c_braddon Posted August 21, 2011 Report Share Posted August 21, 2011 my 2005 txt250 pro was being ridden hard around my field when i noticed a slight power drop, very similar to when its running out of fuel. so i switched it to reserve tank which made no difference. looked over my shoulder and could see lots of white smoke coming from the exhaust. i slowly rode it back to my house when the power got less and less until it stalled and died. any suggestions what caused this, what the problem is, and how i get it running again? thanks Quote Link to comment Share on other sites More sharing options...
dgshannon Posted August 21, 2011 Report Share Posted August 21, 2011 my 2005 txt250 pro was being ridden hard around my field when i noticed a slight power drop, very similar to when its running out of fuel. so i switched it to reserve tank which made no difference. looked over my shoulder and could see lots of white smoke coming from the exhaust. i slowly rode it back to my house when the power got less and less until it stalled and died. any suggestions what caused this, what the problem is, and how i get it running again? thanks As a general rule... Blue Smoke = Oil and White Smoke = Water/Coolant. Whether a seal, water pump, etc. is sounds as if your coolant is leaking into the combustion cycle. A little at first, but then worse until it stalled, and died. Time to play investigator. For my money, I would start at the water pump. Quote Link to comment Share on other sites More sharing options...
c_braddon Posted August 21, 2011 Author Report Share Posted August 21, 2011 Ok so ive been out there tinkering for a few hours now. Given it a good service etc and its running. Its not running right though, and when i open the throttle its like when you first start the bike and before it has warmed up. Like the revs increase a little not as much as they could but its not a smooth rev if you know what i mean. I can only describe it as sounding like when you first start a cold engine. Ive had it idling for 10 mins or more and taken it for a little ride around the driveway and it still doesnt seem to 'warm up' as such. Any suggestions? Thanks. Quote Link to comment Share on other sites More sharing options...
02-apr Posted August 21, 2011 Report Share Posted August 21, 2011 From my experience you have somehow got diesel in the tank. Quote Link to comment Share on other sites More sharing options...
c_braddon Posted August 21, 2011 Author Report Share Posted August 21, 2011 From my experience you have somehow got diesel in the tank. nope impossible. the only diesel i ever use is in my car and it stays there!!! Quote Link to comment Share on other sites More sharing options...
lowbrow Posted August 21, 2011 Report Share Posted August 21, 2011 You need to listen to Mr Shannon. White smoke is caused by the motor trying to burn coolant with the petrol/air mixture. The most likely cause of this is that the rubber 'O' rings between the cylinder barrel and cylinder head have failed and need to be replaced. This will make the motor run hot and could result in a piston siezure if you keep using it like it is. Quote Link to comment Share on other sites More sharing options...
rockyrider Posted August 21, 2011 Report Share Posted August 21, 2011 my 2005 txt250 pro was being ridden hard around my field when i noticed a slight power drop, very similar to when its running out of fuel. so i switched it to reserve tank which made no difference. looked over my shoulder and could see lots of white smoke coming from the exhaust. i slowly rode it back to my house when the power got less and less until it stalled and died. any suggestions what caused this, what the problem is, and how i get it running again? thanks Hi Mate, This too sounds like a classic symptom of a blown head gasket. the reason why it died eventually is because the coolant overwhelms the fuel mixture, and wins out. You would be well advised to look for a coolant leak into the cylinder. Quote Link to comment Share on other sites More sharing options...
stockers Posted August 21, 2011 Report Share Posted August 21, 2011 my gas gas did this today actually but i dont think its sized, how do you put more coolant into the bike because i couldnt find a place? i have a 1993 gas gas. Quote Link to comment Share on other sites More sharing options...
c_braddon Posted August 22, 2011 Author Report Share Posted August 22, 2011 You need to listen to Mr Shannon. White smoke is caused by the motor trying to burn coolant with the petrol/air mixture. The most likely cause of this is that the rubber 'O' rings between the cylinder barrel and cylinder head have failed and need to be replaced. This will make the motor run hot and could result in a piston siezure if you keep using it like it is. Ok, thanks...sounds expensive!! :-( I wont be using it any more as its not rideable really as power output is about 20%. Im fairly competant at maintaning my bike etc so is this something i could do myself or would i be best taking it to a garage? I changed the engine oil and when looking through the spy glass when it runs the oil appears white, which could possibly back up your theory. Would you mind describing in a bit more detail what requires doing and where you think they are located. Im thinking i may just take it to the garage and cough up the Quote Link to comment Share on other sites More sharing options...
lowbrow Posted August 22, 2011 Report Share Posted August 22, 2011 If the oil is white and milky its been contaminated by water and the most likely souce is the water pump seal which should be changed. The crankshaft main bearings are fed with oil from the gearbox and if the crank seals are 'shot' the motor could be sucking in oil and water. Badly worn crank seals will also reduce power. Changing crank seals is probably beyond your capabilities but changing the 'O' rings between head and barrel is straight forward. Drain the coolant and undo the allen bolts securing the cylinder head. Lift off the head, retrieve the old 'o' rings and clean the faces of the head and barrel. Apply a smear of grease to the grooves in the head to help hold the new 'o' rings in place and refit the head using new copper washers (if fitted) under the allen bolts. A search of this forum will confirm the correct torque setting which I think is about 14 foot pounds. Take a look inside the barrel while the head is off for scoring, seizure or wear. Alternatively, and before you spend any money take the bike to someone like Robin Martin who should be able to diagnose the problem by listening to the motor and give definitive advice. Quote Link to comment Share on other sites More sharing options...
c_braddon Posted August 23, 2011 Author Report Share Posted August 23, 2011 If the oil is white and milky its been contaminated by water and the most likely souce is the water pump seal which should be changed. The crankshaft main bearings are fed with oil from the gearbox and if the crank seals are 'shot' the motor could be sucking in oil and water. Badly worn crank seals will also reduce power. Changing crank seals is probably beyond your capabilities but changing the 'O' rings between head and barrel is straight forward. Drain the coolant and undo the allen bolts securing the cylinder head. Lift off the head, retrieve the old 'o' rings and clean the faces of the head and barrel. Apply a smear of grease to the grooves in the head to help hold the new 'o' rings in place and refit the head using new copper washers (if fitted) under the allen bolts. A search of this forum will confirm the correct torque setting which I think is about 14 foot pounds. Take a look inside the barrel while the head is off for scoring, seizure or wear. Alternatively, and before you spend any money take the bike to someone like Robin Martin who should be able to diagnose the problem by listening to the motor and give definitive advice. yeah thanks i think i will take it down to him sometime or give him a call. sounds a bit too confusing to me and i will probably screw it up even more! thanks for your thoughts. Quote Link to comment Share on other sites More sharing options...
c_braddon Posted September 3, 2011 Author Report Share Posted September 3, 2011 turns out the exhaust had a blockage whih caused some sort of pressure build up and blew something in the engine and melted part of the exhaust inner. cost a few quid to put right! Quote Link to comment Share on other sites More sharing options...
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