DT125R ARCHIVE

tripr · Guru

Dtr just wont start dagged it with a car went lovley but it was a one off

louisBOSS · DTR Senior Member

3 things

fuel
compressin
spark

If a engine has , all 3 of them , theres no way it cannot start

bkray · DTR Senior Member

ok, mate, this may seem really simple and stupid, but im not taking the piss... take your fuel cap off and ride it like that (be careful not to spill any petrol) and then if it doesnt cut out after it usually does, problem solved. :D

tripr · Guru

thanks ill give it a shot m8 gonna give it another drag tomorrow just bought a compresion tester today too so ill be able to check it wen ebay delivers it

bkray · DTR Senior Member

yh, i mean, you should be able to feel the compression in your kick starter... but, a compression tester is a good idea. i mean, ive had a few problems with my bike and one of mine was that it wouldnt start. all because of the fuel cap. then i also had some problems with my air screw and choke but thats a different matter... i hope you get it sorted mate...

tripr · Guru

You suggesting it would work better with a breather hose drilled through the cap then m8 i remember my m8s old cr having one.
Im pretty new to kickstarts to be honest its the first bike iv had to use one on theve all been electric starter
I do think the carb was blocked up again sorted that out today ill find out tomorrow when my m8 gives me another tow . cos it stared pretty easy of the kick when i was warm the other day i think my idle an carbs probably ok. ran nice touched the powervalve to check it worked ok it sat an idled ok to.
noticed my spark plug sparks wheter my killswitch is on or off seem temperemental on both so iv ordered one of them too.
i hope it works i want a go even more now iv had a taste

DT-R_bradders · Guru

wats wrong with u man get that leg pumpin!!!

lol prob not the best idea gettin towed down the road tbh

it should start using the kickstart with the choke if it dont then u still got problems and i wouldnt bother bumpin it down the road to get it started

check the gause filters on the fuel tap and in the carb(pull off fuel pipe from tank and u will see it in the pipe on the carb , dig it out carefully with a pick or small flatblade screwdriver)

tripr · Guru

haha tell me about it i dream of just kick kick boom an your off. i do have a kickstart backup on my cheap chinesse deathtrap kicks over 1st pump. wish this dtr was the same
Ya right though m8 i did the filter 1st an there was half a cat crammed in there. been spotless since though checked it earlier just to be sure
thanks

bkray · DTR Senior Member

yh, pretty much suggesting a breather hole mate, im guessing your fuel isnt getting to the carb, i dont think the problem is in the carb itself tbh. :/ unless youve got it running wayyyyy too lean... mucked around with the air screw yet? stupid question but you checked your air filter?

tripr · Guru

Its got a flatside carb on it an iv only found one big screw in the side setting i one an a half turns out playing with a quarter turn each way to see if it worked yeah checked the filter cleaned it oiled it even tried easy start
my jet size is 240 on another forum i saw 240 is right when your powervalve is fully pegged open.
im not completly sure on the needle notches it was on the lowest notch 5th but iv put it 4th from the top now give that a go tomorrow

DT-R_bradders · Guru

that big screw in the side is the idle screw it litterally just lifts up the slide (basicaly holdin the throttle open a little bit) the screw bkray is on about is just below and to the right of the bigger one give tht a go m8

-- Edited by DT-R_bradders on Sunday 20th of February 2011 10:49:28 PM

DT-R_bradders · Guru

tripr wrote:

haha tell me about it i dream of just kick kick boom an your off. i do have a kickstart backup on my cheap chinesse deathtrap kicks over 1st pump. wish this dtr was the same
Ya right though m8 i did the filter 1st an there was half a cat crammed in there. been spotless since though checked it earlier just to be sure
did u check both sets of filters yea???

tripr · Guru

Both sets where do i have more then please m8

DT-R_bradders · Guru

which one did u do??? take the fuel tap off the tank and ther be two in there, and the one under the fuel pipe on the carb

tripr · Guru

yeah i did the fuel tubes base one the sock in the carb that had a load in it. ill pull the tap tomorrow an look at them. i did just turn the tap on over the garden to see the tap was ok an it poured outta both res an main quick on the floor

tripr · Guru

with the bike now doesnt seem to have an air ajustment at all . it should be beneath the carbs powerjet tube is that right cos mine has a threaded hole with a mullerd brass nug in the hole no air screw.

CooS · DTR Senior Member

It going to sound daft but have you checked you "KILL SWITCH" the red switch on your handle bar's!

I was riding home one day in snow and had these massive gloves on and caught that switch and it just died on side of road....i was there for like 30minutes tryed battery....bump starting it....took plug out try everything that i could! Then i thought hang on and tryed kill switch and she fired straight up biggrin

tripr · Guru

tried it m8 i was reacting ok but i checked it again an it sparks whatever posision its in am waitin on the ebay people sendin a new one to me . its the air mix screw that got me now cant seem to even find one

carl13671 · DTR Senior Member

The mixture screw should have tiny oring seals on it.
Try turning it right in and slowly turn out 1/8 turns at a time.Are you sure it should have a 240 jet in it??
Also put your needle valve at the middle setting,you could be flooding it which could explain the starting only with a pull.

tripr · Guru

To be honest with ya m8 Im not totally sure on anything with it yet its all new. Iv been all over the carb iv had a go on every needle setting now tried without the petrol cap on. tap filters are clear. bu i cant find this air mix screw anywhere it has one big screw in the left not another to be seen theres a diagonal hole down and right by the big air inlet. this must be it with something broke off deep inside

CooS · DTR Senior Member

It might be worth taking the head off and checking the piston ring's mate....i know you said there is load of compression but my scooter was the same but that had a heat seizer (barrel and piston where screwed)....

-- Edited by CooS on Monday 21st of February 2011 08:52:29 PM

DT-R_bradders · Guru

Thats the one m8 on the same side as the big one and u will need a slim flat blade to get in there, get some desent pics of it if u can so we can point ya in the right direction

Dingle001 · DTR Senior Member

I dont think yr problems lie with the carb. Just put the needle back on the middle clip and dont worry about the air screw. Even if its not set up perfectly it should still start with a good push.

If the only way you can start it is to tow it behind a car then it is very probably poor compression. The thumb test you did is not reliable - about 20psi would feel good but its going to take about 80 psi to ignite the fuel. The backfiring sounds like a problem I had a few weeks ago on an RM 125 where the power valve broke and was hitting the piston and jamming the ring in the groove which stopped the ring doing its job. Youd push it down the road and all youd get was an occasional pop from the exhaust and a bit of smoke. Soon as we fixed the PV and freed up the ring it was fine. Do the compression test with your new tester and take a reading. Then do another test and before you do it poor some oil down the plug hole - half an egg cup will be plenty, turn it over a couple of times and then take another reading. If the second test is much higher then rings/bore are your problem. Good luck and hope this helps.

tripr · Guru

Thanks for the reply m8 i did check out some others images online you can see where the airmix screw is pretty clearly on the rounside carb but the flatsides got one down this diagonal hole.if thats the one its got no head at all left to get it out .gutted spent almost 300 notes more on bits i probably dont even need an my bike still wont go , iv been tryin to get that knackered airmix screw out mosta the day too got a man sellin a carb on me good old ebay more cash lol

tripr · Guru

thanks for that m8 the backfiring has gone that was its original problem i fixed that myself hiden under the pickup coils wire cover was a break in both cable plastics at the same height where the copper wires were contacting thowing the timing out i think. when i got it i was told it had an new piston not to rag it cos it needed runnin in.

tripr · Guru

Got this airmix screw to move today an the bike sounded like it wanted to do start. but still no luck. try agian tomorrow
thanks for all the tips

ben_1_ · DTR Respected Member

Warm up the plug on the cooker and poor some petrol down spark plug hole and put the plug in while it is still hot/warm and see if it starts.

-- Edited by ben_1_ on Tuesday 22nd of February 2011 10:29:50 PM

tripr · Guru

Thanks tried it though m8 iv been cookin my 2 spark plugs interchanging from the start.
keep dropping a bit of petrol there to every now an then. it just aint startin still nearly drove me to breaking point today. its goin for an mot on the 7th an whatever work i cant do myself the shops gonna finish. just feels wrong now im a bit untrusting the mechanic i gave it to had it a month an didnt notice there wasnt an air mix screw , snapped my rear caliper bracket nicked my cdi hanger. an charged me a ton, all i want is my bike on the road

ben_1_ · DTR Respected Member

Where do you live m8 might be able to pop round and help you out!

tripr · Guru

Im in stoke on trent myself m8 near alton towers