Anyone know who sells these engines ? My son bought a used sts .21 at the track Saturday after his race engine finally died. It says sts on the head & some other stuff in what looks like japanese . He only paid 60 dollars mainly to pay for the v-spec carb. it had. Upon racing he is impressed . That engine is a screamer & it actually ran 9 mins 30 secs before running out . I can't believe it. Anyway the bearings feel a little rough so we want to replace them. Thanks for your help guys.

I don't know personally, but it's a safe bet that quite a few engines run the same size bearings in them.

If you have a caliper, take the bearings out and measure them. Then you should easily be able to find replacement ones.

Good luck.

Just found this as well: http://www.rcuniverse.com/forum/m_52...tm.htm#7618846

I have had 5 STS engines and if I remember correctly the rear bearing is a strange size. Here is the only place I know of in the US that still carries STS engine and parts.
http://nitrocountryrc.com/-c-45_46.html

I have one STS D21B with well over 5 gallons on it that I just put new bearings and a rod in it still going strong. What STS engine do you have? I have run 10 minuet qualifiers on it and never pitted. If you have problems on getting the rear bearing PM me. I live in Macon.

Here is the bearing sizes and there are a lot better bearings out there then the stock STS bearing.
Front Bearing #607 (7mm X 19mm X 6mm)
.21-.30 Main Bearing #2514 (14mm X 25mm X 6mm)

Here is STS manufacturers web site.
http://www.stsrc.com.tw/

I use to be sponsored by a company that use to sell STS engines in the US. He closed his business. In the last 8 months have been running large scale and still have 4 STS engines. One D21B new in the box. I think the STS D21B is the best budget engine out there. VERY STRONG! If I can help let me know.

Thanks for the replies guys. You've been very helpful.

rc-mall on ebay has them and all the parts, i personally would not spend the time or money re-building one. just buy a new one, takes about 3 weeks though. i'll be getting another soon for a club motor, can't beat them for $130 shipped. no carb issues, bearing issues or anything. just seal them up, break them in and run them till they die. its the buggy version of the 3.3.

There are some STS parts here (including bearings), mostly big block, though some of the parts are the same across multiple engines.

STS recommends doing the front bearing every gallon (maybe a tad overkill in my book) but a bad front will rapidly take other things with it. That seems to be the failure mode when you find a bad main, snapped crank pin/rod, the front loosens up and the crank starts wandering a bit accelerating wear elsewhere.

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