rift. Posted February 19, 2005 Share Posted February 19, 2005 Hi, Im new here.. And i'll begin. I recently bought a 1990 dt125r although i dont know if the engine or carb is from a 1990. Ok Its had a new piston, re-bored barrel, New head gasket Its got spark Its got compression Its got fuel in carb Its got oil in pump I have tried to push it down the road to bump it but i makes a wierd niose coming from carb (i think). Everytime i kick it, after i take out plug and it has oil on the plug about half way up the thread I have asked many people what it could be and they have answer well but none have solved my problems. Could this forum be the one that helps me to run it..... Please do... Thanks -Rift. Link to comment Share on other sites More sharing options...
Moderator Beezkneez Posted February 19, 2005 Moderator Share Posted February 19, 2005 welcome onboard m8, i'm sure one of the 2 stroke guru's will be along to help you out Link to comment Share on other sites More sharing options...
Moderator YamaHead Posted February 19, 2005 Moderator Share Posted February 19, 2005 to the Forum Rift Sounds like your oil pump might need an adjustment?.....a bit too rich. Link to comment Share on other sites More sharing options...
skyline Posted February 19, 2005 Share Posted February 19, 2005 oil half way up the thread?! im sure oil isnt even meant to get on the thread, are you sure you have enough compression, has it been checked using the proper tools? i think its meant to be around 18psi for a dt125 although im not sure, i do know though a friend of mine ran one on only 8psi compression....although it would only bump up and ran like a bag of shite, but we never thought there wasnt enough compression on that. anyway going off track there. all in all oil going up the thread isnt good, get that bit checked out certainly. Link to comment Share on other sites More sharing options...
jimjam Posted February 19, 2005 Share Posted February 19, 2005 It does not sound too serious. If it comminf fom the carb then this is where you should start. Hopefully there is a model mark on your carb and you check with Twisted. I think you need to check your carb and start with the basics. Nice and clean and that your choke works and also that your gap at the plugs is right. Link to comment Share on other sites More sharing options...
rift. Posted February 20, 2005 Author Share Posted February 20, 2005 The carb model number is 3MB00 I have cleaned inside carb and cleared jets. Im a bit worried about the oil getting up onto plug Yea forgot to check the gap..but will do.. Link to comment Share on other sites More sharing options...
mickt26 Posted February 20, 2005 Share Posted February 20, 2005 This might be stating the obvious, but are you using a fresh plug each time you check if it's fouled or not? Try checking the float height too- if it's set wrong then that could lead to the plug fouling problem. Also, on a 15 year old bike the reeds may be a bit tired- have you checked them? Even if they aren't chipped or damaged they may well be too worn to seal properly. What exactly was done to the engine and who by? Was it running when you bought it? The oil on the plug threads may just be from unscrewing the plug and bringing oil up on the plug end into the threads- refitting into the head will leave a trace of oil on the threads and subsequent removal will also show oil. If all else fails, try removing the oil feed from the carb rubber and running the feed into a plastic bottle or something zip-tied to the bike. Blank off the oil feed on the carb rubber using a small length of oil line with a bolt or something pushed into the open end and try running the bike on a little premix (fresh fuel at 32:1 with a good oil) to see if it is the pump which is set wrong. It's not hard to do and doesn't have to be a permanent change, you're only checking if the pump's set right. Mick. Link to comment Share on other sites More sharing options...
Twisted2004 Posted February 21, 2005 Share Posted February 21, 2005 Welcome aboard! Have you set the carb up properly?? Ie float height, pilot screw, idle screw? What sort of noise is coming from the carb?? Is the fuel gettin to the carb and is it clean? Ie no bits floating around. is the air filter alright? Did you get a new plug? As for the oil pump, sorry cant be much help, i havent had a problem with it yet so i havent had to look at it! Link to comment Share on other sites More sharing options...
rift. Posted February 21, 2005 Author Share Posted February 21, 2005 My friend checked over the reads and carb so they are alright. Its a brand new plug... The pilot screw and idle screw are the same thing!! (to my knowledge) Its the throttle stop screw that is also untouched and thus unadjusted. im not sure how to check float height (is it when you get a tube and hook it up the little pipe off the bottom of carb, then open the drain screw?? and watch the fuel come up to the top of the floats?) The noise from carb sounds empty...not exactly sure. So Mickt26 are you saying that theres a pipe coming from oil pump to carb? (feed) Its not like that on my bike... Thanks for your suggestions Link to comment Share on other sites More sharing options...
mickt26 Posted February 21, 2005 Share Posted February 21, 2005 My friend checked over the reads and carb so they are alright. Its a brand new plug... The pilot screw and idle screw are the same thing!! (to my knowledge) Its the throttle stop screw that is also untouched and thus unadjusted. im not sure how to check float height (is it when you get a tube and hook it up the little pipe off the bottom of carb, then open the drain screw?? and watch the fuel come up to the top of the floats?) The noise from carb sounds empty...not exactly sure. So Mickt26 It's just Mick... are you saying that theres a pipe coming from oil pump to carb? (feed) Its not like that on my bike... Thanks for your suggestions Did your mate check that the reeds were seating and sealing properly against the cage? If the reeds are tired then they may not be sealing properly. And a brand new plug that's fouled is still a fouled plug. Buy some more (plugs). There should be an oil line coming from the oil pump going to the carb mounting rubber (where the carb attaches to the reed cage, IIRC). If there isn't then it's possible the bike was being run on premix anyway. Is it a road bike, or a play bike? And you still haven't told us if it was running when you bought it. Mick. Link to comment Share on other sites More sharing options...
rift. Posted February 24, 2005 Author Share Posted February 24, 2005 sorry Mick... Anyways, yeah i bought the bike non-runner style.. I had to put the piston in, the head on + new gasket,and put everything else on... There is a pipe coming off oil pump and it goes onto carb/reeds joint. Its going to be a play road bike .. I think its compression, i still haven't tested it because of not haveing the right tools. Thanks Link to comment Share on other sites More sharing options...
mickt26 Posted February 25, 2005 Share Posted February 25, 2005 sorry Mick... No worries. No need to type more than you have to, eh? Anyways, yeah i bought the bike non-runner style.. I had to put the piston in, the head on + new gasket,and put everything else on... There is a pipe coming off oil pump and it goes onto carb/reeds joint. Its going to be a play road bike .. I think its compression, i still haven't tested it because of not haveing the right tools. Thanks Right. So you've got a new piston, rings and everything's the right size for the bore? Has it been rebored or was the bore ok? if it's a nice fresh top end then compression shouldn't be a factor. The weird sound you mentioned- is it kind of a gurgling noise? It's possibly fuel being pushed out the exhaust port after it's failed to start. Turn the fuel off, remove the spark plug and kick it over a few times (remember to ground the plug or you can damage the CDI) This should get rid of any excess fuel. Refit a fresh plug, ignition on, kill switch on, choke on, and kick it over. Mick Link to comment Share on other sites More sharing options...
rift. Posted February 25, 2005 Author Share Posted February 25, 2005 It was rebored About the fuel going through exhaust port...sounds similar to what happened to me. When i first got the bike i had to test the seals, i did this with oil in the crank-case. I then kicked it a few times a realised that the oil had all gone into my exhaust. After empting the exhaust there ws no oil in crank-case and seals are ok. The sound isnt so much a gurgling noise, its a turn over but no sign of firing. I did what you said and still nothing. I did however notice that there was now fuel on the plug, i have burnt that off already.(Gas hob) I am going to take off the exhaust to check if anything has come out of port. Link to comment Share on other sites More sharing options...
mickt26 Posted February 25, 2005 Share Posted February 25, 2005 Whereabouts are you? Anywhere near NE England? And- sorry to keep banging on about it- did you use a new plug? When you checked for a spark was it nice and big, or feeble and crappy? Mick. Link to comment Share on other sites More sharing options...
rift. Posted February 26, 2005 Author Share Posted February 26, 2005 The spark plug is alright. It had a bit of fuel on it when i took it out but i burnt the excess off. No... Sorry I live Near London. I have no idea what it could be..... Link to comment Share on other sites More sharing options...
mickt26 Posted February 27, 2005 Share Posted February 27, 2005 Try checking the resistance of the pulser coil- it should be around 280-420 ohms. If it's nowhere near that could be the answer and you'll need a new one. Do you have any mates you could borrow one off to check? And buy a fresh plug. You might think you've cleaned the other one but there could still be some crud on there causing the spark to short across the terminals, rather than ignite the fuel. Mick. Link to comment Share on other sites More sharing options...
rift. Posted February 27, 2005 Author Share Posted February 27, 2005 Try checking the resistance of the pulser coil Pulse coil??? CDI? or the thing the spark gets its aprk from.. Thanks Link to comment Share on other sites More sharing options...
mickt26 Posted February 27, 2005 Share Posted February 27, 2005 It's the thing sitting next to the flywheel/magneto that sends the message to the cdi to fire. Looks like a little coil with 2 wires coming out of it. While you're poking around in there, you may also want to check on the condition of the flywheel/magneto and the source coil (where the CDI is charged from) and lighting/charging coils (which power the bike's system). Check for rust/corrosion and moisture. It may be worth giving everything a good blast of WD40. If they're suspect then you'd get a spark outside the cylinder but there wouldn't be enough current to fire the plug in a high compression, oily, wet atmosphere (the cylinder). Mick. Link to comment Share on other sites More sharing options...
rift. Posted March 1, 2005 Author Share Posted March 1, 2005 OK I've checked the pulser coil and its fine its 320ohms. I checked the HT coil and only the primary winding had resitance. I change around my CDI and there was no improvement. (i have 2) I think the CDI's are fine but im not sure whats happening about the source coil. I will now check the Flywheel generator and get back to you. I just found out that there is oil coming from the left-hand side valve cap. Cheers Link to comment Share on other sites More sharing options...
Admin Alex Posted March 1, 2005 Admin Share Posted March 1, 2005 Its always the last thing you check Link to comment Share on other sites More sharing options...
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