Knocking.

I heard a knocking sound coming from somewere, not sure were. Happened at the end of a 20min ride. Didnt do it after i left it to stand and started it up again....?

Is it the top end on its way out? If so, were can i get the bits for the rebuild?

Cheers.

PS. My exhaust isnt connected properly at the manifold (no bolts) and the temp guage goes straight to the hottest after about 2mins of riding. Weather im moving or not. (These may be the cause of the engine getting damaged.)

The bikes getting stripped and fixed up completely. But i just want to know wether the knocking sound is usually a sign that the top end is going to go... thanks.

 

still not sorted out ur exhaust lolol

 

wont the knocking be the exhaust not connected properly?

 

Nah i aint sorted the exhaust yet

The exhaust has been like that for a while so surely i would of heard it before. So i dont think its the exhaust, as thats making a rattling noise. This knocking was in time with the idle, Like when i was just at a stand still it would knock at a steady pace, then once the revs built up it went quicker then died away. It only knocked at low revs, between 1-4

 

Is the engine very vibey mate. Mine made some nasty noises before I completely destroyed the bottom end but it felt vibey as fook for a while before..... Piston slap maybe..??? Might be worth taking the top end off just to see whats going on.

 

Vibey?

Yer im going to be taking a look this weekend.

Ta.

Btw, You've scared me now with the bottom end thing

 

Doubt it's that... sorry mate.... I'd done 26500km and screwed it majorly lol. I'd had it pinned at top revs for a couple of miles as well so I wasn't doing it any favours haha.

 

but surely the exhaust will come looser if u aint sorted it! perhaps its tryna chat to u in morse code haha while your at a standstill try knocking back haha

 

Morse code lols.

It cant get any looser as its not screwed on apart from on the side.

 

It sounds like your engine is f*$ked M8. You nead a new one. You may get away with a top end rebuild. as regards to your over heating does it have any water in it?

 

Yeh loads. I dont think its actually using it. Must be a blockage or something.

And yer, i hope i do get away with the topend rebuild lols.

 

wack it with a hammer! lolo! did u try knocking back like i said? haha

 

Nah i didnt want to piss it off

 

haha doubt u would of pissed it off lol he might be a transformer tryna get out! wooo! wish my bike was a transformer lol

 

Stripped it down, the piston rings are fine, but the piston is burnt... Does it need replacing if its burnt ?

There wasnt a drop of coolant in my bike. I lol'd.

 

Knocking is caused by the bearing ( Big and Little) being worn, Have you checked them? You say that the rings are ok what did you use to check them? is the barrel ok?

Can you post a pic of the top of the piston? I would like to see the "burning". Most 2 stroke pistons will have a build up of carbon on the top of the piston this can normal be scraped off with a hard piece of wood or a piece of plastic.

Si

 

I will get some pics up tomorrow. It it slightly burnt on the side. I havent checked the bearings as i need my bike so it was a case of have a quick look and whack it back together and hope it works.

We are dropping the engine out next weekend and replacing all the gaskets, top and bottom. Im also fitting a new piston and rings. If you think the knocking is the bearings ill get some new ones...

I found why it was over heating and that was because the collant was just pissing out of the engine.

When we put it all back together today. We put all new gaskets on the topend and its loosing compression and the gaskets arent sealing properly so we think its warped the top end with the heat.

 

Ive found the top end bearing on this site, but im not sure were the bottom end bearing are...

http://shop.wemoto.com/index.dyn

Is it the "Main Bearings" Left and right?

Its the Yamaha DT 125 R (01-03).

 

Your main bearings are on the end of the crank left and right as you said. but your bottom end bearing goes between the crank and the con rod. You will have to split the crank cases to replace the mains and the bottom end bearing. You will still have the water problem to sort out. The cheapest, quickest, and easyest way to solve the engine is to get another one from a breakers or even Ebay. the cost of all the bearings a gasket set, rings, pistons, and maybe a haed skim will be more than what you could get an engine for.

Si

 

Ive already bought a piston set and a topend gasket set. But i suppose they will come in handy someday.

Cheers mate, ill have a scout around ebay.