Piston Needle Bearing

[samo]

Hi!

Does anybody knows wich needle bearing for piston should go for 270 beta 07 model? I know the measurements: 18x22x22, but there is probably some specific one...like main bearings 6206 zz c3.

I hear some noise in piston when I turn trotle off from ( don't know exactly ) about 4000rpm. Just one click or two, like two metal things knock against each other.

So I'll change both main bearings, piston bearing and piston rings. Is there something more to change? I mean preventive.. like to have motor in good shape

Samo

Edited June 24, 2009 by samo

[samo]

Nobody??

Piston needle bearing?

[16000rpm]

Hi

A good bearing factor will be able to supply a bearing using the dimensions .

Chris

[gjbiker]

Have a looky here - Bearingboys

GJ

[samo]

Thanks. I looked here " Bearingboys", but they don't have such 18x22x22 bearing.

I spoke with J.Lampkin (per mail) and from my description he said that piston should be the trouble. I have to check con rod he said. Is that piston pin? I'm no good in English

I'll order by him everything for piston for now (piston pin, piston rings and piston bearing). He is very friendly and helpful.

[gjbiker]

Con rod = connecting rod between piston and crankshaft

Piston pin ? Gudgeon pin holds piston to con rod with small end needle bearing.

Check play in both small end and big end (crankshaft) bearings by applying an up and down motion whilst either at bottom dead centre or top dead centre and feeling for wear.

Main bearing play can be checked by the feeling for up and down movement on the flywheel and the primary gear ends of the crankshaft.

If you are purchasing a piston kit (piston, rings, pin, and bearing) check for big end bearing play when the old piston has been removed.

Hope this helps?

GJ

[samo]

Thanks GJ. I'll check today where is the play.

Samo

[stevew4130]

To bring up an old post, when checking for play in the conrod should you expect movement side to side but not up and down? Myself and my dad are trying to diagnose a loud engine knock in his '99 techno engine and we have removed the engine and took the barrel and head off and we're now just checking for play everywhere, there is no movement up and down but side to side there is..

When the engine was running it was very loud and knocking, if you felt the barrel/head you could feel it too. Anyone have any thoughts on this and what we should be looking for?

Thanks

Steve

[nzralphy]

My bike used to do that. It was fuel pinking..... I changed the fuel to 98, polished the piston, and got the jetting a little richer in the mid range and it almost went away. Almost.

[stork955]

Gday, same here, my old Techno had a light knock and I stripped it to check. Piston to bore clearance was perfect, small end and gudgeon (or Wrist pin, Piston Pin) all OK. I replaced main bearings which were not too bad and measured the rod - there was no freeplay up and down which is normal and side clearance was wide but not too bad. I cant remember how much it had but probably in the order of 18 thou (about 0.4 mm) measured between the conrod and the crankshaft. This is usually an indicator of a failing big end way off in the future. Rule of thumb says that max rod side clearance should be no more than 20 -25 thou (around 0.5 mm). Put it back together and it was the same afterwards but ran much better because everything was clean!

Cheers,

Stork.

[stevew4130]

Cool thanks for your replies! I've just spoke to my Dad again and he says there is a fair bit of movement sideways on the con rod so I guess the big end bearings are worn?

Thanks

Steve