flyday58 Posted September 18, 2012 Author Posted September 18, 2012 Wow, wow, and more wow, you guys are the bomb! Lots of good info, anyone else drilled oil holes in their pistons? Do OEM units have these, or are they correct from Yamaha in some other way? Don't know the piston brand, OGOABINTHEUSA (he is 74)bought it from his supplier to save me some $$/££, will post a pic tomorrow. Size is laser-etched on the dome. It was dark when this second seize occurred so I couldn't see the oil line going to the cylinder. But shortly after installing the clear line a few months back I had an issue at high revs where the oil appeared to get sucked out of the line. I asked but no one seemed to think this was possible, so maybe I had air in the system somehow. I will check this also. I live in Missississississississippippippippippi, where it's been my experience that, if you wasn't born here then you ain't one of us. I have a damn hard time getting things done that my neighbor has people fighting over and supplying their own beer (yes, we have BOTH kinds of beer here, Bud AND Bud Light ). The guy who did my rebore was very hard to find, but he has a well-equipped shop with devices and machines dating from the late Cretaceous and I'm fairly sure his work is fine, but I will have the cylinder checked. Garrowby Hill. Anywhere near the Hammersmith flyover? I know where THAT is.
Moderator Airhead Posted September 19, 2012 Moderator Posted September 19, 2012 Thats the wrong piston by the way, it looks like one from the twinshock bike
nayruf Posted September 19, 2012 Posted September 19, 2012 Hi I have been watching this post, having looked at the latest pictures of your piston all I can say is the 2 ports in your piston look smaller than the ports on the piston in my bike and I thought they shared the same pistons, the ports in my piston are bigger and are more of a square shape
dt502001 Posted September 19, 2012 Posted September 19, 2012 I know whats over heating right now Flyday he is going to be pissed at the daft bugger who got him the wrong piston. What type of piston is that nayruf? it's a beauty with the relife cut in for extra lubeing/weight saving.Just like most newer bikes use.
Moderator Airhead Posted September 19, 2012 Moderator Posted September 19, 2012 I would go as far as to say that yours is wrong also nayruf, yours looks like a 175MX piston...perhaps you two should do a swap
dt502001 Posted September 19, 2012 Posted September 19, 2012 I guess everone was right on this one. lack of lube -- to small of ports over heating---lack of lube poor bore job-- lack of matching the piston port to clyinder to ports.
nayruf Posted September 19, 2012 Posted September 19, 2012 Lol I cannot show a picture of the piston that is in my bike ( as it is in my bike) but I know that the piston currently running has elongated ports and is recessed at the sides as shown in the picture, As the current piston has done well over 3000 miles and the bike will show an indicated 70 mph I am quite confident that it would of gone bang by now if it was drastically wrong, but I do appreciate any concerns shown, I do also have the previous piston and that is also has the same characteristics The only reason this piston was changed was because a crank brg broke up and part of the roller cage had slid up the side of the piston wall, I just wanted to show that I figure that Flyday has probably got a piston for a 5 port early DT/CT bike
Moderator Airhead Posted September 19, 2012 Moderator Posted September 19, 2012 Lol I cannot show a picture of the piston that is in my bike ( as it is in my bike) but I know that the piston currently running has elongated ports and is recessed at the sides as shown in the picture, As the current piston has done well over 3000 miles and the bike will show an indicated 70 mph I am quite confident that it would of gone bang by now if it was drastically wrong, but I do appreciate any concerns shown, I do also have the previous piston and that is also has the same characteristics The only reason this piston was changed was because a crank brg broke up and part of the roller cage had slid up the side of the piston wall, I just wanted to show that I figure that Flyday has probably got a piston for a 5 port early DT/CT bike yeah I thought you'd laugh at that...however I thought all the twinshocks had the rounded intakes in the piston because the pistons are different part# and the model guide shows it to be so...Honest guvnor, I dont make stuff up
nayruf Posted September 19, 2012 Posted September 19, 2012 yeah I thought you'd laugh at that...however I thought all the twinshocks had the rounded intakes in the piston because the pistons are different part# and the model guide shows it to be so...Honest guvnor, I dont make stuff up Please don't get me wrong, I am not laughing at anyone as such, I am thankful for any input and always appreciate any advice,
Moderator Airhead Posted September 19, 2012 Moderator Posted September 19, 2012 thats OK nayruf , this is what I meant, now this is the piston for a DT175C...clearly the holes arent as long as the 175MX...I know your bike runs well and I'm not suggesting for one minute (despite my little joke) that you shoud change it but just thought I'd point it out to you...food for thought as it were For Twinshock http://www.ebay.com/...6-/350456956387 and for DT175MX http://www.ebay.com/itm/Yamaha-DT175-MX175-2n5-11635-00-PISTON-2n5-11610-10-ring-0-25-NOS-OEM-NEW-/370643961150?pt=Motorcycles_Parts_Accessories&hash=item564c1a053e&vxp=mtr
flyday58 Posted September 19, 2012 Author Posted September 19, 2012 Damn dammit damitol2hell. This was the original. Crap in a cup.
Moderator Airhead Posted September 19, 2012 Moderator Posted September 19, 2012 Aye thats the one Richard, either 2A7 or 2N5 (Both the same)
flyday58 Posted September 19, 2012 Author Posted September 19, 2012 YAMAHA DT175 DT175MX DT 175 0.50 PISTON KIT Junk or a good product?
Moderator Airhead Posted September 19, 2012 Moderator Posted September 19, 2012 I always use Yamaha or a good Japanese equivalent, these are more likely Chinese/Taiwan copies but thats why they're so cheap Having said that..Because it's so hard to come by the good ones I wouldnt have any hesitation myself It doesnt mean that it was the cause of the heat seize though...up the jet as well if it will run right
flyday58 Posted September 19, 2012 Author Posted September 19, 2012 Okay. Now we wait for parts. Maybe by spring...
oldbikerehab Posted September 20, 2012 Posted September 20, 2012 fwiw, I put together all the parts in the piston kit you linked, but OEM and including a new bearing for $108 delivered. Looks like it would be about $112 for you so something went up a bit, but fair enough if you don't mind throwing in an extra 20 bucks for OEM. Shipped from U.S. (Georgia, I think) in a week + a few days.
oldbikerehab Posted September 20, 2012 Posted September 20, 2012 Link to 1978 DT175E piston parts I mentioned. http://www.powersportsplus.com/parts/search/Yamaha/Motorcycle/1978/DT175E/CRANK+-+PISTON/parts.html#uloc8
flyday58 Posted September 20, 2012 Author Posted September 20, 2012 Thanks OBRH, I use Yamaha Sports Plaza in Oregon altho I use your guys, too. I think all of them get some of their parts from Japan as it can take inordinate amounts of time to get an order filled. Your site sometimes skips part numbers if they're no longer available, and I really need the cross-ref ability since I'm working on 3 diff bikes. I guess I could look them up on my site and order on yours to save a few $$ but I'm too lazy... I just wonder why some OEM pistons on fleabay are 150 bucks but the parts houses have them for 60 to 70. Just hope the piston I ordered are genuine OEM and not Chinese knock-offs. Anyone remember when "Made in Japan" meant "junk"?
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