Dean_DT Posted August 21, 2011 Share Posted August 21, 2011 ok so i was out off road, in very wet conditions, on the DT125R a couple weekends ago when it got a wee bit spluttery. I also noticed at the time that the bike had gotten far more smokey than it had been and smelled heavily of fuel/2T. There was also what looked like frothy oily water coming from the crankcase breather. After a couple of drier rides, the bike was running fine again, although still smelled strongly, and was still smoking strongly. The bike was taken home and left for a couple of days, when i went to start it it fired first kick, and settled to idle nicely, although was still smoky. I ran it up the road and seemed a bit hesitant at anything other than full throttle. Figured i had water in there, so pulled the plug and cranked her over a few times, cleaned plug up, refitted and she was better, but still not quite right. i left it for a few days and when i tried to start it next it started first kick, then died immediately. i managed to get it to fire on next kick and held the revs on, then tried riding it... massive backfires, boggy as hell and generally didnt want to play ball! This time it STANK of fuel and 2T. pulled the plug and it was black and oily. Cleaned plug up, got it started, kept revs on and rode it for 5mins, and it almost wanted to idle, so i wound the idle air screw out a bit and she idled at 2.5k rpm, anything less and it was trying to cut out. Fast forward a few days, and the bike wouldnt even start. wouldnt kick or bump. Did do a singular massive backfire though, which im sure the neighbours appreciated at 10:30pm! I have removed the Carb, and cleaned everything out, there was a fair bit of crap in the float bowl, and also a nice blob of gritty mud in one of the jets ( one with 4 holes in it??) reassembled and still wont start. Also cleaned out all breathers, inlet, air box etc. Now the only things i have changed on the bike are: Throttle cable (top half) was repaired using a universal repair cable. New plug New air filter. Brake pads and Tyres etc - non engine stuff Now i am thinking that as i have too much fuel AND 2T, that the most likely culprit is the throttle cable itself, as this controls the amount of both fuel and 2T being pumped into the engine. I have a new one ordered, but wont be here until tuesday, so does anyone have any other suggestions in the meantime? From what i have found when changing pads etc, it would appear that the previous owners to the bike never did any maintenance, instead just choosing to bodge things up when it broke! Any advice/help welcomed as i dont really have much of a clue when it comes to bike engines! Link to comment Share on other sites More sharing options...
Dean_DT Posted August 21, 2011 Author Share Posted August 21, 2011 FIXED!!!!!!!!!!! Cable was snagging in junction box causing too much 2T and fuel at idel/low revs. Free'd and lubed it up temporarily until i get my new one tuesday, chucked a new plug in, and she's back! Also swapped in a BR8ES plug instead of the BR9ES, and i swear it makes all the difference! bike runs ok with the 9, but is so much more crisp with the 8! Link to comment Share on other sites More sharing options...
AndyDtr08 Posted August 21, 2011 Share Posted August 21, 2011 I'm not sure what difference the 9/8 plugs would make but i would stick with the recommended. Yamaha mechanics know alot more than you do ( no offence intended) so for the sake of a reliable bike, you would be better off keeping eveything standard unless you are sure there could be no bad side effects! Link to comment Share on other sites More sharing options...
AndyDtr08 Posted August 21, 2011 Share Posted August 21, 2011 Oh and glad you managed to fix your bike! I went to view a DTR a few days ago that was being sold and it was state. It angered me to see a DTR that had been treated so badly and was soon to become scrap metal! Link to comment Share on other sites More sharing options...
Dean_DT Posted August 21, 2011 Author Share Posted August 21, 2011 I understand and would agree with your comment mate, however i do not know exactly what state of tune the bike is in, so im just running with what feels right atm until i strip and rebuild her. At present the only mods i know of are a full Big one exhaust system, and "snorkel" removed from airbox. Until i take the reed block out, check jet sizes etc i dont really know what should be what for the best! When i got the bike it was running a Bosch Super 4 car spark plug, and ran nicely with that! with the standard plug she runs alright, but with the later DT125RE plug she runs a LOT better. Revs far more crisply. I Will have an BR9ES in my pocket at all times as a spare though, so will have to see how long this one lasts and what if any ill effects it has. i registered on the DT125 forum as i spotted a local bike that was cheap enough to harvest for parts for mine, but they still havent approved me yet so cant get any more info! Better its used as parts than not at all i suppose! Link to comment Share on other sites More sharing options...
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