flyday58

Is it tomorrow yet? How did it go?

There'll be an extensive list of suggestions shortly, but details are the key on this forum. Most knowledgeable peeps on the planet about Yams in general, DTs in particular. But we need details. Does the frame and engine serial number begin with '2A7'? That's correct for the '78 E model, anything else needs more research. Where did the bike come from? Was it running, a barn find, in a box? Sitting under a tarp for the last 20 years? We could use whatever history you have to help get you sorted. So you dropped some parts. Unless you stepped on the needle it should be fine. Is the clip still on it? Important as it will just stick in the nozzle without it. The slide will only go in one way, there's a plastic pin sticking out inside the barrel for a guide so as long as it's lined up, again you're safe. The carb off ebay, is it a new aftermarket or OEM? OLDBIKEREHAB and myself bought non-OEM and both of us found damaged o-rings on the idle air screw: Didn't think I would have to disassemble a 'new' carb. With problems I kept having I decided to go back with the Mikuni carb and I'm glad I did. I'm pretty sure OLDBIKEREHAB is still running his aftermarket unit without any problems. The problem I had that made me shove the DT in a corner of the shed for about 6 years was it wouldn't rev over 3000 rpm no matter what I did. I could putt around the yard but it absolutely refused to go over 3Gs. Long story short, the high speed coil in my magneto was bad. Once replaced she revved to the red-line no problems. Yours could be a fuel prob with the carb, air leaks (Airhead steered me and others to the crank seals), magneto issues, even a loose frame ground/ earth point. And as much as you want to get riding, we will all tell you the game has just started; grab a cold and settle in for the long haul. Better to sort things now than to have to redo things later. Witness my thread on heat seize, which turns out to be a wrong piston/too little oil/ too small main jet deal. I rushed so that's what I get. Hey, I'm American, what else could I do? Here's mine: Taken with my iPhone, pictures so life-like...if you need glasses!

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"?

Okay. Now we wait for parts. Maybe by spring...

YAMAHA DT175 DT175MX DT 175 0.50 PISTON KIT Junk or a good product?

Damn dammit damitol2hell. This was the original. Crap in a cup.

Won mo:

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.

Paul, what mm are the plugs so I can get the right gauge?

...think he's one of yours...

I think I will give that a try, thanks.

I installed a clear plastic oil line to keep an eye on my Yamalube, so far no probs. Also made sure the pump stroke is set correctly with the right shims. But I will take a closer look at the system while running; I did have an issue once where the engine seemed to suck the oil out at higher rpm but haven't seen it lately.

I've got a 150 main jet in there now. I was looking at installing a temp indicator but got side-tracked with all the issues with the CS5, now it's on my must-have list. So you don't see the paint as an issue? I will check timing when I get home, ran out of time last night. Send me a link to your temp gauge, if you would. I could go find the post but, ya know, lazy git.

Had another heat seize last night. Temps around 16*C, had gone about 12 miles, consistently around 4000 rpm. Going up a slight long incline, started to hear what sounded like the reeds flapping. When I realized what it was, I closed the throttle, clutched in and it immediately quit. After some testy moments with a friendly pit bull, I pushed it into a local power station lot, and after about 5 minutes gave the kicker a try. Was happy it turned over, so key on, kick again and it started normally. Rode gently the last 2 miles back home. I have already upgraded to bigger jets in both the main and pilot jets. I had the needle dropped all the way down but before the ride decided to lift it one notch. In addition, the day before when I rode it after about 2 months of sitting there was a distinct varnish odor. THAT got me really cos the gas was fresh in June. So I drained the tank and carb, raised the needle one notch, installed fresh gazolene and went for my ride. Having a memory like /your fave non-rememberer's name HERE/ and not having taken any pics of the motor during assembly, I decided to remove the head, cylinder, and piston when I got home. I had an idea the piston the guy who bored my cylinder bought for it didn't have the reed holes in the piston skirt. Well, I was wrong about that score, the holes are there. The piston showed minor scoring on both sides where the piston pin goes through, otherwise no damage, top shows no sign of beginning to hole. Now. Do I up-jet again? One thing I did which I'm thinking could be a part of the prob: I've read a lot about peoples' propensity for the powder-coating route. NO I DID NOT. But I did paint the cylinder and head with hi-temp paint. Same difference? Maybe preventing the heat from dissipating properly or even trapping some heat? The guy who bored the cylinder has been doing it for over 30 years, so I don't think it's a q of the rebore being bodged up. Cylinder looks nice and no burns on the piston sides. But the rod end bearing is bluish-purple and the pin has blue rings round it, which to me suggests the high temps. Took pics but they are currently on the other side of my "Japan door" so can't post them. So, what do y'all ?

Yup. Just wanted to make sure he was talking about the same part instead of spending money on the wrong thing.

My local Yamaha shop has to order parts like this, guess from Japan because it takes a while to get them. So I just use the online parts houses like the one in the link. I put in the link so you could point out what you're referring to as 'emulsion tube' so we can advise you a little better. There are multiple sizes to jets and pilots to help with tuning, and the same motor today needs a little tinkering with the jetting to run correctly on our ethanol-based gas. They gotta run rich or you risk 'holing' a piston.

Nevermind, found it. Whoever removed the armature I bought on ebay used vise-grips on the commutators to hold it. I cleaned up the damage but failed to notice one of the commutators is proud of the rest where the pliers were crimped on. It destroyed 2 of the brushes and knocked another so hard it was stuck fully retracted in its holder. No wonder it would not charge! Will have to deal with it when I come home. Have some brushes I can install after dressing the commutator segment and clean the carbon dust out of everything. Double !!

Having an issue where my charge light will not go out unless I force the cut-out relay into contact with a screwdriver. It will then charge normally with the light out as long as I don't idle. When the rpm drops back to idle the light comes back on and won't go out, and it is not charging. I have tried both regulators I have with the same result, so suspect the prob is not a regulator prob. Starter works fine with a full charge on the battery, all brushes in the stator are new or nearly new. Out of town to the U.K. for the next few days, so looking to get this sorted when I return home.

Go here to see your part:http://www.yamahasportsplaza.com/pages/OemParts#/Yamaha/DT3_-_1973/CARBURETOR/DT3_(1973_MOTORCYCLE)/CARBURETOR_(DT3_-_1973)

Must be touchy about it, shhhh!

Not Sacha's actual photo. We think. She says,anyway.

DT250F is a '79, DT3 is a '73; which do you have?

Welcome to the forum! Things are a little different across the Atlantic, they are actually courteous on their forums, and I've yet to run into the typical forum bullies so prevalent on U.S. sites. You know the type. I'd bet there ain't nothing you can't find out about your DT here, just super knowledgeable folks. I have a '78 DT175E and a '73 RT3 360, and they have been a huge help on different probs I've had. Lots better than thumpertalk. No question is considered dumb here. I've got good answers just looking at other posts before posting myself - lots of questions have already been answered several times somewhere on the forum. Some European bikes have different engine, frame, and model numbers (i.e., my DT175E is their DT175MX), but most of the parts are the same. Anyway, have a look around and enjoy! Richard

Kay, thx Noise.