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Will you take the risk to use a Chinese made piston on your TW

  • YES

    Votes: 5 22.7%
  • NO

    Votes: 17 77.3%

  • Total voters
    22
  • Poll closed .
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Discussion Starter #1
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:D, 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 :p 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

 

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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.
 

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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!
 

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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.
 

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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 :)
 

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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.
 

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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.
 

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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.
 

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Discussion Starter #11 (Edited)
That is a very good point elime, they cannot just shoot something down if they don't have a valid argument.

Take for example that the BMW 650 GS engine for the past 10 years and also the new BMW F800 GS engine are manufactured over there at the moment and there has been no negative reports about reliability issues as far as I know.
 

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Just curious, of those that voted no how many of you have held one of these pistons in your hand ?

View attachment 116665 View attachment 116673
Kind of a logical fallacy. I've never held a carcano rifle, but I still wouldn't buy one.

As I said in my reply, their product could be fine. They haven't proven that, though. We know other companies make good products. I'm not going to risk my time, labor, $, and perhaps even safety to something so integral. It's not a farkle. It's a piston.
 

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Lee Harvey Oswald bought one and you know the rest of the story.
To quote the old Willy Nelson lookalike at the flea market:

"I could shove a Carcano up my butt and pull the trigger and still not shoot myself."
 

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I would jump at the chance to buy a decent Carcano if the price was right. As for Chinese pistons, I have three bikes with Chinese engines and have been pleased with them.
 

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So far it's up in the air to me. Keep a Yamaha TW all oem? I replaced fork seals, after market that lasted 5 years, POC. I tried another after market fork seal, awaiting results. Stock fork seal had lasted right at 20 years. If the new aftermarket isn't sufficient guess where I'm buying the next one from. Stock piston and rings has 43000 miles on them now. In spec when disassembled. If I find out it wears out real quick now I'm going back to the car oil. I ran that for about 40000 in it. POC from Yamaha is the stock chain and I think the head bearings though I still haven't changed mine. I installed aftermarket shifter, hit dog not Yamaha fault. Aftermarket fork boots, foot pegs, handgrips all insignificant. I am still trying out the cheap Chinese cam. I need to compare the bike to a full stock to see if it improved or not.
 

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If trying the Chinese piston I would take careful measurements before ever trying it. My cheap Chinese cam needed machining. You may even want to heat both in an oven and compare expansion measurements. I would be careful. Let us know the results if you try it out.
 

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Discussion Starter #20 (Edited)
6000 miles report back

Its been 6 months and 6000 miles since I installed my Chinese made piston and rings and piston pin into my TW engine

I bought it at 30% of the price of an original Yamaha piston and rings set so I was curious to see whether the quality will hold up or not, it was an experiment for me.

If you read the previous posts you will see that I received a lot of negative feedback about my decision but unfortunately it looks like the naysayers were wrong, my bike starts up in the morning at the blip of the starter button and the engine is ticking over like a Swiss clock, never missing a beat, when I open up the throttle the bike is still pulling hard all the way into the red-line.

The engine is only using a small amount of oil, I couldn't measure precisely how much because my bike has been leaking oil from the gearbox and I was only able to fix that leak last week so from now on I will be able to monitor that, I'm sure it will be within the limits though



 
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