What's that noise ?!!!!!

Yilt · July 07, 2011, 06:47:00 PM

Hi folks, i'm new on this site, and in case you are wondering, I've posted an introduction in the appropriate place, as I don't want to upset anyone. I bought my bike, a 1992 FJ 1200 with 16000 genuine miles on the clock. Not in great condition, but a lot of TLC later and she's looking superb. I rode her home for 70 miles or so and she rode faultlessly. Today I decided to service her, and firstly changed the plugs and air filter when cold and decided to start her up, ready for the oil change. When I started her up, OMG, what a noise !!! She sounded horrendous ! The bike didn't sound like this when I took her home. The noise appears to be coming from the top end. It's a continuous knocking sound, like the valves are way out, or something rattling around in there. The engine knocks at idle, tick over, which is set at 1100 rpm. When I rev her up, the noise becomes louder. I put a screwdriver on to the motor and it does seem to be coming from around the rocker cover area. I double checked the plug installation, and the plug lead firing order which are correct. The air filter is sitting tight aswell. I just don't get it ! Any help would greatly be appreciated, many thanks.

racerman_27410 · July 07, 2011, 06:48:58 PM

is there any oil in the engine ?

KOokaloo!

Frank

Yilt · July 07, 2011, 06:51:20 PM

Quote from: racerman_27410 on July 07, 2011, 06:48:58 PM
is there any oil in the engine ?

Yes mate. First thing I checked when I bought the bike. Cheers

KOokaloo!

Frank

Yamifj1200 · July 07, 2011, 07:34:39 PM

If the bike was running fine (quietly) when you rode it the 70 miles home. I'd say to take a look at the ignition wires since you just replaced the spark plugs of make sure you replaced them with the correct spark plugs set to the correct gap. If the spark plug wires are in the wrong place it might not run to well. Just a thought...

Eric M

Marsh White · July 07, 2011, 09:49:36 PM

+1 to the wrong wires on the wrong plugs. You also put in NGK DPR8EA9 plugs or equivalent right?

Yilt · July 08, 2011, 02:57:15 AM

Yes, the correct spark plugs were put back into the bike, and in the correct firing order. Can I just confirm with you all, that the firing order is 1234 from left to right as you sit on the bike. The plug wires are numbered in this order, and the Carb inlet rubbers have this firing order written on them aswell. I think i'll put the old plugs back into the bike and fire it up to see what happens. Thanks for the replies so far.

NJona86FJ · July 08, 2011, 03:18:23 AM

i thought it was 1243? checking now...

Yilt · July 08, 2011, 04:19:12 AM

Put the old plugs back in and still the same.

NJona86FJ · July 08, 2011, 04:29:34 AM

my bad...i get what you mean? the plug leads are numbered 1 2 3 4 but that isnt the firing order... thats just to link plug to correct wire ( forgive me if im telling you something you already know) as you sit on the bike L to R 1 2 3 4 yes. that would mean 1 and 4 come from the left hand (clutch side ) coil and 2 and 3 of the r h coil. its making me wonder that if its all wired up like this then maybe a defective plug lead? i had a crack in one of my spark leads and only found it by touching the lead ( by accident) while it was running... i dont endorse this it bloody hurt!!! i think you can check for contiuity with a multi meter... but the facts are alluding me now...( dropped a one inch drive rattle gun on my face while lying under a machine removing bolts... and yes that bloody hurt too!!!) hopefully someone will come in with more help..... i do know that however if your plugs arent firing right it sounds like theres a gremlin with ahammer in your engine....

Yilt · July 08, 2011, 05:31:35 AM

Quote from: NJona86FJ on July 08, 2011, 04:29:34 AM
my bad...i get what you mean? the plug leads are numbered 1 2 3 4 but that isnt the firing order... thats just to link plug to correct wire ( forgive me if im telling you something you already know) as you sit on the bike L to R 1 2 3 4 yes. that would mean 1 and 4 come from the left hand (clutch side ) coil and 2 and 3 of the r h coil. its making me wonder that if its all wired up like this then maybe a defective plug lead? i had a crack in one of my spark leads and only found it by touching the lead ( by accident) while it was running... i dont endorse this it bloody hurt!!! i think you can check for contiuity with a multi meter... but the facts are alluding me now...( dropped a one inch drive rattle gun on my face while lying under a machine removing bolts... and yes that bloody hurt too!!!) hopefully someone will come in with more help..... i do know that however if your plugs arent firing right it sounds like theres a gremlin with ahammer in your engine....

Thanks mate, checked the firing order and that's all set up correctly. I took number 3 plug lead off the plug, and it's the only one out of the four that's giving me a shock. Could it be number 3 wire is bad ? The problem I have is that I believe the wires are integrated into the coils on these bikes and can't be changed individually, without purchasing a new coil. Am I right in saying this, or talking crap ? Cheers

movenon · July 08, 2011, 09:46:23 AM

Might read this post http://www.fjowners.com/index.php?topic=2409.0 . It gives some info on changing a plug wire. Note that is is solid core wire, resistor is in the plug cap. Looks like you can change it out. I have no real experience changing a wire out, just relaying what I read. Good luck, let me/us know your out come.

Yilt · July 08, 2011, 02:08:19 PM

Thanks again for the replies, here's the latest update. Tested all wires and spark plugs, gaps etc and all is fine there. The sound is definitely coming from the top end of the bike and continues to knock with the rev's of the machine. The bike will tick over great, you can rev it and no loss of power, and no smoke coming out of the exhaust. It runs strong and would be perfect if it weren't for the knocking noise. I removed the Rocker cover and there's plenty of oil being pumped to the top of the engine. I looked for any obvious signs, but could not find anything. The Shims were all sitting nicely and all the fasteners at the top end were solid with nothing loose at all, and no obvious signs of damage at all. I'm now wondering whether the Cam chain tensioner is at fault here ? Anyone have any thoughts on that ? Forgot to mention, the Camchain at the top of the engine was nice and tight, and not loose at all.

simi_ed · July 08, 2011, 02:37:22 PM

Well, here's my 2¢: You've got the plug wires crossed, or you losta small part into a cylinder when the plugs were out. I hpoe it's only the wires.

Best of luck!

Ed

Yilt · July 08, 2011, 02:44:52 PM

Quote from: simi_ed on July 08, 2011, 02:37:22 PM
Well, here's my 2¢: You've got the plug wires crossed, or you losta small part into a cylinder when the plugs were out. I hpoe it's only the wires.

Best of luck!

Ed

Thanks for the reply. The plug wires are all correct, definitely. I always take one plug out at a time and replace in that order. I don't recall anything falling into a cylinder as I always work in a clean environment, cleaning up as I go along. Thanks anyway mate.

flips · July 08, 2011, 05:14:02 PM

Hi there.
I know this is probably not it ,but my 2c.A while ago rejetted the carbs,put them back in,started her up...awful knocking noise......got louder when reved...looked...listened...pulled out hair....swore.....cursed...muttered...asked advice...removed carbs....checked.....put backin...noise continued worse...all of the above repeated afew times...turned out to be a rusted out pin hole on the engine side of no 2 header pipe.Hope this helps.

cheers Jeff.P

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What's that noise ?!!!!!