Hot Rods Conn Rod + NEW needle Bearing too loose??

[TEManley]

Hello,

I have a 97 Suzuki RM125...

I did a top end rebuilt with new wiseco piston, ring, wrist pin and that.

after I put it together she was knocking bad...took it apart and the needle pin bearing was bad ( I could twist the Piston side to side....)

so..I ordered a new needle bearing...the rod is not scratched in ANY way.. looks perfect. but when i went to put the new Needle bearing in....ITS too Loose!! swoosh..right out the other side??!!

It IS an Aftermarket HOT ROD ( I did not do that-Previous owners must have done)

Did HOT RODs have a special bearing that I need to order from them?? the rod is perfect condition..NO scratches or nothing!! NO up down movement. just looks as though the bearing race failed...

but the replacement from part unlimited is too loose in the rod assembly...

all I can think is that being a aftermarket rod its gets a special bearing....?? I see a wiseco bearing that says 15mm x 19mm x 20mm.. is that an odd size...

Thanks for help!!

if Not Im gonna have to put new rod in!!!

 

[MX851]

I bought one of the hot rod crank assembalys for my 2002 YZ 85 last year when I seized the connecting rod bering and it came with a new needle bering. I think the bering is supposed to be a little on the loose side.

Thats just my best guess, but im not 100% sure. You might want to measure the original bering that was in the bike before you changed the piston and the new one, to see if the berings are the same. As far as the knock that you had that might be because the timing was set incorrectly when you but the motor back together.

 

[TEManley]

Well...I did some checking and I have found the specs for the HOt Rod conn rod...and...its the same as stock....

and take a "standard" 15mm x 19mm x 20mm pin bearing....

There is definately some play in the bearing and the con rod....Im just dont remember that being normal...

as far as timing...I didnt think that had to be adjusted at all when doing a top end?? I will have to look into how to time it...

but after running it..for a VERY short time...and taking back apart because of the "knocking" we discovered again that the piston can be twisted side to side about 1/2" and when I took the piston back out....the pin bearing FELL APART..telling me that that play.....destroyed it...

I guess all I can do is measure the bore on the con rod and ensure its at 19mm.....

Does anyone else remember their being some play on that bearing???

Thanks!!

 

[MX851]

Well im sorry to hear it didnt work out to well for youi but on my 85 it had play an the motor never blew up on me again.

 

[kxmike]

I bought one of the hot rod crank assembalys for my 2002 YZ 85 last year when I seized the connecting rod bering and it came with a new needle bering. I think the bering is supposed to be a little on the loose side.

Thats just my best guess, but im not 100% sure. You might want to measure the original bering that was in the bike before you changed the piston and the new one, to see if the berings are the same. As far as the knock that you had that might be because the timing was set incorrectly when you but the motor back together.

you dont have to time a 2stroke while doing a top end. the reed valve times itself with the piston.