts between the cam lobe and the valve itself, which means less noise, lighter weight, higher available rpm and less wear. BUT it's a pain in the @$$ to change those little shims every 6500 miles.

Another reason why our bike is slightly noisier than the more modern Ninjas is because we have a primary chain between the motor and transmission. I suspect the reason Kawasaki left this on our bike is to absorb the uneven power pulses associated with our 180-degree firing order. I thought only Harleys did this anymore and was surprised to learn that our bike had one. Because an inline-four engine is perfectly balanced, the motor can be linked directly to the gearbox. Having a primary chain drive absorbs some of those uneven power pulses.

Peace!
-CCinC
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
xjayy
KX250 & KX250F
0
06-23-2013 09:57 PM
T_i_G_e_R
KLX 250S
37
05-27-2011 07:57 AM
SpeedNStylez
Ninja 250R
11
01-25-2008 12:16 AM
Born2Drive4Ever22
General Tech
8
10-25-2007 03:50 AM
sjo102784
Ninja 500R
8
02-06-2007 06:23 PM



Quick Reply: Rattley startup



All times are GMT. The time now is 11:14 PM.