Im new to this forum so a big hi to everyone before I start.
Ive bought a 03 plate DTR with an Athena 170cc barrel on. It also has a full dep sport exhaust and the plug in the clocks has been disconected. The snorkal has been removed and its running a 240 main jet. The bike runs well and has plenty of power but it seems to bog down in the higher revs. It will only do 58ish flat out. Im nearly 14st so its pulling a big fat slob but i expected a bit more out of her. I used to have one of these years ago when I was 17 and if i remember rightly it was a little flying machine.
My bike had baffled me for months why it was so slow. I sorted out everything else similar to you including fitting a pv servo which is the first thing you should check out! I then found out today when i took the barrel off that new piston rings where fitted as i was told but the barrel never had a much needed rebore. So thats something to consider but hopefully your issue is more simple than that!
Hi, Nice to hear from you. Ive checked the PV and its all working and the lad i bought the bike off said it was a brand new barrel and piston. So im stuck again. lol
Hello mate, welcome, i haven't been into biking long myself so don't know to much, but what i can suggest is looking at your sprocket setup to see if it has been set up soley for acceleration, also never rely on what previous sellers say regarding what they've done to the bike, some will say anything just to sell, especially people selling dts with monster stickers all over them ;) therefore you could check compression, condition of top end etc. let us know how you get on
I've checked the compression and everything looks fine. I checked the jet size and it's got a240 in it so I'm going to try a 250 then 260. I was thinking of restricting the air flow after trying the jet but I just get the feeling it isn't getting enough fuel. Thanks for the advise guys. Much appreciated.
Not sure of the top end but it got to 70 without to much trouble. I think it will go off the clock if I pushed it. The good bit now is it want to lift the wheel in the first 3 gears just off the throttle. ; )
Hi mate welcome to th nut house ,once u hav cleared its throat ,take it for a full throttle run ,as u get to full throttle,grab a handful of clutch and kill th engine strait away ,when you coast to a stop,take the plug out and take a pic in good light ,it should be a nice digestive biscuit sort of colour right in the middle !chuck a pick up and we'll sort it show us th pic of your plug chop colour and it'llbe running like new
careful buying jets andy, theres two types, some times a 180= 1.8mm and sometimes not, a 240 main is almost 1.35mm, not 2.4mm
like the parts list for a dt200wr main jet says 160 or something like that and dt125r is 240, can be confusing
Cheers mate. Havnt yet looked at the jetting of the DTR but from a little run in the drive it appeared to be a nice light brown colour. Will need to do a plug chop soon though.
!chuck a pick up and we'll sort it 
show us th pic of your plug chop colour and it'llbe running like new 
