70 mm Oversize Piston For My TW
Close
    
    

View Poll Results: Will you take the risk to use a Chinese made piston on your TW

Voters
22. This poll is closed
  • YES

    5 22.73%
  • NO

    17 77.27%
Page 1 of 3 123 LastLast
Results 1 to 10 of 21
Like Tree54Likes

Thread: 70 mm Oversize Piston For My TW

  1. #1
    Senior Member Cornelis's Avatar
    Join Date
    Mar 2015
    Location
    Centurion, South Africa
    Posts
    589

    70 mm Oversize Piston For My TW

    My bike is starting to use more and more oil so I'm busy making plans for an engine rebuild before the end of the year

    New OEM Yamaha Piston and Ring Set will cost me over $100 but then I saw an offer on aliexpress.com for only $ 31 so I decided to follow the example of our friend elime and I ordered it

    The set is manufactured in China but just hold on before you get worried about the quality this looks like a reputable company, also take into consideration that even BMW engines are being manufactured in China for the past 10 years. Go to http://www.chinamotorrider.com to read the article

    Hopefully the piston will not end up melting in the cylinder in the middle of nowhere and is only scheduled to arrive end of next month and as soon as I installed it I will report back.

    Go to 70mm-Motorcycle-Piston-Kit-Pin-Rings-Clips-Set-for-YAMAHA-TW200 to have a look at the offer

    littletommy and Ken like this.
    1990 Yamaha TW200Hidden Content _____________ Come to Me, all you who are weary and burdened, and I will give you rest. - Matthew 11:28
    Hidden Content

  2. #2
    Senior Member elime's Avatar
    Join Date
    Jul 2010
    Location
    San Jose, CA
    Posts
    6,958
    I bought two extra cylinders off ebay for really cheap and if I hadn't been procrastinating I would have already honed one out for the 70mm cheap Chinese piston I bought and then tried to talk TW-Brian into using it on "Little Monster".

    I have been using cheap Chinese high speed and pilot jets and I think they are great! I bet they are production overrun for Yamaha and being dumped on the open market.
    Cornelis and Ken like this.
    Long live the internal combustion engine!

  3. #3
    Senior Member Cornelis's Avatar
    Join Date
    Mar 2015
    Location
    Centurion, South Africa
    Posts
    589
    Great stuff bro, I really believe Yamaha is exploiting us with their sky-high OEM prices.
    Peterb, Ken and WECSOG like this.
    1990 Yamaha TW200Hidden Content _____________ Come to Me, all you who are weary and burdened, and I will give you rest. - Matthew 11:28
    Hidden Content

  4. Remove Advertisements
    TW200Forum.com
    Advertisements
     

  5. #4
    Senior Member Mattwings's Avatar
    Join Date
    Mar 2015
    Location
    Northville, MI
    Posts
    779
    For a piston, I would more likley pay a premium for a Weisco or some other esoteric aftermarket rather than Chinese. It is just such a small expenditure vs. time, if you have to rebuild or teardown a motor early because of an inferior part. I am pretty frugal with lots of parts, finding a good balance of cost, service life and performance. Things like handgaurds, bearings, bars, tubes, cables etc. When it comes to engine internals, I always try and find the best, not even he best for the $. But, that is just me, probably will be great!
    2002 TW200 "The Punisher"
    1998 DR350r
    1996 KDX 200
    Riding in and around the great state of Michigan (usually)

  6. #5
    Senior Member Fred's Avatar
    Join Date
    Dec 2011
    Location
    Turtle Wrangling the Sierras
    Posts
    18,592
    Since Yamaha doesn’t really manufacture anything anymore, but is more of an assembler of parts submitted by jobbers it can be hard to evaluate the pedigree of any part source from year to year.. Witness the numerous quote “OEM” faulty oil filters some jobber submitted that Yamaha’s quality control didn’t detect.
    2003 TW200 "Betty Boop"
    2006 TW200 "Nibbler", a.k.a. “Mr.Gizmo"
    Hidden Content All Things Considered I’ld Rather Be Motorcycling

  7. #6
    Senior Member CS1983's Avatar
    Join Date
    Aug 2011
    Location
    Tulsa, OK
    Posts
    634
    My problem with it wouldn't be it's Chinese. It would be that if I'm doing a piston job, I want to be buying the best thing I can since it's a rather integral part. However, what my understanding of Chinese manufacturing is, they basically bought a bunch of nice machining tools off of Japan and others. Their product could certainly be just as good as anything else. I dunno. Glad you want to be the guinea pig and not me
    Cornelis, Tweaker and Ken like this.
    Hidden Content Hidden Content

    "I thought the slowest bike i have ever owned was going to kill me." - Hidden Content

    The John Birch Society is too Liberal.

  8. #7
    Senior Member Fred's Avatar
    Join Date
    Dec 2011
    Location
    Turtle Wrangling the Sierras
    Posts
    18,592
    All I know is I like and trust my Wiseco piston. Gave me peace of mind yesterday when running wide open at summer temperatures above 9,000 ft with a slightly reduced oil level. Sonora Pass is an awesome twisty steep (25% grades in places) places to romp around on a TW. All the other bikes I saw had a liter more displacement than lil’ Betty Boop.
    Cornelis, PlacerLode, Ken and 1 others like this.
    2003 TW200 "Betty Boop"
    2006 TW200 "Nibbler", a.k.a. “Mr.Gizmo"
    Hidden Content All Things Considered I’ld Rather Be Motorcycling

  9. #8
    Senior Member Mattwings's Avatar
    Join Date
    Mar 2015
    Location
    Northville, MI
    Posts
    779
    Chinese stuff is often good quality, but some of the high end manufacturing is still a step or two below US, European or Japanese quality. A friend of mine runs some very high end manufacturing internationally, including in China, and they are not able to produce the most advanced machined parts there (they have tried to steal the designs for several years, just can't perfect the copies). Pistons are not that complicated, they can likely make decent copies.
    Cornelis and Ken like this.
    2002 TW200 "The Punisher"
    1998 DR350r
    1996 KDX 200
    Riding in and around the great state of Michigan (usually)

  10. #9
    Senior Member elime's Avatar
    Join Date
    Jul 2010
    Location
    San Jose, CA
    Posts
    6,958
    The Wiseco 4312 70mm piston is supposed to be used with a 58mm stroke crankshaft and when it is it yields 10.25 compression ration. Used with the TW 55.7mm crankshaft the compression ratio drops to 9.9 about a .3 drop. Ditto for the cheap Chinese piston only that it probably starts with a 9.5 compression ration and would drop to around 9.2 . This drop isn't very much in term of performance as the increase in performance is in the increase in displacement.

    The piston in Betty Boop is a Wiseco 4292 and is supposed to be used with a 55.7mm crankshaft and it has an honest 10.25 : 1 compression ration. Unfortunately the largest 4292 Wiseco makes is a 68mm. A 69mm and 70mm would sure be nice.

    Wiseco piston is forged and the cheap Chinese is cast. Forged is stronger than cast but the TW comes stock with a cast piston which I bet is in 98.5% of the TW's on this forum and how often do you hear of piston failure? My conclusion is the cast pistons are pretty good. (True confession: I have Wiseco's is both of my TW's -- a 68mm and a 70mm.)

    I bet the cheap Chinese cast piston would work out just fine. For $30 including rings and wrist pin is a steal. To bad my CCCP (Cheap Chinese Cast Piston) didn't make it into Little Monster. I think it would have been a good test as to its quality.
    Cornelis and Ken like this.
    Long live the internal combustion engine!

  11. #10
    Senior Member elime's Avatar
    Join Date
    Jul 2010
    Location
    San Jose, CA
    Posts
    6,958
    Just curious, of those that voted no how many of you have held one of these pistons in your hand ?

    P1080031.JPGP1080032.JPG
    Cornelis, Ken and WECSOG like this.
    Long live the internal combustion engine!

Page 1 of 3 123 LastLast

Sponosred Links

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Similar Threads

  1. Oversize Cylinders
    By elime in forum Technical Help
    Replies: 6
    Last Post: 05-21-2017, 11:58 PM
  2. Honing for oversize piston
    By elime in forum Technical Help
    Replies: 19
    Last Post: 08-31-2015, 10:14 AM
  3. 1mm oversize exhaust valve on ebay
    By tumbleweed in forum TW200 Classifieds
    Replies: 9
    Last Post: 03-01-2015, 01:30 PM
  4. new oversize footpegs wont install, helpp
    By Drapes in forum General Discussion
    Replies: 6
    Last Post: 05-21-2012, 11:57 AM
  5. Clarkes oversize fuel tank?
    By skeetsoffroad in forum General Discussion
    Replies: 2
    Last Post: 01-05-2012, 08:36 PM