eggsandbacon Posted July 15, 2011 Posted July 15, 2011 Hi there, I'm wondering if anyone can help me try to diagnose the issues I'm having with my DT. First let me start by saying I have very little knowledge with engines in general so I may end up just taking this to someone who knows what they are doing. I bought it last year but have only started riding it recently. It came with a full dep fitted, the rev limiter earthed and the snorkel removed from the airbox. These are the only visible changes and I'm unsure of if he/she has messed with the reeds, ypvs or carb. Anyway my problem is the bike isn't running smoothly at all. 1st minor issue: Cold start(not that it's exactly cold at this time of year): It starts no problems with the choke, if I try to turn the choke off instantly it bogs and stalls but if I leave it for a min then it's fine however it sometimes "sticks" revving quite high which is "reset" if I gently blip the throttle. 2nd more severe issue: The bike does not like being riden gently at all, it won't maintain a constant rev - spluttering like mad, but once it's opened up it's smooth as butter until I back off and the splutters return. 3rd annoying issue: When coming back onto the throttle at low revs there is a quite noticable jump.
Ryan09 Posted July 15, 2011 Posted July 15, 2011 Sounds like your power valve is pinned open which is why its horrible to ride at low rpm, be worth checking. (covers both issues 2 and 3) Starting from cold may just need to get used to as i recall mine used to be a bit of a pain at times and is a bit of a nak to it so dont worry too much, i found it idled okay when i took the choke of once it started to noticeably gain revs, sometimes caused a bit of excess smoke though which is not to worry.
eggsandbacon Posted July 15, 2011 Author Posted July 15, 2011 Ok cheers, I'll whip the cover off a bit later and see what it's doing. Before I do though, would I still hear the servo when engaging ignition if it was pinned open?
Ryan09 Posted July 15, 2011 Posted July 15, 2011 Depends if its been disconnected. Or they may have loosened the cables right off so when it does turn it wont do anything, so yes you may still hear it.
Moderator Airhead Posted July 15, 2011 Moderator Posted July 15, 2011 Ok cheers, I'll whip the cover off a bit later and see what it's doing. Before I do though, would I still hear the servo when engaging ignition if it was pinned open? Anyone in their right mind would have unplugged the PV motor if they pinned it full open though!
eggsandbacon Posted July 15, 2011 Author Posted July 15, 2011 Ok it wasn't pinned and was nice and clean, though in the returned position the cables seem slack (not sure if this is normal).
Moderator Airhead Posted July 15, 2011 Moderator Posted July 15, 2011 Ok it wasn't pinned and was nice and clean, though in the returned position the cables seem slack (not sure if this is normal). first thing is...after it's been running and then switched off the next swich on you should hear the characteristic zzzt...zzzt...zzzt of the PV cleaning cycle. After the last zzzt you should see the 'U' shaped cutout in the pulley aligns exactly with the 4mm blind hole behind in the cyl head. Now at this point adjust cables to achieve this, do NOT leave cable tight...just a little slack is required. At this point if the exhaust is removed, you can feel with your finger that the top of the exhaust port is smooth to the touch with no discerible bumps or grooves, if these are felt then the PV is mounted wrong in ralation to the pulley.
Ryan09 Posted July 15, 2011 Posted July 15, 2011 Anyone in their right mind would have unplugged the PV motor if they pinned it full open though! True but iv seen some random stuff on bikes recently so wouldnt be surprised and have heard of people doing this!
Moderator Airhead Posted July 15, 2011 Moderator Posted July 15, 2011 True but iv seen some random stuff on bikes recently so wouldnt be surprised and have heard of people doing this! yeah theres all sorts out there a Dt's seem to attract a fair number of em
Ryan09 Posted July 15, 2011 Posted July 15, 2011 Too true, then they break it, leave it in a mess for roughly 18months and then sell it on to someone else to deal with.
eggsandbacon Posted July 19, 2011 Author Posted July 19, 2011 It appears to line up fine but I didn't take the pipe off to check for lumps. Should this be my next move? I noticed today that it doesn't pull well in 6th too, eg: come to the brow of a medium hill high revs (guestimate ~9k), having pulled well up it through 4th and 5th then it struggles in 6th, the more throttle apllied the worse it appears. I also read that the mixer screw should be around 1.5 turns out, mine is like 3.
eggsandbacon Posted July 21, 2011 Author Posted July 21, 2011 Scrap the comment about 6th gear, I wasn't holding onto the revs/ shifting quick enough. There is a load of oil around where the exhaust meets the head, dribble from the silencer and all round where the frontpipe joins the silencer (bad join).
eggsandbacon Posted July 23, 2011 Author Posted July 23, 2011 I'm now quite worried/gutted; I took off the side panel to get at the exhaust and there was a river of oil collected in the heat shielded valley of the battery cover. Could this be down to it running rich for a while? or am I looking at gearbox oil in the fuel? I'm also very confused about the carb, my previous statement about the mixer screw is wrong. The mixer screw(flathead) should apparently be located just below the knurled idle screw(philips), in a hexagonal opening. On my carb this is blanked off. In the haynes manual it says to set it 1/4 turn out, not the 1 and 1/2 turns I keep seeing elsewhere.
Moderator Airhead Posted July 23, 2011 Moderator Posted July 23, 2011 I'm now quite worried/gutted; I took off the side panel to get at the exhaust and there was a river of oil collected in the heat shielded valley of the battery cover.Could this be down to it running rich for a while? or am I looking at gearbox oil in the fuel? I'm also very confused about the carb, my previous statement about the mixer screw is wrong. The mixer screw(flathead) should apparently be located just below the knurled idle screw(philips), in a hexagonal opening. On my carb this is blanked off. In the haynes manual it says to set it 1/4 turn out, not the 1 and 1/2 turns I keep seeing elsewhere. on the DTR there is a rubber connector joining the exhaust / silencer, is yours the same? and if so check it for splits / damage
eggsandbacon Posted July 23, 2011 Author Posted July 23, 2011 on the DTR there is a rubber connector joining the exhaust / silencer, is yours the same? and if so check it for splits / damage It's not the standard exhaust, rather a full dep system. There's no joining rubber, looks like the frontpipe is just a push fit (and a bad one at that) into the silencer.
Moderator Airhead Posted July 23, 2011 Moderator Posted July 23, 2011 It's not the standard exhaust, rather a full dep system. There's no joining rubber, looks like the frontpipe is just a push fit (and a bad one at that) into the silencer. Thats your problem then, it needs a seal...It will perform better with one as well. Take some measurements perhaps this is it ? http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=300558072498&ssPageName=ADME:B:WNASIF:GB:1123
eggsandbacon Posted July 23, 2011 Author Posted July 23, 2011 Thats your problem then, it needs a seal...It will perform better with one as well. Take some measurements perhaps this is it ? http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=300558072498&ssPageName=ADME:B:WNASIF:GB:1123 Ok thanks, I'll get a seal for it. What about the carb oddity?
eggsandbacon Posted July 25, 2011 Author Posted July 25, 2011 Right I have ordered the rubber gasket (that one was correct sizing, cheers) and also the metal crush gasket for the frontpipe. Forgive my ignorance but do you mean these leaky exhaust joints could be causing the spluttering, or just the cause of the mess? Anyway I whipped the little air bottle (not sure correct term) today and found what would appear to be the mixture screw hiding behind it.
eggsandbacon Posted July 25, 2011 Author Posted July 25, 2011 Right I have ordered the rubber gasket (that one was correct sizing, cheers) and also the metal crush gasket for the frontpipe. Forgive my ignorance but do you mean these leaky exhaust joints could be causing the spluttering, or just the cause of the mess? Anyway I whipped the little air bottle (not sure correct term) today and found what would appear to be the mixture screw hiding behind it. P.S What does that thing do anyway? I had the bike running briefly with it off and expected it to bog down with all the air, but it just sounded deeper. Edit: oops sorry mean't to edit other post not quote/reply.
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