TZR250 2MA piston rings

General forum on engines, transmissions, gearing and modifications to each

Moderator: rztom

Post Reply
Message
Author
podman
Posts: 504
Joined: Mon Nov 16, 2015 1:41 pm

TZR250 2MA piston rings

#1 Post by podman » Thu Sep 14, 2017 11:08 am

Ordered a set of std rings for my 500 and instead of 47x1161000 being delivered, ive had 2MAxxxxxx been sent instead, can these be used on my original pistons?

The bike has only covered around 900 miles so I do not wish to change the complete piston.

Thanks.

User avatar
Rick Lance
Posts: 366
Joined: Thu Nov 17, 2005 11:12 am
Location: Leicester, NC
Contact:

Re: TZR250 2MA piston rings

#2 Post by Rick Lance » Fri Sep 15, 2017 3:33 pm

Nope. They're incompatible. If you only have 900 miles on the original parts, why change them?
If I disagree with everyone, that doesn't make me right. If I take the side of only one, it doesn't end the fight. If my position's strong enough from exposure to the light, you may see things my way when we share the same highway.

silverstrom
- - - - -
- - - - -
Posts: 3236
Joined: Sat Feb 04, 2012 7:36 am

Re: TZR250 2MA piston rings

#3 Post by silverstrom » Fri Sep 15, 2017 4:04 pm

Why are they incompatible? Same bore size, same clearances, pistons are interchangeable.

podman
Posts: 504
Joined: Mon Nov 16, 2015 1:41 pm

Re: TZR250 2MA piston rings

#4 Post by podman » Fri Sep 15, 2017 4:40 pm

Thanks , id assumed by the difference in part numbers there must be a difference.

Ron57
- - - - -
- - - - -
Posts: 241
Joined: Sat Nov 12, 2011 10:50 pm
Location: Adelaide, South Australia

Re: TZR250 2MA piston rings

#5 Post by Ron57 » Fri Sep 15, 2017 6:53 pm

Hi think it is to do with the top locating pin different position
Cheers Ron.

User avatar
Speed Freak
- - - - -
- - - - -
Posts: 930
Joined: Sun Oct 28, 2012 6:38 pm
Location: Voitsberg, Austria

Re: TZR250 2MA piston rings

#6 Post by Speed Freak » Sun Sep 17, 2017 5:46 am

I`m wondering a bit why you get 2MA pats... The 47x1161000 (standard size) ring set is still available according to 2 different sources.

Here you have the comparison between TZR piston and ring set which is replacing the 47X parts and the standard front pistons:
viewtopic.php?f=3&t=11544&start=15" onclick="window.open(this.href);return false;
But the set doesn`t include 2MA rings, they are 3XC.

I think the standard TZR pistons had the same locating pin configuration as the RD500 but sometimes they were not correct in place and the rings started to rotate.
What you get as set is already the improved variant (2YK piston) which is also described in a document for all Yamaha dealers.
My bikes:
RD500 YPVS 1GE
RD350 YPVS 31K 1985
Honda CBR 1000 RR SC57
Yamaha R1 RN04

Ron57
- - - - -
- - - - -
Posts: 241
Joined: Sat Nov 12, 2011 10:50 pm
Location: Adelaide, South Australia

Re: TZR250 2MA piston rings

#7 Post by Ron57 » Sun Sep 17, 2017 6:51 am

Hi top piston is a 2ma bottom 47x. The left ring is a 3xc fits the 2ma the next ring fits the 47x,
so long as the top ring matches the bottom should be ok.
Cheers Ron
Image
Image

User avatar
Speed Freak
- - - - -
- - - - -
Posts: 930
Joined: Sun Oct 28, 2012 6:38 pm
Location: Voitsberg, Austria

Re: TZR250 2MA piston rings

#8 Post by Speed Freak » Sun Sep 17, 2017 11:38 am

The top ring is a "new style" 2YK piston which needs 3XC rings.

According to the parts manual factory piston was "1KT" with "2MA" rings.
The 1KT piston used the same locating pin type as the 47X piston => The 2MA rings could fit to the 47X piston.

Even more funny... The original 2MA rings (2MA-11610-00) are superseded by... 47x1161000 :smt003
You got it the other way around.

But if a part is superseded by another it means they are interchangeable.
My bikes:
RD500 YPVS 1GE
RD350 YPVS 31K 1985
Honda CBR 1000 RR SC57
Yamaha R1 RN04

User avatar
phildu31
Posts: 429
Joined: Tue Jul 19, 2011 7:49 pm
Location: Toulouse France

Re: TZR250 2MA piston rings

#9 Post by phildu31 » Sun Sep 17, 2017 1:42 pm

As Michael said, 2MA rings are superseded by 47X.
So they are fully compatible.

silverstrom
- - - - -
- - - - -
Posts: 3236
Joined: Sat Feb 04, 2012 7:36 am

Re: TZR250 2MA piston rings

#10 Post by silverstrom » Sun Sep 17, 2017 2:42 pm

Having rebuilt few TZR engines recently, I will confirm that.

https://www.cmsnl.com/products/47x11610 ... ma1161000/" onclick="window.open(this.href);return false;

Post Reply