dave26 Posted May 3, 2008 Share Posted May 3, 2008 hi guys im new to this forum and need sum advice.. i recently bought a dtr 125 ( not sure of the model ) which has been made into complete off road and fully deristricted, it seemed ok when i bought it and after riding it hard it started to lose power in mid revs, then after getting home it wouldnt run at all, i changed the spark plug and hey presto it started again, so today i decided to ride it again and it went ok but with not much mid range power but iff you can manage to get past mid revs it is like a rocket, until it gave in and wouldnt start again and lots of tapping when kicking it over. well not kicking it over literally but i feel like lol so here i am thinking its the piston and rings, oh i also noticed the bikes radiator is not getting hot and that the cable is not connected to the pump, also there is no place to put the 2 stroke oil so i mixed it in a petrol can and poured it in, after that the bike was puffing grey smoke everywere so i assume i put a lil to much oil in the fecker. i got this bike really cheap off a good friend as sumthink to work on but now its stopped running its set me back a little. iff ne of you guys could put me in the right direction on sorting the power issue and help get it running sweet again it would be much appreciated. sorry for the long post guys , just trying to give you a good insight of the bike dave Link to comment Share on other sites More sharing options...
mckenzie Posted May 6, 2008 Share Posted May 6, 2008 it could be a poervalve problem, you should srip the powervalve and give it a good clean, they should be cleaned every 2000 miles or so, carbon builds up and can make them difficult to turn. Also it may be an ignition problem if its eating plugs so you should check that out, also check the carb, there may be dirt in the float bowl chamber that could result in fuel starvation, find out when it was deristricted and if the main jet was changed Link to comment Share on other sites More sharing options...
davva Posted May 7, 2008 Share Posted May 7, 2008 it could be a poervalve problem, you should srip the powervalve and give it a good clean, they should be cleaned every 2000 miles or so, carbon builds up and can make them difficult to turn. Also it may be an ignition problem if its eating plugs so you should check that out, also check the carb, there may be dirt in the float bowl chamber that could result in fuel starvation, find out when it was deristricted and if the main jet was changed thanx mckenzie, b4 i start to strip the powervalve i took off the front exhaust and had a quick look at the piston and found i could wobble it a little so im still thinking rings and piston or maybe both, im gonna take out the powervalve tomorrow and give it a good clean just incase, also the new spark plug i put is is sparking well so i will eliminate that for the time being and get on with the powervalve, iff it turns out to be the piston/rings were could i find 1 as no shops around my area does them and im not sure of the year so i cant order 1 either, would i also need a rebore??? Link to comment Share on other sites More sharing options...
mckenzie Posted May 7, 2008 Share Posted May 7, 2008 thanx mckenzie, b4 i start to strip the powervalve i took off the front exhaust and had a quick look at the piston and found i could wobble it a little so im still thinking rings and piston or maybe both, im gonna take out the powervalve tomorrow and give it a good clean just incase, also the new spark plug i put is is sparking well so i will eliminate that for the time being and get on with the powervalve, iff it turns out to be the piston/rings were could i find 1 as no shops around my area does them and im not sure of the year so i cant order 1 either, would i also need a rebore??? did u feel the piston throught the exhaust port?? if its wobbling then yes you could be looking at a top end rebuild and more than likely a rebore, my top end went around 12000 miles and that was me riding it like i stole it nearly every day which was enevatable but none the less inpressive for that milage, compared to an rs or tzr etc! when mine went i could rev it up a little bit then it died and spat bits of rings out the exhaust with a few puffs and bangs, the barrel was suprisingly tidy but i went to .25 oversize (1st oversize) just to be safe, i also had the crank rebuilt and new main bearings while i was at it. you will need to strip the top end of her and get a proper look at it, find someone that does rebores (usually £20) top end kits and crank kits are cheap and can be found on ebay or wemoto or if you have the cash just send it to Stan Stevens http://www.stanstephens.com/street.htm http://www.pjme.co.uk/acatalog/Online_Part..._DT125R_19.html Im sending my barrel and head to him for a stage 3 tune this summer, Im hoping she'l crack the ton, already getting 80-85 with 2 teeth up on the front sproket and its standard power!! so it shouldnt have any trouble!! anyway stick at it and get her running again!! Link to comment Share on other sites More sharing options...
davva Posted May 8, 2008 Share Posted May 8, 2008 did u feel the piston throught the exhaust port?? if its wobbling then yes you could be looking at a top end rebuild and more than likely a rebore, my top end went around 12000 miles and that was me riding it like i stole it nearly every day which was enevatable but none the less inpressive for that milage, compared to an rs or tzr etc! when mine went i could rev it up a little bit then it died and spat bits of rings out the exhaust with a few puffs and bangs, the barrel was suprisingly tidy but i went to .25 oversize (1st oversize) just to be safe, i also had the crank rebuilt and new main bearings while i was at it. you will need to strip the top end of her and get a proper look at it, find someone that does rebores (usually £20) top end kits and crank kits are cheap and can be found on ebay or wemoto or if you have the cash just send it to Stan Stevens http://www.stanstephens.com/street.htm http://www.pjme.co.uk/acatalog/Online_Part..._DT125R_19.html Im sending my barrel and head to him for a stage 3 tune this summer, Im hoping she'l crack the ton, already getting 80-85 with 2 teeth up on the front sproket and its standard power!! so it shouldnt have any trouble!! anyway stick at it and get her running again!! hi m8 yeah i checked the piston through the exhaust port, out of all the tools i have my spanner for taking the head off was missing so i couldnt take a better look at that time, im gonna go and take the head off a bit l8er and see the damage,your bike must of been pretty bad for the rings to be spat out the exhaust lol i think my rings are still there but without a closer look i cant be sure, 1 thing i have never done b4 tho is the powervalve i take it the valves are inside the round cover at the side of the head and iff i do take them out how will i know they are in the correct possition when i put it together again? i know my way around a bike but ive never touched the powervalves b4.. ive checked out thje links thanx alot m8 they really helped, im thinking of buying a piston and gasket set from pjme iff the barrel seems ok, ill take a look and let you know. thanx again mckenzie Link to comment Share on other sites More sharing options...
davva Posted May 8, 2008 Share Posted May 8, 2008 hi m8 yeah i checked the piston through the exhaust port, out of all the tools i have my spanner for taking the head off was missing so i couldnt take a better look at that time, im gonna go and take the head off a bit l8er and see the damage,your bike must of been pretty bad for the rings to be spat out the exhaust lol i think my rings are still there but without a closer look i cant be sure, 1 thing i have never done b4 tho is the powervalve i take it the valves are inside the round cover at the side of the head and iff i do take them out how will i know they are in the correct possition when i put it together again? i know my way around a bike but ive never touched the powervalves b4.. ive checked out thje links thanx alot m8 they really helped, im thinking of buying a piston and gasket set from pjme iff the barrel seems ok, ill take a look and let you know. thanx again mckenzie well finay i managed to get the head off and to no suprise 1 of my rings have snapped and the top of my piston has more chips and gauges than a chip chip shop itself, so im gonna order a piston set asap from pjme and see how it goes, the barrel seemd fine until i noticed chips out of that too , these chips are not on the side of the barrel but at the top ( as iff the top of the piston has been hitting it ) so after i put it back together knowing it wont run i kicked it over and all the tapping noises have gone so im hoping just a piston and rings will make it run, i dont wanna buy a new head cos i heared these cost hundreds. 1 more thing is there neway i can drain the water out of the engine so i can flush it cos i got a feeling some of the rings may be in there and only cause me more probs. thanx Link to comment Share on other sites More sharing options...
mckenzie Posted May 8, 2008 Share Posted May 8, 2008 well finay i managed to get the head off and to no suprise 1 of my rings have snapped and the top of my piston has more chips and gauges than a chip chip shop itself, so im gonna order a piston set asap from pjme and see how it goes, the barrel seemd fine until i noticed chips out of that too , these chips are not on the side of the barrel but at the top ( as iff the top of the piston has been hitting it ) so after i put it back together knowing it wont run i kicked it over and all the tapping noises have gone so im hoping just a piston and rings will make it run, i dont wanna buy a new head cos i heared these cost hundreds. 1 more thing is there neway i can drain the water out of the engine so i can flush it cos i got a feeling some of the rings may be in there and only cause me more probs. thanx you will have to split the cases and clean everything, people are breaking dt's all the time on ebay, you will get a dt/tzr barrel and head for under £100 if you are lucky! Link to comment Share on other sites More sharing options...
davva Posted May 8, 2008 Share Posted May 8, 2008 you will have to split the cases and clean everything, people are breaking dt's all the time on ebay, you will get a dt/tzr barrel and head for under £100 if you are lucky! hi m8 found a local shop that is gonna do me a rebore and piston kit for £60 all in so hopefully it should be back up and running sumtime tomorrow as for splitting the cases to get rid of the water ill do that tomorrow also and let you know iff she runs again or not, thanx for the advice bud Link to comment Share on other sites More sharing options...
davva Posted May 9, 2008 Share Posted May 9, 2008 hi m8 found a local shop that is gonna do me a rebore and piston kit for £60 all in so hopefully it should be back up and running sumtime tomorrow as for splitting the cases to get rid of the water ill do that tomorrow also and let you know iff she runs again or not, thanx for the advice bud oh well all went well and she's running again, they guy who did the rebore told me this is the last bore it could have and he doesnt know how long it will last wtf man lol, neway just need to run the fecker in now b4 i can really enjoy sliding around in the mud, in the mean time tho i will look about for a decent barrel and head or i have another dtr to pick up tomorrow and iff that doesnt run i will ust it for parts. Link to comment Share on other sites More sharing options...
racerd Posted September 18, 2008 Share Posted September 18, 2008 what size piston kit did you put in you can go up to 2.00mm and 2.50mm over size then the power valve needs altering so the piston and rings dont hit the power valve Link to comment Share on other sites More sharing options...
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