1978 Garelli Gran Sport

Is this component supposed to easily come out of its place? I just installed new piston and rings and engine makes a clanky noise. Does this supposed to easily move side to side?

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Re: 1978 Garelli Gran Sport

Yes. It'll tighten up when you put the piston pin in it.

Re: 1978 Garelli Gran Sport

It doesn’t seem to tighten. It stays loose Stephen. Could piston be knocking side to side because of this? Piston pin slides also when inside (edited)

Re: 1978 Garelli Gran Sport

Is the rod loose on the other end? Like the bearing might be bad?

Re: 1978 Garelli Gran Sport

The rod part attached to inside of engine is nice and tight. The rod doesn’t move but the bearing slides easily from side to side. It also very easily slides off the rod. I’m wondering could this be causing the clacking noise when engine is running due to piston hitting inside intake? (edited)

Re: 1978 Garelli Gran Sport

The wrist pin bearing has to have side play in order to self-adjust inside the cylinder .

New piston ??? did you go oversize and to fit the worn cylinder ?

Did you measure the piston to cylinder clearance ?

When on the rod , how much play does the piston have in the 'in and out' direction , as if in the cylinder ?

You might be hearing piston slap .

Re: 1978 Garelli Gran Sport

Piston Arrow points downward right towards exhaust right?

Re: 1978 Garelli Gran Sport

> Dave Jenkins wrote:

> -------------------------------------------------------

> Piston Arrow points downward right towards exhaust right?

Yes .

Re: 1978 Garelli Gran Sport

> Dave Jenkins wrote:

> -------------------------------------------------------

> Piston Arrow points downward right towards exhaust right?

The vast majority of the time, yes, but there are a few exceptions. Depends on the specific motor and kit.

Re: 1978 Garelli Gran Sport

> Dave Jenkins wrote:

> -------------------------------------------------------

> The rod part attached to inside of engine is nice and tight. The rod

> doesn’t move but the bearing slides easily from side to side. It also

> very easily slides off the rod. I’m wondering could this be causing the

> clacking noise when engine is running due to piston hitting inside

> intake?

Exactly when do you hear this "clacking" noise? At idle, midrange or wide open? Or is it all the time?

Re: 1978 Garelli Gran Sport

All the time the engine is running.

Re: 1978 Garelli Gran Sport

No I didn’t go over size. I didn’t measure I ordered the standard size for my engine. Not a lot of play in piston in/ out direction.

Re: 1978 Garelli Gran Sport

I have standard piston/ rings for Noi engine

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Re: 1978 Garelli Gran Sport

> b to the eff wrote:

> -------------------------------------------------------

> > Dave Jenkins wrote:

>

> > -------------------------------------------------------

>

> > Piston Arrow points downward right towards exhaust right?

>

> The vast majority of the time, yes, but there are a few exceptions.

> Depends on the specific motor and kit.

Please , enlighten me , as I've never seen a piston arrow point any other place than the exhaust . It just happens to indicate the direction of flow .

Re: 1978 Garelli Gran Sport

> P D wrote:

> -------------------------------------------------------

> > > Piston Arrow points downward right towards exhaust right?

> >

> > The vast majority of the time, yes, but there are a few exceptions.

> > Depends on the specific motor and kit.

>

> Please , enlighten me , as I've never seen a piston arrow point any

> other place than the exhaust . It just happens to indicate the direction

> of flow .

I don't recall the specific example where the arrow was backwards, but it does happen. I'm sure it will surprise you to learn that mistakes creep into our cheap little motors sometimes.

Always look at the ring lands vs the ports, and if there's a window in the piston, it should face the intake.

There are also plenty of kits without any markings on the piston, such as the T3 airsal for peugeot 103. The 48mm V1 BRN kit has no arrow on the piston either.

Re: 1978 Garelli Gran Sport

I do remember reading about one brand of ped that the arrow points up but its not Garelli.

Re: 1978 Garelli Gran Sport

I believe it’s Franco Morini. The ring lands point up. (edited)

Re: 1978 Garelli Gran Sport

Sheez post a vdo of the knocking. Most likely its just 2 stroke noise. More picts help besides wrist pin bearing.

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