engine knocking during low rpm in first gear

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engine knocking during low rpm in first gear

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CBR >> Past CBR Models >> CBR 600F2 >> engine knocking during low rpm in first gear

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engine knocking during low rpm in first gear - 9/30/2006 2:36:22 AM

wheeler6747

Posts: 23
Joined: 7/2/2006
Status: offline

hi i posted a few days ago about a light knocking sound. i have pen pointed it to only 1st and second gears during very low (1-4) rpm. any ideas what tit could be, and is this really bad or just something needs adjusting. will it hurt the bike to keep riding to work and home?>

Post #: 1

RE: engine knocking during low rpm in first gear - 9/30/2006 10:42:29 AM

jasonty

Posts: 103
Joined: 4/30/2006
Status: offline

Is it a knocking sound constant with engine RPM, or is it something rattling in the engine that sounds like something broke off?

(in reply to wheeler6747)

Post #: 2

RE: engine knocking during low rpm in first gear - 9/30/2006 2:02:39 PM

wheeler6747

Posts: 23
Joined: 7/2/2006
Status: offline

it is strange it does not sound like something rattling around, but at the same time it not ver consistent with the rpm. i mean, when im in neutral and rev it there is no rattle. this is frustrating, if you have any ideas please let me know.

(in reply to jasonty)

Post #: 3

RE: engine knocking during low rpm in first gear - 10/1/2006 1:08:29 AM

undercoverbrother

Posts: 108
Joined: 6/10/2006
Status: offline

it could just be a vibration from metal on metal(ie tank n frame) u should be able to recreate it by gradually revin to see when the vibration begins and try n track it down that way. plus in these colder temps bike is gonna sputter a bit in lower rpm's. just a thought

(in reply to wheeler6747)

Post #: 4

RE: engine knocking during low rpm in first gear - 3/19/2008 8:24:36 PM

Barkstrom_JB

Posts: 81
Joined: 2/6/2008
From: Milwaukee, WI
Status: offline

i had the same problem on my F3. i was told it could be the valves...

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(in reply to undercoverbrother)

Post #: 5

RE: engine knocking during low rpm in first gear - 3/20/2008 5:46:50 AM

alejandrof2

Posts: 165
Joined: 3/8/2008
Status: offline

if your bike has over 14 k milles and never have the valves adjusted prob are the valves, and prob the noise still there at higher rpms but you cant ear it over the engine cause the faster you rev your engine the faster valves move and the pitch of the noise go to high and you will not ear it but still there, any mech will now if are the valves just whit ear your bike just drop in few places and see what they say

(in reply to Barkstrom_JB)

Post #: 6

RE: engine knocking during low rpm in first gear - 3/20/2008 4:46:37 PM

tao_victim

Posts: 112
Joined: 1/27/2008
Status: offline

ten bucks says your chain is improperly adjusted and needs to be lubed.

i had the same problem

< Message edited by tao_victim -- 3/20/2008 4:52:45 PM >

_____________________________

94 cbr600 f2
- -1/+2 (5 up)
-two brothers CF pipe
-stage one jet kit
-custom made fender eliminator
-integrated tail light
-H.I.D. headlight
-k&n air
-smoked windscreen
-more to go!

(in reply to alejandrof2)

Post #: 7

RE: engine knocking during low rpm in first gear - 3/23/2008 9:52:30 AM

Hershey

Posts: 886
Joined: 7/27/2007
Status: offline

I agree with tao_victim, and strongly disagree with alejandrof2.

If it is only making the noise while you are in motion, it's most likely chain slap that can be adjusted by moving your rear wheel back until you have about 3/4" of freeplay in the chain. A good way to tell if your chain is too slack is to lift it up and down and measuring the slack, also pull back on the chain at the middle of your rear sprocket - it should not come off the sprocket more than 1/8".

As for the valves, Honda valves are almost NEVER out of spec even after 60,000 KM.

The only other obvious answer would be the CCT.

But like undercoverbrutha said, the tank tends to vibrate against the frame rails and airbox. I fixed this problem with sticky sided foam tape along the frame and airbox lid.

_____________________________

I intend to live forever. So far, so good.

(in reply to tao_victim)

Post #: 8

RE: engine knocking during low rpm in first gear - 3/24/2008 9:28:17 AM

jahnaboi

Posts: 441
Joined: 8/29/2007
Status: offline

Considering you're situation, I strongly agree with tao_victim and Hershey. The chain tends to slap on the chain slider when its too lose. But on the other hand, if it happens in first and second gear during acceleration, I couldn't see it making too much noise unless it was at a constant speed where you let off the gas and on it. Try adjusting the chain to specs that Hershey specified and tell us how it goes. Then we could go down the probable list of problems.

-Jasper

(in reply to Hershey)

Post #: 9