I was told SHO is a throw away motor if it burns up, is this true? Was thinking about buying a SHO but if I don't buy brand new and take a chance on a motor and it blows that's 10 grand for new block assembly. So should've just bought new. I know it's all a gamble buying a used motor but why can't the SHO can't be rebuilt unless I'm being told wrong.
Thanks
I believe it can be rebuilt just depends on what's damaged and a new block maybe less costly than a rebuild.
Like virtually anything it can be rebuilt. It is just a matter of cost versus benefit. A hundred dollar repair is one thing, a ten thousand dollar repair is altogether different.
I suspect that what you have heard is internet rumor because the block uses flame sprayed cylinder wall liners. It would take a machine shop/motor rebuilder that is familiar with that type of construction, and who has the necessary equipment, to perform a rebuild if the cylinder walls were damaged. The same applies to some automobile motors.
yamaha says it can't be rebuilt. challenge accepted
2004 Ranger 521vx Yamaha 250 SHO
Friend of mine is a Yamaha mechanic for 20 years and told me that. Has me scratching my head and wondering if I should keep my HPDI. No issues with HPDI just was thinking about upgrading.
The block starts life as a cast aluminum assembly. The cylinders are bored to a particular size and finish. The cylinders are then lined using a flame spray process. Then honed to a particular size and finish.
What is to prevent a machine shop from removing the existing liner and then re-flame spraying a new liner in place?
The flame spray process has been around for years and years, decades and decades actually. Ford started using it in automobiles. Yamaha adapted Ford's processes and started using it in the SHO and Offshore motors. Acting like it is something special only they could do.
Now Yamaha does not recommend a rebuild, that it true. But Yamaha not recommending it does not mean that it cannot be done. Actually, I don't see anything in the SM that says not to rebuild a block. It simply gives the correct dimensions for the cylinders. If they are met, does Yamaha really care? Why would they? Think that folks in the rest of the world are throwing away a rebuildable block just to buy a new one?
Now would Yamaha prefer that someone buy a new ten thousand dollar block from Yamaha instead of repairing a damaged block? You betcha!
Click on the video button to see the process in action. Pretty cool IMO.
http://flame-spray.com/
Last edited by jethro1; 03-28-2017 at 08:48 AM.
There is no liner
Cylinders are plasma fixed right to the block no rebuilding
Jasper engines is rebuilding them. Flame Spray is expensive but can be done.
There is a liner. A torch (plasma arc in Yamaha's case) is used to melt metal that is then flame sprayed onto the aluminum cylinder wall. The metal that is blown onto the cylinder wall becomes the liner.
The old liner can be stripped off and then a new liner installed.
This is nothing new. The technology has been around for years and years. Decades and decades. Just only used in a Yamaha outboard motor with the introduction of the SHO and Offshore models. Yamaha's marketing men just picked up on it and used it like it is the greatest thing since sliced bread. That is what marketing men do.
It is a bit perplexing reading folks saying that stuff cannot be done while at the very same time folks are doing it.Originally Posted by hblancet
So it goes like this... sounds like it possibly can be done, however very few can do it and the cost maybe high.
Gonna take me all day with a mig welder jeeeez
2004 Ranger 521vx Yamaha 250 SHO
The flash video wouldn't play so I found a few others that explain the process.
Here is some more info. Illustration is from Yamaha literature where they tout the technology.
From my understanding Yamaha provided the motors (V6 & v8) that Ford used in the SHO's that used this technology. Ford and Yamaha are tied together through Ford owning 5% of Yamaha.
Last edited by davepjr71; 04-05-2017 at 11:11 AM.
HVOF dearly easy on ODs. IDs not so much and takes specialized equipment. Replacing chrome plating as wear surface several industries.
Wow...didn't know this. So Yamaha played a part in Ford SHO engines??
2012 Z521, Yamaha 250 SHO
SOLD-1998 Ranger 519DVS, Mercury 225 EFI
Semper Fi
Yep, in fact when we worked on them that is what we referred to them is a Yamaha. CJ
2002 X19 200HP OX66 HO Vmax,HPDI lower, it lives, thanks Hydro Tec.
Wow so the Ford SHO was a yamaha motor all along.. =/ made and supplied by yamaha. Interesting.
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