rite i8 have recenlty bought a dt125 which when ridden slowly is fine. howeva when you rech 50 + it will really start to strugle to pull any more. i have served the bike new filter etc. but am runnin short on ideas now.

could it be low on compresion and if so does any1 know what it should be when tested ?

anyideas welcome see ya round

brian

yer prob time for rebore/piston change or just rings compression ratio should be in your haynes manual mate

good luck

I have a 2001 DTR and it does the same as yours mate, it gets up to 50 fine then struggles to reach 60 if I am going up hill it will only do 50. I don't think its the engine because it has only done around 4000 miles plus ive changed the air filter, removed the speedo re-strictor, changed the transmission oil and bought an after market exhaust and its still the same.

Did you solve the problem?

That sounds like it has some form of restrictor on it.

That sounds like it has some form of restrictor on it.

Yeah it does 63mph tops and there is a guy on the DT forums that has a 98 and he says his does exactly 63mph as well so it must be a re-stricitor. Trouble is the only thing I can think of is the CDI unit and the older ones are near impossible to find these days.

Yeah it does 63mph tops and there is a guy on the DT forums that has a 98 and he says his does exactly 63mph as well so it must be a re-stricitor. Trouble is the only thing I can think of is the CDI unit and the older ones are near impossible to find these days.

mine does 75 standard part from a DEP pipe 13,000miles on clock u sure its not low on compression?

mine does 75 standard part from a DEP pipe 13,000miles on clock u sure its not low on compression?

my 03 dt125r 16000 miles only does 65mph, all standard, where can you get that dep pipe? had a dyno check running a bit rich otherwise ok.

i had that problem with my 2001 DTR, the battery was fkd so i bought a new one and its running fine again now

my 03 dt125r 16000 miles only does 65mph, all standard, where can you get that dep pipe? had a dyno check running a bit rich otherwise ok.

adrenalin pedstop seach it on google...or ask your local bike shop to order u one in cost 130 for the expansion chamber and 70 for the end can goes well souinds real good for a 2 t

People never come back to tell if the suggestions worked well

Shame you lot don't live near me. I'd take great pelasure in pulling one of the bikes apart to find the problem and report back.

i have a tdr 125 which has the same engine as the dt. mine only does 75mph at redline. u can get a cdi from europe for dt/tdr derestricted. its definately the cdi that is restricted co i have got a aftermarket exhaust and a 17tooth front sprog. theres not much point spending to much on it cause ure guna want to see it in a while if u do your test.

rite i8 have recenlty bought a dt125 which when ridden slowly is fine. howeva when you rech 50 + it will really start to strugle to pull any more. i have served the bike new filter etc. but am runnin short on ideas now.

could it be low on compresion and if so does any1 know what it should be when tested ?

anyideas welcome see ya round

brian

I also have a dt125, mine hasnt got a reed restricter, maybe yours has.

hopefully this helped

What i dont understand is that everyone always says that the older dt's are faster than the newer type like mine yet iv never had any problems (12500 miles) have a dep pipe deristricted can reach 85mph on flat land

Baffles me .

Normally I wouldn't believe claims of people doing anything more than 75mph on a DTR. I will accept claims of around 80-85mph now as I have followed a crazy friend of mine and seen with my own eyes 85mph on my YZF clocks. That's a real speed of about 75-80mph which is very respectable for a 125cc scrambler.

Sounds to me like you guys have carb problems. My 2001 DTR with my weight aboard topped out around 65-70mph but accelerated to that speed fairly swiftly.

Gents:

Would probably help if you also shared the information on the number of teeth on your front and rear sprockets - I've a notion that this'll be the crux of your problems.

On an engine this size, they can make a helluva difference - and you'll generally either gear it for good acceleration or higher top end...

(I've no idea what teeth ratios should be used to give the higher top ends, you'll need to pass that info between yourselves).

Paul

Gents:

Would probably help if you also shared the information on the number of teeth on your front and rear sprockets - I've a notion that this'll be the crux of your problems.

On an engine this size, they can make a helluva difference - and you'll generally either gear it for good acceleration or higher top end...

(I've no idea what teeth ratios should be used to give the higher top ends, you'll need to pass that info between yourselves).

Paul

Good thought.

Stock gearing is 16/57 on post 2000 models. I personally opted for a larger front sprocket to stop it revving so hard in top gear. I tried an 18 in the absence of a 17. That was far too big and top speed was very limited. The 17 tooth gave a reasonable balance but due to my weight, sometimes it struggled a bit going uphill or against a strong wind.

Im on stock gearing.

rite i8 have recenlty bought a dt125 which when ridden slowly is fine. howeva when you rech 50 + it will really start to strugle to pull any more. i have served the bike new filter etc. but am runnin short on ideas now.

could it be low on compresion and if so does any1 know what it should be when tested ?

anyideas welcome see ya round

brian

well to get the speed up on my dt i had to play about with the yvps (powervalve) setting about half open to keep a decent top speed. i could get about 80 from her but that was also with knobblies too. hope this is of some use dude

im on knobblies too but im never touching the powervalve.