roffster Posted November 9, 2011 Share Posted November 9, 2011 I have had my 1979 DT250 MX in the garage and I am finally getting round to sorting it out. I cannot find anywhere in the manual where it tells you where to connect the autolube oil output to. I have a photo of my Carb here http://i1121.photobucket.com/albums/l503/roffster/Yamaha%20DT%20250%20MX/carb2.jpg But the obvious looking nipple on here is listed as a breather in the manual. Can anyone advise where the oil feed connects please? Link to comment Share on other sites More sharing options...
Moderator Airhead Posted November 9, 2011 Moderator Share Posted November 9, 2011 yes thats a breather roffster, a picture of the other side perhaps? Link to comment Share on other sites More sharing options...
Moderator Airhead Posted November 9, 2011 Moderator Share Posted November 9, 2011 err well that was my first thought but I found this picture which seems to suggest the one you think it may be, having said that oil spigots tend to have pointed rings around them to grip the pipe and breathers ate smooth with a bulbous end Have a poke through that spigot to make sure it is a clear passage into the carb venturi and away you go Link to comment Share on other sites More sharing options...
YPVS TONE Posted November 9, 2011 Share Posted November 9, 2011 Just found this on youtube. Looks like there should be an oil line spigot that fits into the hole just above the front float bowl screw on roffster's photo but doesn't show the spigot seperately on the parts breakdown of the carb. Not sure if one from an RD250 is the same http://www.pgmyamaha.com/shop/360-14333-00.html Link to comment Share on other sites More sharing options...
roffster Posted November 10, 2011 Author Share Posted November 10, 2011 oldgitonabike, thanks for the replies. I think your photo makes more sense, the video shows him connecting to something that isn't on my carb. The clutch cover and that side of the engine on mine was in bits but the carb hadn't been touched and was on the bike from when it last ran. There is no spigot in the end of the oil feed pipe which just looks like a push fit pipe and there is no spigot in the carb as can be seen from the photo, the oil pipe is about the right length to fit on the nipple you can see in the photo so I think this is probably the one. It was just that the diagram in the manual is misleading. I think I'll whip the carb off again and have a poke through as you suggest just to confirm. It is not helped by the fact the carb isn't quite right either. In my Haynes manual (the orange cover one) the carb in the MX supplement in the back shows the float as the one in the diagram you posted. But the float in mine is the same as the carb in the main body of the manual and has flat float lever tangs which sit under the float pins and not connected as one unit. Can't find any numbers on the carb either. But I do know it worked ok before the clutch came out so I don't want to mess too much with it. Link to comment Share on other sites More sharing options...
YPVS TONE Posted November 10, 2011 Share Posted November 10, 2011 If you have the carb off have a look at the inlet side of the carb just in front of the slide at the bottom .the 2 stroke oil usually gets injected here so maybe you can spray some carb or contact cleaner with the long extension nozzle fitted to the can down the hole and see where it comes out. What I would say is the spigot is missing from the carb where I originally said and is not shown on the parts list. The oil line fitted to the carb in og's photo looks too high to be the oil stub and I would say this is a carb vent. Was the bike running on premix when you got it ? Link to comment Share on other sites More sharing options...
roffster Posted November 10, 2011 Author Share Posted November 10, 2011 No the bike was running on the autolube system. Of course when I took the clutch cover off over 10 yrs ago I though I would remember everything!!! Schoolboy error! But I did leave the oil pump connected and in situ on the clutch cover so the only thing that was disconnected to let me move it out of the way was the oil feed to somewhere on the carburettor. I will take it off again and check both the nipple that might be a breather and the hole that may have a spigot missing and see what goes through to where. Do you have any idea where I might be able to find a carb number hidden? I thought I had a pretty good look when I cleaned the carb last weekend but couldn't see anything. Link to comment Share on other sites More sharing options...
YPVS TONE Posted November 10, 2011 Share Posted November 10, 2011 It is usually stamped on a small square section cast on the carb. In your original picture there is a small square section on the carb about halfway up on the side. Have a look there but they are usually quite small digits and faintly stamped. Does your frame number start 1M1? If so the carb number might be something like 1M1-00. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted November 10, 2011 Moderator Share Posted November 10, 2011 Having read again what tony said and looked at your photo, I too would lean toward the fact the spigot has actually gone missing from the hole, like I said a breather spigot will have no ridges around it and the one in the photo looks like a breather spigot! of course its possible that the picture I found on the web is also wrong eh? see if theres a hole right through the apparent hole heres my 175 carb for what its worth, you can clearly see the difference between the oil and breather spigots Link to comment Share on other sites More sharing options...
roffster Posted November 10, 2011 Author Share Posted November 10, 2011 Thanks for posting the photo, I am also leaning towards that conclusion. Is that Spigot a push fit item and do you think the RD spigot would fit? They both use a Mikuni VM28 carb I think (or is that too simplistic?) The frame and engine numbers begin 1R7 which i think denotes them as being from MX models. The more I look at my photo having seen your 175 carb the more it seems to make sense. That is the only hole on the carb around that area that isn't obviously blanked off. I can't wait to get it off again and have another look. I think I'll be in the garage with a headlamp tonight. I looked for the number on that little square moulding on the carb body, my eyes are not what they were and it was a bit dim but I couldn't see anything. I'll look again tonight. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted November 10, 2011 Moderator Share Posted November 10, 2011 mine arent either mate, sometimes a magnifiying glass is useful I havent any experience with the spigots but i would imagine they are a slight taper fit and tapped into place, if i might suggest you shove something into the RD spigot that is a good fit (a welding rod for example) this will support it from crush damage as you remove it, also wrap a piece of rubber around it to protect the ouside from the pliers...I reckon it should pull out easily really Link to comment Share on other sites More sharing options...
roffster Posted November 10, 2011 Author Share Posted November 10, 2011 Tony posted a link to a retailer that sells the RD oil injection elbow which is a push fit. Unfortunately they have a minimum order of £20 so I couldn't buy it to try it as it is only £5. I don't have an RD with one on. I'll look at it again and if it is the right place I'm sure there'll be a way to mackle it, or I'll have to ring and beg pgmyyamaha to sell me one despite their minimum order limit. Or I guess I could just plug the hole and run premix, seems a shame though. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted November 10, 2011 Moderator Share Posted November 10, 2011 Tony posted a link to a retailer that sells the RD oil injection elbow which is a push fit. Unfortunately they have a minimum order of £20 so I couldn't buy it to try it as it is only £5. I don't have an RD with one on. I'll look at it again and if it is the right place I'm sure there'll be a way to mackle it, or I'll have to ring and beg pgmyyamaha to sell me one despite their minimum order limit. Or I guess I could just plug the hole and run premix, seems a shame though. I have a spare carb body for 175, you verify the hole goes through to the inlet and i'll knock out the spigot and send it you Link to comment Share on other sites More sharing options...
roffster Posted November 10, 2011 Author Share Posted November 10, 2011 You're a gentleman! And a star, I'll whip it off tonight and get some piccies and have a look at that hole. Having seen your beautifully clean and shiny 175 carb you've also shamed me into getting the new dremel I bought yesterday out to have a go with the wire brush on the carb body Damn peer pressure! Is that how you did yours? I'd love to see some pictures of your bike if you have any posted anywhere/ Link to comment Share on other sites More sharing options...
Moderator Airhead Posted November 10, 2011 Moderator Share Posted November 10, 2011 You're a gentleman! And a star, I'll whip it off tonight and get some piccies and have a look at that hole. Having seen your beautifully clean and shiny 175 carb you've also shamed me into getting the new dremel I bought yesterday out to have a go with the wire brush on the carb body Damn peer pressure! Is that how you did yours? I'd love to see some pictures of your bike if you have any posted anywhere/ I didnt use wire brush..take care with that, needs to be quite soft or one of the brass ones. First was ultrasonic cleaning bath followed by plenty of gentle crud scraping in the nooks and crannies with a scratch brush (ebay), then plenty of polishing using T Cut rags and cotton buds, Heres mine if you can see it Link to comment Share on other sites More sharing options...
roffster Posted November 10, 2011 Author Share Posted November 10, 2011 That is very nice indeed! Did you do it all from scratch? I was going to use a brass brush, but after your words of caution I think I'll take it a bit slower. Did you get one of those smallish ultrasonic baths used mainly for jewellery? I was looking at them on fleabay and they are a fairly decent price. Here is a picture of mine from the weekend. 1st time in daylight for about 11 years, I've taken the tank and saddle off to make it easier to work on. But I think she is basically sound apart from the clutch centre boss and clutch plates I've got to replace. http://i1121.photobucket.com/albums/l503/roffster/Yamaha%20DT%20250%20MX/bike.jpg Link to comment Share on other sites More sharing options...
YPVS TONE Posted November 10, 2011 Share Posted November 10, 2011 Just found a couple of links that show the oil line going onto the spigot on the carb http://media.photobu..._2944Medium.jpg http://www.advrider.com/forums/showthread.php?t=347877 Link to comment Share on other sites More sharing options...
Moderator Airhead Posted November 10, 2011 Moderator Share Posted November 10, 2011 That is very nice indeed! Did you do it all from scratch? I was going to use a brass brush, but after your words of caution I think I'll take it a bit slower. Did you get one of those smallish ultrasonic baths used mainly for jewellery? I was looking at them on fleabay and they are a fairly decent price. Here is a picture of mine from the weekend. 1st time in daylight for about 11 years, I've taken the tank and saddle off to make it easier to work on. But I think she is basically sound apart from the clutch centre boss and clutch plates I've got to replace. http://i1121.photobu...0%20MX/bike.jpg yeah mines a small bath but not as small as some, I can do a carb body with turning it over occasionally as its not completely submerged. Dont expect miracles they arent industrial ones after all! Mine is big enough to fit a CD into. This one in fact http://ie.farnell.com/duratool/d00351/cleaner-ultrasonic-1-4l/dp/1316381 my bike is more of a rolling restoration than a full on one, it has been rough in the past...I owned her from new and used as a winter hack for many years. yours looks really promising I must say, should come up really nice, If you decide to do her up nice why not show us in the projects forum...it would be good to follow and try to answer any questions you might have. Let me know about the spigot...that carb body is at work. I dont want to pull it out for nothing. Link to comment Share on other sites More sharing options...
roffster Posted November 10, 2011 Author Share Posted November 10, 2011 Anyway, I whipped off the carb and took a picture from each side with some labels to aid the discussions. I looked very hard and scrubbed a bit and can just make out a number on the carb body it is 1R7 00 so it matches with the frame and engine type number. The float arms are different to the diagram in the MX supplement of the manual but the rest of it looks the same, so perhaps the float chamber was kitted out from the spares box on a friday afternoon in Mikuni?? http://i1121.photobucket.com/albums/l503/roffster/Yamaha%20DT%20250%20MX/carbengineside.jpg In the photos I've used the same letters for the parts even if they appear more than once. In this one 'A' is what we think is a breather and the carb diagram in the manual would tend to agree. When you blow through it air comes out of the fuel pipe and somewhere else that I wasn't able to identify but there is obviously an internal airway linking several things. This would seem to back up the breather theory as it does not go straight into the venturi. From the front of the carb you can see 'B' and 'G' are duplicates but 'G' is blanked at the surface and 'B' goes in but does not seem to go straight into the venturi. I couldn't really get at to blow into it but it doesn't seem to allow air through, so maybe this is blanked inside because on other variations of the same basic carb this is where the oil feed is (RD250). The inside and outside of 'B' are the same sort of dirty so it doesn't look like there has been a oil feed pushed in there. 'H' is where the number 1R7 00 is faintly stamped. Next up is the carb from the clutch cover side. http://i1121.photobucket.com/albums/l503/roffster/Yamaha%20DT%20250%20MX/Carbclutchside.jpg 'A' seems to connect in some way to the passage you can see going left to right including the choke mechanism. Inside a small passage starts before the slide and joins the inlet just after the slide (choke?) 'B' you can see the uniform dirt and colouration. In the next picture you can see the start of the channel I mention above which might be the choke circuit (sorry I am not a mechanical whiz, this is my project to learn more. A nice simple two stroke ) http://i1121.photobucket.com/albums/l503/roffster/Yamaha%20DT%20250%20MX/carbairfilterside.jpg When I blew into 'A' I don't think any air came out of 'D' or 'E' Finally the Carb from gear lever side http://i1121.photobucket.com/albums/l503/roffster/Yamaha%20DT%20250%20MX/Carbgearchangeside.jpg 'G' opposite 'B' and as mentioned blanked at the surface unlike 'B' 'F' is the one breather/overflow I can identify positively. There you go folks, does the confirmation of the number on the carb help any. All answers and suggestions are gratefully received. Link to comment Share on other sites More sharing options...
roffster Posted November 10, 2011 Author Share Posted November 10, 2011 Just found a couple of links that show the oil line going onto the spigot on the carb http://media.photobu..._2944Medium.jpg http://www.advrider....ad.php?t=347877 Tony they are the best pictures I've seen so far and it seems to clear as day now. So my photo journalist bit above is useless. Thanks for your help. Much appreciated. Link to comment Share on other sites More sharing options...
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