New Riva crankcase thrust surface repair kit

[Green Hulk]

This kit will be extremely beneficial to many people as some failures on the Yamaha 1.8L engines involve the crankshaft being pushed forward in the engine. This can be caused by a number of reasons. Some may include:

- drive coupler coming loose.
- The PTO transfer shaft coming loose.
- The nut on the end of the pump driveshaft coming loose.

These failures can push the crankshaft forward and damage the thrust plate area inside the engine block. As a result, the engine block is damaged and needs to be replaced. ($2800 retail for a new engine block)

Riva has developed a replacement bronze bushing (part# RY10040-TB-OIB125) that can be fitted by machining the damaged area of the engine block. This can save the engine block & dramatically reduce the cost of the repair. A qualified machinist should be able to handle this install without any issues.

Attached are some pictures to help you understand the purpose/fitment of this bushing.

The kit is available now for immediate shipping from this link in the forums online store

http://www.4-tecperformance.com/index.php?main_page=product_info&cPath=16_82_167&products_id=3180

[Doug78]

How they should have been built in the first place!!!

[Leendert]

Riva did mine when they did the work on my engine as a standard option.
Mine also doesn't quite look like that.

Jim did you see this?

[toxicgun]

We need that for seadoo motors

[Chupacobra]

Seadoos have a thrust bearing..

[big john]

this is a huge problems for SHO conversions as there are no pads on the inner bottom of the hull to help keep the motor from moving forward under heavy load, the coupler really doesn't keep the motor from moving, great idea RIVA

[Waterholics]

So is there anything we can do in the first place to stop this from happening? Also does the kit come with only one face? I damaged more than one face on my block when my crank walked.

[Nils888]

Nice fix. I have been using the thrust bearing from the Kawi Ultra to do the same job.

[big john]

So is there anything we can do in the first place to stop this from happening? Also does the kit come with only one face? I damaged more than one face on my block when my crank walked.

you could actually do this to both sides of the main bearing web and create a thrust washer forward and rearward

[rossnemo]

Ive had 2 fixed by having a bead laid on the scuff on the block and hand file fitting the bead to get crank end play to spec and works great, but this is better. More durable than aluminum for sure. How is the plate attached to the block Jerry? Cant tell from the pic.

[Leendert]

I think its held by the crank once its put in.

[thomaswester]

Very good work RIVA!

[bamf]

I think its held by the crank once its put in.

Correct, it is held in place once the crank is set in the block. It's also held in place when the other half of the block is bolted up. Also, when the block is machined, it creates a "pocket" that captures the bushing. In other words, it's not going anywhere.

[rossnemo]

Agreed, looks like this one cant fall out. Worked on several Mitsubishi Eclipse/Eagle Talon turbo cars years ago and they liked to drop the insert thrust bearing out, but it was a much smaller half circle thrust washer setup instead of a plate setup like this. Lots of engines to be saved with this fix. Great job Riva..

[hotbutta]

Anyone have a set for sale? I need ASAP.