Cannot seem to find anything other than standard and prices insane.

Any pistons and rings from other models that work with ‘74 dt360?

I think Enduronut has the market pretty much cornered on the pistons for DT 360’s but he has all over sizes at least he did a couple months ago when I got mine from him. Sorry to see yours burned up on you, has me a little worried about mine but mine is putting out plenty of smoke and even drooling a bit so I think it’s lubing okay and not getting too hot.

Like Dave said, Enduronut has original Yamaha pistons and rings and if you need seals he has the original Yamaha crank seals too. I got all of those things from him about a month ago. The pistons and rings do show up on ebay now and then but most are overpriced and there's also the real possibility of getting the wrong parts. Appears that some of the ebay sellers don't even know what they're selling and often have incorrect part numbers.

The closest fit I've come up with is a Honda FL350 piston made by Wiseco. Requires a spacer under the cylinder but dome height is the same, ring pegs are in the right spot, 18mm wristpin just like the DT and it clears the crank at BDC. It is forged and comes with modern rings, far better in my opinion than the old Dykes rings Yamaha used. It also has a solid intake skirt with no ports or windows which gives you the option of a power ported intake, with the piston port timing aimed at top end power and the reeds filling in low-mid. Lastly, this cleans up your intake signal which improves carburetion over the stock piston. Add some epoxy filler to the transfers in addition to that and you'll really be cooking.

I think I used 4mm aluminum and fine tuned the deck height with base gaskets. I think 3/16" would be close to ideal, its about 4.75mm. If I make another one I'll use the 3/16". You can get aluminum sheets in that thickness on ebay for about $30.

Thanks all
I sent enduronut a PM
Mine was lubing good too, issue likely gas cap vent, which I will confirm tonight
Situation totally sucks but in big scheme of life this is insignificant

I would be nice if Wiseco made 360 pistons, same problem with the SC500, didn’t make enough to warrant production. One reason I sold my DT360, plus wife retired and thinning the herd. I thought about doing a DT250/360 with a MX250 engine and a heavy flywheel. 250 pistons are readily available.

Wiseco will make anything you want. Just need to order a minimum of a dozen or so.

With the popularity of the DT360 lately, might be a worthwhile investment for someone to have Wiseco make a run... problem is that a lot of people want to pay 1970's prices for parts and a new piston kit will probably be around $200.

I see that Wossner is making pistons for some of the older models now too... they might be willing to make DT360 pistons if someone reached out. I met a US Wossner distributor a couple years ago... seems like a nice guy... based in So Cal somewhere.

I got a quote from Wiseco in 2019 of $1750 for a batch of twelve. If you could get three in each size in one batch it wouldn't be a bad deal. Having to get twelve of each size would be a big investment.

CMSNL appear to have piston and rings in 1st and 4th oversizes but, again, prices are daft. Also, I don't know what postage from mainland Europe to US would be and whether or not you have to pay taxes at your end.

I also bumped into this situation when rebuilding my 360A. The 360A is kind of a mongrel, being a one-year only bike. I'm sure Wiseco did not see a need at that point in time. I searched very hard during the rebuild, could only fine OEM (Enduronut supplied and bored the cylinder ).

There does seem to be a resurgence of them lately. I think it would take a very committed enthusiast to commission a run of pistons (and rings??) to suit, plus, how could you determine exactly which sizes to do? Probably very few standard size pistons needed at this point I would think. Maybe more in the larger O/S, even a 5th & 6th if that were even feasible, depending on liner and viability.