Pro-X or OEM pistons for 07 1300R

[Robsauto2]

Hey guys, got my engine out, going to send the crank to get it phased, trued and welded. This ski has 98 hours on it and I found the rings are worn (.025" closed end gap) so i'm gonna rebuild with new pistons/rings, etc. I read here about some issues with the ring locating pins falling out and destroying the engine and sure enough, 2 of mine were loose and ready to fall out. Do the pro-x pistons have this issue? Or have the oem's been improved? Thanks!

[Prism]

I have personally used both. I had a set of pro-x pistons in my 2003 ski that I just removed after 105hrs. I had some detonation damage on the intake side edge of the cyl#3 piston. The pins were still secure. I'm replacing them with coated OEM pistons I bought from Lowell. I can tell you the coated OEM pistons weighed 393 grams each while the pro-x weighed aprox 374 grams. The pin loosening may be due to the forged construction expanding more and over time the pins eventually loosen. This is just my own theory and not all pins come loose on OEM but could be more likely to IMO. Not sure about Wiseco as they are forged as well, but my experience with them on snowmobiles has been positive. Being your ski is an 07 and the pins loosened, I doubt the issue has ever been improved by Yamaha. My results were positive with the pro-x as well.

[Robsauto2]

I have personally used both. I had a set of pro-x pistons in my 2003 ski that I just removed after 105hrs. I had some detonation damage on the intake side edge of the cyl#3 piston. The pins were still secure. I'm replacing them with coated OEM pistons I bought from Lowell. I can tell you the coated OEM pistons weighed 393 grams each while the pro-x weighed aprox 374 grams. The pin loosening may be due to the forged construction expanding more and over time the pins eventually loosen. This is just my own theory and not all pins come loose on OEM but could be more likely to IMO. Not sure about Wiseco as they are forged as well, but my experience with them on snowmobiles has been positive. Being your ski is an 07 and the pins loosened, I doubt the issue has ever been improved by Yamaha. My results were positive with the pro-x as well.

Awesome, thanks for the info. I'll give Lowell a call next week.

[flying dutchman]

I have had two oem pistons with pins loosening and spun rings. Search for "another spun ring" in forum.
WFO suggested to go with OEM pistons due to stronger skirts and that is what I did for all three at last rebuild.
I do plan to check the pins at 50 hours to prevent another damaged engine event which gets expensive.
No one had a solution for me to prevent pin loosening on oem pistons but maybe coating them will reduce temps and resulting pin loosening?

Ceril

[xixp]

Ive used pro x with good results, may it be depends on riding style and oil quality..?

[Robsauto2]

[QUOTE=xixp;2594348]Ive used pro x with good results, may it be depends on riding style and oil quality..?[/Q

Amsoil Dominator. I was amazed at how clean the top end was, very impressed with this oil. The cylinders look almost new.