wrist pin question

[accbr]

Putting another 701 motor together. I already have some 62t wrist pins and 81mm pistons. The last motor I assembled I just used the 6m6 wrist pins so I didn't have to use the thrust washers. I was looking at Riva's part finder page, and one shows washers next to the circlips. The other show washers next to the wrist pin bearings. How do I know which one I need? I thought all superjet topends where the same. The part numbers for the wrist pin bearing are the same for all years.


http://216.37.204.203/yamaha_OEM/YamahaPWC.asp?Type=13&A=100&B=3

http://216.37.204.203/yamaha_OEM/YamahaPWC.asp?Type=13&A=64&B=3

 

[Matt_E]

Quick OT question....why do you not need the thrust washers with 650 Wrist pins? :dunno:

Those wrist pins should be identical between motors, right?

 

[accbr]

They're longer, so you just use circlips. That's what I've read anyway. I couldn't get washers AND circlips in there.

I'm talking about the washers next to the circlips. Maybe those aren't called thrust washers, but you don't use them on a 650.

http://216.37.204.203/yamaha_OEM/YamahaPWC.asp?Type=13&A=26&B=4

 

[Matt_E]

Wait a minute.

Are you saying 650 Yamaha Wrist pins are longer than 701/760 wrist pins?
I think you may be talking about Kawasaki 650 wrist pin bearings, which are longer than stock Yamaha bearings, negating the need for the washers.
EDIT: Bah....I looked. Indeed, 650's did not use the washers. However, even with the newer wrist pins, just use the Kawa 650 bearings and you don't have to use washers.

Now, your two links to Riva simply shows the thrust washers in a different location on the drawing. The part number is identical.

 

[Frosty]

i always put the washer on the piston pin, between the cylindrical bearing and the inside of the piston - one on each side of the bearing.

the picture on the parts finder is not a very good depiction of where they go

 

[accbr]

Yep, 650 wrist pins are different than 701 wrist pins. Kawi bearings must be what I was thinking. The Riva page was throwing me off, because it was differnet for a 98 and 03. In the drawings one has the washer by the circlip (98), and the other has a washer by the bearings(03). I guess since I already have the 62t wrist pins I'll just get the washers next to the circlips, and buy some Kawi bearings.

Now I can't remember what I did with the 701 I'm running now, but I've used it all summer.

 

[Matt_E]

I guess since I already have the 62t wrist pins I'll just get the washers next to the circlips, and buy some Kawi bearings.

I might be wrong...but it is my understanding that if you're running the Kawi bearings, you do not need the washers.

 

[accbr]

I think you're right. I was thinking I still needed one by the circlip to keep the pin from sliding back and forth a little.

 

[Matt_E]

You won't be able to fit washers on the pin with the Kawi bearing....and there is no other place for the washers.

 

[accbr]

I got it now. The two different pics were confusing me. It's been a long week. Thanks.

 

[tomski]

You need to run the yamaha 650 wrist pin bearings. These are 25mm; 701 are 24mm.

Kawi 650? Where did you come up with this?

 

[Matt_E]

They work on Yamaha topends and eliminate the need for thrust washers.

 

[tomski]

650 Yam 20x25x25

701 yam 20x25x24

650 kawi 18x22x24 no way

750 kawi sx 20x25x25 same

650 yamaha or 750 sx kawi bearings need to be used

 

[#ZERO]

I've found that a 701 Pro-X wrist pin weighs 75.8 grams and is 19.99mm by 65.70mm

A 701 Wiseco wrist pin weighs 83.8 grams and is 19.99mm by 60.04mm.

Also you can turn down the Pro-X wrist pins to 60.04mm and they will weigh about 67 grams for use with the Wiseco pistons.

 

[tomski]

great facts!

I've found that a 701 Pro-X wrist pin weighs 75.8 grams and is 19.99mm by 65.70mm

A 701 Wiseco wrist pin weighs 83.8 grams and is 19.99mm by 60.04mm.

Also you can turn down the Pro-X wrist pins to 60.04mm and they will weigh about 67 grams for use with the Wiseco pistons.

 

[Matt_E]

650 Yam 20x25x25

701 yam 20x25x24

650 kawi 18x22x24 no way

750 kawi sx 20x25x25 same

650 yamaha or 750 sx kawi bearings need to be used

Thanks. :bigok:

It was Kawi 750 bearings I was thinking of.

 

[WatrLogd]

Not to bring up an old thread but here's a newb like question: we have a guy out here running wiseco wrist pins (shorter) inside prox pistons. We pulled his topend apart, zero wear lines in either and still smooth as silk. Made me nervous but what are the dangers other than the pin slides back and forth againts the circlips? Sounds odd and a grenade waiting to happen but does anyone else do this?

 

[JetManiac]

Not to bring up an old thread but here's a newb like question: we have a guy out here running wiseco wrist pins (shorter) inside prox pistons. We pulled his topend apart, zero wear lines in either and still smooth as silk. Made me nervous but what are the dangers other than the pin slides back and forth againts the circlips? Sounds odd and a grenade waiting to happen but does anyone else do this?

Why would you do this? Prox pistons include a new wrist pin. Sounds like asking for issues.

 

[WatrLogd]

Why would you do this? Prox pistons include a new wrist pin. Sounds like asking for issues.

My feelings exactly, but he's running them aside from advice against it. When it blows we'll see why.