Hey guys, I have a 95 CB1000 with 58k miles. My beloved uses the same engine as the CBR1000F and I used the great How-TO on this site to do a recent valve adjustment. (I also have the factory service manual)

My bike has gradually (over the last 5k miles) developed a ticking noise which sounds to be coming from the top of the engine. The noise goes away once the engine is fully warmed up, but I guess I'm slightly worried by it. I thought the valve adjustment would cure the ticking but it didn't make a difference. If anything, it's slightly worse now. (The engine has the usual noisy cold-cam-chain too -- but I know not to worry about that.)

When I did the adjustment, it was actually in pretty good spec, with one exhaust valve being slightly too tight and a few others needing to be tightened up. I've done valve adjustments before on Honda cars, so the bike was actually pretty easy and run of the mill.

Is this engine known to tick, as so many other Honda motorcycle engines do? Should I be worrying about this? I'm tempted to open up the valve cover to double-check my clearances ... but I actually double-checked them all after tightening the adjusters down to 7ft-lbs and everything was good.

The bike runs great still. Very powerful, always starts right up... no other issues. I use Rotella T 5W40 with frequent changes... Commute on the bike mostly so she gets driven gently in city traffic. Occasional weekend trips up into the canyons for some fun. (Like last weekend)

Thanks for any input! ---Adrian

Here's a couple of photos from the recent valve clearance adjustment:
http://www.flickr.com/photo_zoom.gne...390&size=l
http://www.flickr.com/photo_zoom.gne...390&size=l
http://www.flickr.com/photo_zoom.gne...390&size=l

 

I thought that the engines were very simular but not the same
(5speed/6speed and cabbies), not talking from experience here, so I could be blowing smoke

 

1. Ticking could just be CCT which is noisy until warm.

2. Could also be valves. A freshly adjusted valve should be a little noisy. They tend to get loose over time and people think they are noisy when they have been freshly adjusted. Always better to have em a little noisy than not.

I thought the CB1000 used different cams/carbs to give it more mid range, or I could be blowing smoke too.

 

You guys are right -- in that it uses a 5-speed (vs 6) and has different carbs and cams for mode mid-range punch. My particular bike has carbs off a CBR600F3 (if I remember correctly) rejetted to perfection. The first (and previous owner) worked for Honda in Torrance, CA and he spent a lot of time modding the bike with Honda parts from a bunch of different bikes. Wheels are off some other bike (smaller), headlight is off some cruiser, exhaust is off some other Honda bike, carbs from the CBR, etc. He must have had access to the entire parts catalog and had time to see what fit, etc.

When I did the valve adjustment, I used the clearance specs from my service manual, but when I recall, they were the same as the How-To on this site. The previous owner actually gave me the Honda parts list for my bike and the parts list for the CBR1000F. I recently used it to see if the clutch and associated assembly was the same between the two bikes -- and it is. Exactly. (He had told me the basket on the CBR1000F was better or stronger, but the Honda part# is identical.) I'll look up the cam part# to see if it differs.

Believe it or not, when I bought the bike the guy gave me an entire spare engine/trans assembly from a CBR1000F! It's sitting in my friend's garage. The owner of that engine had used a little too much RTV when putting the valve cover back on and ended up clogging up and oil passage or something, so it has top-end damage. But the bottom-end and trans is still in great shape, and it was my bike's previous owner's intent to put transfer the 6-speed over to my bike.

Anyway, here is something strange. When I got home from work last night the engine wasn't even fully warmed and was ticking. (I only commute two miles each way.) Well, I noticed that when I put the bike on the side stand the ticking went away.

Isn't that strange? Take off center stand rev it a couple of times and it's ticking. Back on side stand and it goes away. So maybe it really might be the CCT?

Then today on the way to work, the bike wasn't really ticking much. Oh, and I noticed it doesn't tick at all when I first start it up....

I have a feeling I'm just being overly paranoid here. I can only hear the ticking when at idle, even when revved up past 1500rpm you can't hear it anymore (either drowned out from the engine noise or it's not doing it.)

I'm going to buy a stethascope to try to listen more closely to where it's coming from.

 

Hey guys -- I am just looking at the parts list for the 94-95 CB1000 vs 93-95 CBR1000F.

The cams are the same! Part numbers are identical. The only difference on the entire valvetrain assembly is the CBR1000F has a double valve spring setup while the CB1000 a single spring. No doubt to handle the higher red line.

The cylinder head is silghtly different -- looks like the casting has some additional mounts on the CBR. Head gasket is different. Piston is different, but nothing else in that area. (Same crank even.)

Carbs are different. VP47A in California vs VP86A in Cailfornia on the CBR.

So it's pretty interesting that the only real engine differences on the bike are the carbs, pistons, valve springs and exhaust system. (And the 6-speed)

What's the redline on the CBR? The CB1000 has a 9000rpm redline.

 

Are the rods the same? Make me wonder if the CB1000 has a longer stroke & narrower bore motor for more low down.

 

Yep, rods and crank the same, so the stroke is identical. I would imagine the different pistons yield higher compression on the CBR probably .. I don't have any info on the CBR in my book, but here is the specs for the CB1000:

Bore x Stroke: 77.0 x 53.6
Displacement: 998cc
CR: 10.0:1
Carb throttle bore: 34mm

So maybe the CB1000 engine really isn't that detuned? Smaller carbs and a more restrictive exhaust should yield less top end and more mid-range, but I think it'll mostly just cut the top-end.

What's the red-line on the CBR1000F?

 

Red line is at 10500 rpm

Edit: CR for my '90 is 12,5 according to the Haynes manual

 

10500 red line My cam chain use to make a noisefrom 1500 to 2000 till it warmed up took it to the track for a good flogging and now there is not a noise.