mcferreira100 Posted June 20, 2013 Posted June 20, 2013 Fitted carb and tank..put in some premix and had a go at starting it. After quite a few kicks went for some quickstart. Couple kicks later it started. Not running too bad but not wanting to idle so fiddled with idle screw. But after she idles herself warm and I switch off it battles to start again. Some carb adjustment maybe?
Moderator Airhead Posted June 20, 2013 Moderator Posted June 20, 2013 Get it warmed up and then apply the choke, this should kill it dead and is an easy way to prove the choke cct is working. The problem you are having possibly indicate that it isnt
mcferreira100 Posted June 20, 2013 Author Posted June 20, 2013 Hi Airhead..Will try..just to get it started again..I have the feeling something may be blocked. Will try again with some quickstart tomorrow.
nayruf Posted June 20, 2013 Posted June 20, 2013 Hi Personally I don’t like quick start as it also degreases the cylinder bore/piston and crank, I would rather just put a few drops of petrol in the plug hole and rely on the vapour from this fuel to enhance the ignition,
Moderator Airhead Posted June 20, 2013 Moderator Posted June 20, 2013 Heres how the choke cct works If your bike has been standing unused for a while, theres a good chance the small hole 'A' is blocked or there is a build up of crud in the lift tube 'B'
mcferreira100 Posted June 22, 2013 Author Posted June 22, 2013 Ok..carb off, stripped, sprayed carb cleaner everywhere..blew out with compressed air..cleaned out by the choke. Could see light thru both jets. Assembled again, yet it still only runs for couple of seconds if I put fuel in by the spark plug. Soon as I try give some throttle it dies. Any more suggestions?..maybe take carb in to the professionals for a makeover. Let me just say there is no air cleaner element fitted..as well as no hoses from the carb (drain lines..oil line..etc). The carb pretty much naked at the moment..would think shouldn`t make a difference as I`m just trying to get it to run.
Moderator Airhead Posted June 22, 2013 Moderator Posted June 22, 2013 you will be losing some vacuum without the filter element fitted so fit one (lightly oiled) and try it again, also if there is no pipe from oil pump to carb then at least you should fit a small length of pipe to the carb spigot and seal this pipe with a screw, or bend it over and tape it off so the spigot is airtight...I take it you're premixing right now
mcferreira100 Posted June 22, 2013 Author Posted June 22, 2013 Hi Airhead..yep premix..once running will check autolube pump. Battling with pics on this site..I know you`re on the YamahaDTClub forum as well ..have put some pics there..also a comment there from Blackhat: Oil pump to carb spigot was sealed. Aha " put your hand over the back of carb, when running. just leave a small gap between fingers, then open throttle,, Yo see piccy 1, that deep hole , did you clean that, thers a small opening at bottom. this feeds choke jet with fuel.. Read more: http://yamahadtclub.proboards.com/thread/1196/started-today#ixzz2WyhxVvCP
Moderator Airhead Posted June 22, 2013 Moderator Posted June 22, 2013 yes I've seen blackhats post...
blackhat250 Posted June 22, 2013 Posted June 22, 2013 Hee " can"t hide anywhere nowadays,,, .. hand over back of carb was to increase vacume,,
mcferreira100 Posted June 23, 2013 Author Posted June 23, 2013 Airhead..in your first pic..where is the long brass tube sticking up on yours at the bottom of the bowl?..you see mine has it. Can I take it off to clean? I presume this is the deep hole Blackhat is referring to for feeding choke jet.
mcferreira100 Posted June 23, 2013 Author Posted June 23, 2013 Also on trying to start..throttle open/closed? 1/4 throttle?
Moderator Airhead Posted June 23, 2013 Moderator Posted June 23, 2013 in my pic the brass tube is 'D' and goes down into the hole 'B', there will be no need to try taking it out and risk damaging it. any blockage will normally be the small hole 'A' The gasket around the top of 'B' needs to be unbroken or the choke wont work. Start with a closed or ever so slightly cracked open throttle, no more than 1/8
mcferreira100 Posted June 23, 2013 Author Posted June 23, 2013 and airscrew all the way in then 1 and 1/4 turns out for factory setting?
Moderator Airhead Posted June 23, 2013 Moderator Posted June 23, 2013 and airscrew all the way in then 1 and 1/4 turns out for factory setting? well yes, but thats when you have an air filter fitted, until then I would just have it 1/4 out
mcferreira100 Posted June 23, 2013 Author Posted June 23, 2013 Another thing is the reed valve. Previous owner said he had to bend it for some reason. Should I not remove it for inspection?
Moderator Airhead Posted June 23, 2013 Moderator Posted June 23, 2013 yes, this could be just another part of the problem, you cant just go around bending them, they will probably need replacing. To test..I.offer it up to my mouth... have to get my lips just right for this procedure... you should be able to blow air through the assembly...but not suck air through Thats what I do anyway but not that i'm suggesting you should do the same, unless you cant think of a better way
mcferreira100 Posted June 26, 2013 Author Posted June 26, 2013 After reading another thread of similar starting problems which got very involved investigating electrics and compression..it was solved by cleaning the carb choke mechanism and airscrew thoroughly. These seemingly huge problems always seem to boil down to simple things. Does anyone have any pics or guidelines of how these items come apart once removed. I would like to concentrate on them. I have noticed a lot of play on the shaft of the choke..making me wonder if its too worn and should be replaced. I removed them today and gave them a through clean again..also soaking the bowl of the carb in boiling water. Carb is assembled and back on the bike again.
Moderator Airhead Posted June 26, 2013 Moderator Posted June 26, 2013 They both simply unscrew from the carb body mcf...how about the reeds then?
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