Yamaha 9.9 4T oil consumption

[pakostane]

Not sure if this instruction is for your motor, but this is what it says:
[IMG]F9.9PistonRings by Charles Postis, on Flickr[/IMG]

But in any case, re-used rings should be placed on the same piston and groove where they came from.

Others should elaborate.

Does anyone has repair manual for F 9.9 MSH2. I can not find on net.

[pakostane]

It is 63$. Can someone just send printscreen of ring ends gap?

[pakostane]

On this document data looks much better. 0.55 is limit gap. Tomorrow I will get cylinder in machine market for measure.

[cpostis]

[QUOTE=cpostis;131821]Here you go. Again, this might not pertain to your non-USA/Canada motor, but more than likely will.
Private message me with your e-mail address, and I'll send you a gift!!


This information is incorrect, It is for a two stroke. I apologize for the
misinformation, I shall try to delete.

Quote has been deleted. I have been in touch w/OP via e-mail and he is aware of this.

[pakostane]

Does anyone have this info for F9.9 4T engine?

[99yam40]

This information is incorrect, It is for a two stroke. I apologize for the
misinformation, I shall try to delete.

Chuck, you will need to delete the quote also to make it all disappear

[pakostane]

https://www.google.hr/url?sa=t&sourc...0c_X_fEak8_UMg

I found here service manual for my engine.

[pakostane]

Finaly when I found repair manual I made measurements. This is result:

Old rings:

1st. 0.5mm
2nd. 0,5mm
Oil: 0.9mm

New rings:
1st. 0.2mm
2nd. 0,35mm
Oil: 0.65mm

All new rings are in tolerances. I can assembly engine.

[TownsendsFJR1300]

Quite a bit tighter, Should run good!

I believe the piston ring end gaps should be 1/3 the way around the bore from each other. You may want to check on that...

[pakostane]

With new piston rings and valve seals my engine still has same oil consumption as before. Two months ago I noticed isome demage on fuel pump diaphragm and some of fuel pass in oil. I thougt it is cause oil consumption. I changed it but engine has still same oil consumption. I think only solution is buy new engine -

[99yam40]

Did you hone the cylinders so they could break in the rings?
did you run the motor to break in the new rings?

[pakostane]

No cylinders did not hone. Just new rings and seals.

[cleddau1]

a creaking gate hangs the longest

I think I posted earlier suggesting that you just keep topping up the oil if the motor is going OK otherwise.
Would have saved hassle and expense and it is still going to be cheaper to top up than buy a new engine.
Old engines use oil but can still have plenty of life left....

[99yam40]

No cylinders did not hone. Just new rings and seals.

cylinders are honed so the rings and the cylinder walls can wear in together properly.

[pakostane]

I did not hone cylinder because I did not want to disassemble head. I changed valve seals and head gasket 2 months before rings. When it did not stop oil consumption I decided to change piston rings but without head disassemble head. But oil consumption is same as before oil seals and same before rings.