Greeting to fellow 400cc rider out there.
Im currently located in Singapore and im aware this is a european based forum.
I have pretty much emptied my resource and would seek urgent help to whom it may concerns.

While riding on my RVF NC35, 1997 make, when i reach 4 to 5 to 6 rpm, i could hear a pretty decent knocking sound coming from under the tank. Im aware that a tickling sounds refers to valve clearance required.

As my bike does have the tickling sound, I knows that i need to do valve clearance. But Im really puzzled with the knocking sound.

I check with one of the bike shop, he told me its conrod giving way. ( But he does not specialized in big bikes but more so towards smaller cc bike )
Therefore, i went to another bike shop, who specialized in RVF NC35. But same thing, he told me its conrod.
And lastly, I went to one more final shop, who specialized in big bike. Here is the curious thing. He told me to do valve clearance as there was the tick tick sound and the shim is loose ( which i agree ). But he cant actually figure out whats the knocking tok tok tok sound. He say he suspect piston loose, either that or conrod.

Okay heres my doubts. Should i just give it to either the previous 2 shop and ask them to overhual the engine where the problem they diagnosis is conrod, or should i risk it with the 3rd shop?

If its really piston that is causing this tok tok tok knocking sound, the repair would be a rough estimate of 500-600. Which would really save me alot, as the conrod repair would set me back rough estimate of $2000.
But I was just wondering, if the 3rd shop owner already know its the conrod problem, but he trys to rip me off by saying it could be the piston and ask me to open up the TOP engine. And if piston is alright, i would have to pay him workmanship and continue with the bottom engine overhual.

Im sort of looking as a $300 vs $2000 chance.

I was wondering has anyone has those knocking tok tok tok sound before? And if so, Is it really the conrod or could it be other problem?
Any general input would be greatly appreciated.
(:

Welcome..

Any chance you could take a recording of the noise and post it on here?

I would suspect if it is a proper knocking/clunking noise then your main bearings are going.. Check your oil - is it nice and clean? have you enough of it? If you can, drain the oil and have a very close look to see if there are any brassy particles in there.

Noisy valves are not really that audible..certainly not enough to be making knocking noises..

Sorry for the bad news...but check the oil out and let us know.
I would not ride the bike at all if I was not certain about this., My own bike, No9, is off the road due to this knocking and I am sure the main bearings are dead...

I have another engine to fit...far cheaper than rebuilding.

I doubt its possible to record the sound. it has to be riding at 4-6 rpm or above.
How do i check for the oil? I used to ride a kawasaki krr 150 for 3 years before moving on to a 400cc. I feel so totally useless in terms of knowledge to the bike.
So what happens if there are brassy particles? what does it mean?

And main bearings you mean conrod bearing or ?.
Sorry for the imposed but thanks for coming in and helping out..

OK - if it is the main bearings - conrod onto thje crank - then if it is wearing out or damaged (hence the knkcking) then there will probably be some pieces of it in he oil.

Check the amount of oil in the bike first. Unscrew the dipstick (by your right leg - on the motor) and with the bike upright withdraw the diptstick, wipe it clean and then re-insert, but not screw in. The pull it out, see whether there is enough oil in the bike. If it is too low...then it might be the cause of the failure.

Under the bike is the oil drain bolt - 17mm

get a container and let the oil drain into it - watch it as it comes...it should be obvious if there is anything in the oil that is metallic.

If so...try and find another engine.

If not..then you can re-use the oil (though I would change it anyways_

Oh i roughly get what you meant. So its like the procedure of changing engine oil.
Okay so, if there is anything metallic in the engine oil, it means that the main bearing (conrod) is giving way and it leaves particles to the engine oil, and thus a overhaul is needed. ( you mention find another engine ).

And if there is no particles, does that mean that the particles have not sink into the engine oil compartment but it would just be a matter of time?

So basically you do agree that its the conrod bearing is giving way from the way i describle it.
do you happens to encounter this before?

if no particles, you might be lucky and it may be something else.

From your description and the fact that 2 of 3 other people suspect the same..it sounds like it could be a dying engine.

My own bike has had this issue - I did a trackday at Donington park and when I started my bike for the 3rd session it was making a clacking and knocking noise.. The bike has not run since then and I have a different engine to fit into it.

why post this in multiple places ? FFS seriously did you think you would get a faster response by spamming the board ?

just replace the engine with a good used one. cheaper and less stress. the end

hello my friend. I just went to check the oil. I dip in and pull it out, it fills about 1/4 going 1/2 of the stick. is that good enough? and when i wipe it on a piece of tissue paper, there is no metallic stuff or anything except the oil..

CRM wrote:why post this in multiple places ? FFS seriously did you think you would get a faster response by spamming the board ?

just replace the engine with a good used one. cheaper and less stress. the end

sorry man, i didnt know where would be the right place to post

I would say the tok tok tok sound is a big end, its f****d bin it or get another crank and rods or motor.