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DT 125 R running poorly!


sheffy
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Not to sound offensive, but you don't recommend re jetting for a performance exhaust, where as almost everyone i've spoken to (online and in garages....even the shop who sold it me) says it may need rejetting.

Not a dig by the way!

Cheers for the help!

??? where exactly did I say that you shouldnt re-jet

I think you'll find I said re-jet 1 size but dont expect it to give you back 10mph

as for 'performace exhaust'...well it sounds good but 'after market' exhaust would be more accurate, the original exhaust isnt called a 'performane' one is it and it does quite a good job eh at 80mph :)

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Sorry airhead, I just had an idea though... we're all talking about making it richer when.......... isn't bogging down a 'rich symptom' so leaning it out may make more sense, seeing as it refuses to accelerate in 6th and slows right down?

Any ideas?

Cheers.

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Sorry airhead, I just had an idea though... we're all talking about making it richer when.......... isn't bogging down a 'rich symptom' so leaning it out may make more sense, seeing as it refuses to accelerate in 6th and slows right down?

Any ideas?

Cheers.

This term 'bogging down' lots of people use that expression these days to describe an overly rich scenario...when the mixture is over rich or 'bogging down' back in the day we used to describe this as 'Four Stroking' ie...it feels like it is firing every other beat of the engine not every beat as it should. You need to give it wide open throttle or 'WOT' to determine this, get it right at WOT and then at part throttle 1/2 - 3/4 do the same thing by adjusting the carb needle posn, up to richen and down to lean...always go leaner in the jet and needle posn with a big serving of CAUTION, only do it if you experience 'bogging down'. plug colouring should also be part of the testing as you are no doubt aware

Another thing...i think some of the earlier bikes didnt have a 240 jet but had a 210? so it would be a bit silly not to know whats in there and go buying jets ;)

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Get the plug out and check its colour man..

Lots of ifs and buts in here, fire her up let it warm up give it full revs and flick the kill switch at full revs (plug chop) the plug will tell all!!!

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Get the plug out and check its colour man..

Lots of ifs and buts in here, fire her up let it warm up give it full revs and flick the kill switch at full revs (plug chop) the plug will tell all!!!

has to be WOT ken, full revs can be got to at part hrottle openings too....sheffy of course you dont have to be doing this at stupid speeds, 3rd or 4th gear is fine and a long uphill road to give some load

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even with out all this full open throttle etc etc just taking the plug out after an average use would surfice - i change my plug every 3 months and the colour is always light brown on the plug i replace and i know its running right.

doesnt this only really matter on a new plug when trying to dial in the carb?

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Update :(

Went out to start the bike last night and It wouldn't start. Tried reserve fuel, choke on and off and bump starting. When bump starting it made a judder sort of movement and refused to start. Its firing just not starting! The kick start feels dodgy and it usually starts first time. My fear is its seized!

Any help would be greatly appreciated!!

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Go ask your neighbour if you can borrow a wrench to take the pulg out. I fail to understand how you think you can guess your way into fixing this without tools. You should have taken the given advice and pulled the plug out days ago,now you have no choice you need to determin if you have spark,compression and you can 't do either without taking out the plug.

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I doubt a (box-end or open) wrench will work. You probably need a deep-well socket. But that may have been what you tried?

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ive got a dtr and a proper spark plug tool, its got the 45degree nuckle joint in it and i can slip it over the top of the plug then move it around so i can give a little pull and out she comes, just take the bite off it then in with the hands you go.

the trick is not to over tighten it for the next time, you want it nipped up so you cant turn it with your hands but you dont want it nipped up so tight that when you come to take it out it doesnt want to come out

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You need to up-jet,,,,,is it a 210 jet or a 240in it now? regardles you need to up-jet

you also need more air comming in, try cutting the snorkel making it shorter by half

then you need the right air mixture screw setting

then you need the right idle screw setting.

then you need to do a plug chop several times to make sure everything is ok.

on top of all this,,,,,,,, i dont like the big-one exhaust for the DT. they just dont seem to suit the bike. DEP is more suited to the bike.

The higher the revs you put on the bike the more the bikes leans out,,,,,,this is why you need plug chop after killing the engine during high revs,,,,,freewheel to a stop.

Because you have changed the exhaust, this means you change every setting for the carb and the air intake.

Forget about all settings you allready had,,,,,,,start fresh and do it right,,,,,,then you wont damage your piston,,,,,provided you havent allready.

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