Bigsy Posted May 28, 2011 Share Posted May 28, 2011 Hi there, my 1999 DTR 125 has just developed a problem and I'm hoping you can help, When riding it'll get to 6k revs where the power valve kicks in and it just slowly struggles all the way up till about 8 and half k and won't rev anymore, but this isn't all the time, I can ride to work and the bike will be fine, the power kicks in and revving out to past 10k before changing gear, but then on the way home no power! My mate thought it was the plug breaking down so I fitted a new one and it's still the same. Iv not had it long and it's been fine up untill now, the guy I bought it of said the carb had not long been cleaned, I aways use good fuel and good two stroke oil. Also now on start up it's really smokey untill it's warmed up then there's no smoke what so ever, it's only got 9k on the clock but it does sound a bit rough and knocky. Iv recently put a new throttle cable on which was a cheap eBay job and oil pump part of the cable was way to long and wouldn't adjust enough so Iv had make some spacers up where the cable goes in to the pump housing, I'm now worried there's not been enough oil going in and Iv warn the rings and that's why it's smoky till it warms up! Some times it'll start first kick other times 15/20 kicks! Anyone with any ideas? Many thanks, Simon. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted May 28, 2011 Moderator Share Posted May 28, 2011 Simon smokey when cold is normal. Your bike likes to take you to work but not bring you home...was it a gift from the boss Link to comment Share on other sites More sharing options...
Bigsy Posted May 28, 2011 Author Share Posted May 28, 2011 Haha no not a gift from my boss, I was thinking maybe fuel starvation of some sort, maybe a blockage? I think I'll have a go at cleaning the carb, any tips on carb cleaning? I'm guessing just carefully strip it down and clean the jets then out back together using gasket sealant? Would it be worth me upping the main jet while Iv got it apart? The bike is derestricted with a full dep system. Cheers, Simon. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted May 28, 2011 Moderator Share Posted May 28, 2011 Haha no not a gift from my boss, I was thinking maybe fuel starvation of some sort, maybe a blockage? I think I'll have a go at cleaning the carb, any tips on carb cleaning? I'm guessing just carefully strip it down and clean the jets then out back together using gasket sealant? Would it be worth me upping the main jet while Iv got it apart? The bike is derestricted with a full dep system. Cheers, Simon. I'm not so sure it's the carb at fault here, the fact that it is ok sometimes and not others, if the carb were gunked up it would always be bad. by the way dont use gasket sealant on carbs, it's risky and completely unnnecessary. I have heard though that theres a filter gauze somewhere, possibly in the spigot that the fuel pipe attaches to...ask '2wheels' he mentioned it recently. is your PV operating ok? does it undego the cleaning cycle properly when you switch the key to ON? Link to comment Share on other sites More sharing options...
Bigsy Posted May 28, 2011 Author Share Posted May 28, 2011 Yes the PV seems to be working fine, you can hear it when you switch on, the fuel pipe recenty split near the tap so I chopped it off and refitted it the pipe, it's a bit short and stretched so I'll get some more pipe. The only other thing that Iv done to it is put Vaseline around the rubber on the fuel cap as was really tight, I did put alot on and it all washed of with the fuel, that was the day it started playing up, Iv been through a full tank since that and it's been playing up probably 40% of the time, could it be a bit of Vaseline causing a blockage? Simon. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted May 28, 2011 Moderator Share Posted May 28, 2011 Yes the PV seems to be working fine, you can hear it when you switch on, the fuel pipe recenty split near the tap so I chopped it off and refitted it the pipe, it's a bit short and stretched so I'll get some more pipe. The only other thing that Iv done to it is put Vaseline around the rubber on the fuel cap as was really tight, I did put alot on and it all washed of with the fuel, that was the day it started playing up, Iv been through a full tank since that and it's been playing up probably 40% of the time, could it be a bit of Vaseline causing a blockage? Simon. maybe /maybe not You may have blocked the venting hole on the filler cap with vaseline? When it starts acting up pull over, undo the filler cap and re fasten it then ride again...see if its better...If it is you need to discover how it vents and clear the blockage. Link to comment Share on other sites More sharing options...
Bigsy Posted May 30, 2011 Author Share Posted May 30, 2011 Well Iv checked the venting and that's fine, Iv checked the fuel is coming out of the fuel tap ok and the fuel pipe is clear and flowing, that's all good. I rode to work just now and it was not revving well then about half way to work it suddenly cleared and was lovely...for about five minute! It then wouldn't rev past 6k and struggled to get there! It wouldn't go up hills without me dropping in to second! And I could be in my head but I'm sure I could smell a different smell when I stopped and it didn't sound right! I really not sure what to try now, any ideas? Cheers, Simon. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted May 30, 2011 Moderator Share Posted May 30, 2011 not sure about the smell, thats a bit worrying! water in the carb bowl can do this symptom though, try draining the bowl. Link to comment Share on other sites More sharing options...
Bigsy Posted May 30, 2011 Author Share Posted May 30, 2011 The smell could of been in my head lol, it has been raining the last couple of days and the bike is stood out side, I'm thinking of taking the carb off and giving it a good clean, any tip on the best way to clean and also sealing it when putting it back together? Should I buy a gasket kit and where would the best place to get one? Or should I just take it to my local bike shop and ask them to recon it? Cheers, Simon. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted May 30, 2011 Moderator Share Posted May 30, 2011 I would drain the bowl before going to all that bother, sometimes you will see a drain screw at the bottom, if so catch any fuel that comes out rather than letting it go everywhere. Link to comment Share on other sites More sharing options...
Bigsy Posted May 30, 2011 Author Share Posted May 30, 2011 Ok I'll try that tomorrow, I'll keep you posted, and thank you for all the advice, Simon. Link to comment Share on other sites More sharing options...
2 Wheels Posted May 30, 2011 Share Posted May 30, 2011 Aye try draining the float bowl,,,,,by the drain screw,,,,,,if ya dont have a drain screw then just take the bottom off = float bowl,,,,,,,,,,you wont need a new gasket unless the one that comes off is broken and cracked. If ya dont want to toutch the carb,,,,,,,,,,,,,,my local bike shop only charges a fiver for a carb clean,,,,,,,,so mabey cheep there at you also. One thing to check,,,,,,,,if its on your carb,,probably is,,,,,,,,,,,,From the float bowl chamber to the main body of the carb there will be a little pipe conecting the two. This is the power jet pipe.It is important to be clean and free-flowing. There is also a jet inside the carb where this pipe is conected,,,,,it is not removeable but does need to be blown out. Sounds like fuel starvation problem to me. Link to comment Share on other sites More sharing options...
Bigsy Posted May 30, 2011 Author Share Posted May 30, 2011 Thanks for the reply 2 wheels, I will try all this tomorrow and keep you posted. Cheers, Simon. Link to comment Share on other sites More sharing options...
Bigsy Posted May 30, 2011 Author Share Posted May 30, 2011 Well came home from work at a slow speed lol, I took the carb off but the draining screw and screws holding the bottom of the carb on were all chewed up so gave it a good shake to get the fuel out and blew all the pipes with my compressor, i then checked the power valve was set in the right place and working, put it all back together and it's much better, it does have a flat spot between 6k and 7k which is really anoying and it doesnt feel as fast as it was, but that could be me getting use to it. Iv just ordered a bigger main jet (#230) but not sure how I'm gonna fit it if all the carb screws are chewed up, even the air/fuel mixure screw is ceased! Any ideas? Cheers, Simon. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted May 30, 2011 Moderator Share Posted May 30, 2011 .... Iv just ordered a bigger main jet (#230) but not sure how I'm gonna fit it if all the carb screws are chewed up, even the air/fuel mixure screw is ceased! Any ideas? Cheers, Simon. order some new screws from yambits or get a good set of mole grips and gently grip the heads of the screws to loosen then, dont overdo the grip or you'll make matters worse. They wont be all that tight. Dunno about the mixture screw. Always use well fitting screwdrivers though or you will damage screws when they slip. Link to comment Share on other sites More sharing options...
Bigsy Posted May 31, 2011 Author Share Posted May 31, 2011 Iv ordered some new float bowl screws so fitting the new jet shouldn't be a problem but the mixture screw is so chewed up and even the tunnel and threads of where it fits are compleatly ruined, so is that gonna be a problem if I fit the bigger main jet? Cheers, Simon. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted May 31, 2011 Moderator Share Posted May 31, 2011 no, changing the main jet wont have much affect on the pilot mixture setting. Link to comment Share on other sites More sharing options...
Bigsy Posted June 1, 2011 Author Share Posted June 1, 2011 That's good then. Well decided to drain the fuel tank and put some fresh premixed fuel in as I'm not to sure on throttle cable set up that I put on, found a datatag thingy floating around in the tank lol, so put her all back together and took her for a ride and guess what! Riding like a bag of sh#t again! Wouldnt rev past 7k! So I pulled over switched her off and on again and she was fine apart from the small flat spot between 6 and 7k, and again this morning fine, so would this indicate something wrong with the PV? it always makes a noise when turning the ignition on, the cleaning cycle I think they call it? And it seems to do this at ease, any ideas? Cheers, Simon. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted June 1, 2011 Moderator Share Posted June 1, 2011 Simon is the PV set up correctly aligned? Also the cables must not be tight Link to comment Share on other sites More sharing options...
Bigsy Posted June 1, 2011 Author Share Posted June 1, 2011 I took the pipe off and checked the PV and it seems to be aligned, not sure how tight the cables are but I know there is no slack in them, when the cover is off you can see that the PV moves freeley with the switching of the ignition, I'll try slackening the cabels off a bit and see if that helps. I'll keep you posted and thanks for all the help and advice so far. Cheers, Simon. Link to comment Share on other sites More sharing options...
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