Piston Assembly

[ncbrock]

When I was taking my engine apart, and ordering some new circlips I noticed a part on the diagram that wasnt there when I was taking the piston off. Its a little washer that goes between the pin and the circlips. Im positive it wasnt even on there, my engine has been running great all season long, so I didnt even bother to get new ones. What is your thought on this?

SKU: 90201-20M04-00
WASHER, PLATE

 

[SurferSmurf]

never seen any in my motor. this is new to me.

 

[junkyardj]

you mean a washer on both sides of the wrist pin bearing?

 

[Waternut]

I've ripped into a lot of kawi and SJ motors... Never seen a washer on the wrist pin. I've always seen 1 wrist pin, 1 wrist pin bearing, 1 piston, and 2 circlips.

 

[Matt_E]

They're called thrust washers. 701's had them, 650's did not.
If you want to run without them, I'd get the 650 Yamaha bearings which are slightly wider.

 

[ncbrock]

hmm well im 100% positive I dont have a 650, maybe I already have the 650 bearings?

 

[Yami-Rider]

I have rebuild 3 different 701's and they all had thrust washer. I feel Yamaha must of put them in there for a reason, so run them.

 

[Crab]

Engine builders will tell you not to run them, get the wider oem bearings, its just another thing to fail.

 

[luker]

i think the kawi 750 are wider as well

 

[SUPERTUNE]

They're called thrust washers. 701's had them, 650's did not.
If you want to run without them, I'd get the 650 Yamaha bearings which are slightly wider.

Bingo! Matt is right.
The last 2 digits of the OEM part # for 701 is U2, (short bearing)
Last 2 digits for the 650 bearing is U3. (longer bearing)
OR use the Wiseco # 1023 for the Kawasaki 750 small pin engine. (recommended)

 

[badboyr6]

i found them in my 701 when i took it apart, so i would run them if they were there from factory..

 

[ncbrock]

I guess ill go ahead and order them, if I use them I use them if I dont I dont. I dont know if I have the larger bearings or not.

 

[SUPERTUNE]

Do you have any calipers to measure them for total length? If so post it here and I'll give you an answer and/or I'll post the size tomorrow when I'm at the shop...
Chuck

 

[ncbrock]

Nope! All i have is a tape measure

 

[orangefinger]

measurements might not be 100% right but you can see that there is a size difference