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Dt125 wont rev above 7000rpm


Lloydi
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Hi there all, i picked up my dt125 yesterday its a 2002 dt125r, it revs cleanley up to 10, 11 thousand revs when its stationary, as soon as you set off in first it wont go past 7000 revs in all gears and almost gives up in 5th and 6th, it feels like its electronically restricted, i just wondered if anyone has experienced this before and if so what the hell is wrong with it, my mate has just bought the exact same bike but a 2003 model and it has the same problem, any help would be greatly appreciated, many thanks Tom :)

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Hi there all, i picked up my dt125 yesterday its a 2002 dt125r, it revs cleanley up to 10, 11 thousand revs when its stationary, as soon as you set off in first it wont go past 7000 revs in all gears and almost gives up in 5th and 6th, it feels like its electronically restricted, i just wondered if anyone has experienced this before and if so what the hell is wrong with it, my mate has just bought the exact same bike but a 2003 model and it has the same problem, any help would be greatly appreciated, many thanks Tom :)

Tom so you are just 17 and a learner with an A1 category licence therefore you should be riding a restricted bike until you pass your test. if you find out the reason for this apparent lack of performance is due to any restriction the manufacturer did you will void your insurance if you remove it. Not what you wanted to hear I know

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Tom so you are just 17 and a learner with an A1 category licence therefore you should be riding a restricted bike until you pass your test. if you find out the reason for this apparent lack of performance is due to any restriction the manufacturer did you will void your insurance if you remove it. Not what you wanted to hear I know

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i know it would slighty void my insurance, :rolleyes: but it seriously struggles to go really and its not much fun in the sun in the middle of summer having every man and his dog overtake you on a ride out

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i know it would slighty void my insurance, :rolleyes: but it seriously struggles to go really and its not much fun in the sun in the middle of summer having every man and his dog overtake you on a ride out

It wont slightly void your insurance , IT WILL void your insurance, what sort of speeds are you getting upto on your DT, max on your liecense is 62.5mph, the maximum BHP allowed on your liecence is 14.6bhp im not sure what the restriction is on your dt but it there for a reason you could change the sprockets but then you would loose the bottom grunt for a few MPH top end , getting your test passed A2 would be the easiest option then your upto 33 bhp

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It wont slightly void your insurance , IT WILL void your insurance, what sort of speeds are you getting upto on your DT, max on your liecense is 62.5mph, the maximum BHP allowed on your liecence is 14.6bhp im not sure what the restriction is on your dt but it there for a reason you could change the sprockets but then you would loose the bottom grunt for a few MPH top end , getting your test passed A2 would be the easiest option then your upto 33 bhp

yeah i know it will void it. but it struggles to do 40 it really doesnt rev right at all. i am going for my theory soon and hopefully taking the test too soon :)

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10 year old 2 stroke wont rev, de coke'd it.

Take the exhaust off and have a look in the pipe and up the exhaust port, chances are its coverd in oily carbon build up.

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Thanks CBD :) i was thinking that too but when i bought the previous owner gave me a reciept for piston and rings and said he fitted them a few days ago, the reciept it dated the 18th of feb so it must have a new one in but never the less may be worth a look inside :) hoping to get it running right for the end of the week ^_^

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Thanks CBD :) i was thinking that too but when i bought the previous owner gave me a reciept for piston and rings and said he fitted them a few days ago, the reciept it dated the 18th of feb so it must have a new one in but never the less may be worth a look inside :) hoping to get it running right for the end of the week ^_^

Ding dong alarm bells ring.

Did he know what he was doing?, why fit a piston but not bore it?, why did it need a piston?

You need to have the top off to check. Then you know the bore/rings are actually OK and that it has proper coolant etc.

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Ding dong alarm bells ring.

Did he know what he was doing?, why fit a piston but not bore it?, why did it need a piston?

You need to have the top off to check. Then you know the bore/rings are actually OK and that it has proper coolant etc.

To answer your first question probably not as the engine was held in by the swinging arm engine mount and the top bracket that connects the frame to the cylinder head. the front engine mount bolt wasnt even there. ive had the head and the barrel off the bore seems okay with no major scoring, the powervalve is all working correctly too, there doesnt seem to be much carbon deposit in the engine all looks pretty clean, ill take it out for another ride tomorrow and try see what is going on with it. thanks for the help :D

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