Sheddybiker

Thanks for that Pat, It's all starting to make a bit more sense. Do you know if there is a way to check which CDI is fitted, any tell tale numbers or markings? At least at the moment the bike is running and useable. The previous owner had done the green/black wire to earth.thing, which I had disconnected whilst attempting to get back to base settings as it were. Would this be worthwhile reinstating do you think?

I have been wondering myself about the age thing. log book states 89 but i think it's a later engine. The kick start is blanked off as is the Rev counter drive, rubber seal where I think it should be. I had thought that it may have an electrical tacho but on checking the clocks you can see where the drive cable should be. Markings on the head read 3MB, and 3MBOO 125cm3 on the base of the barrel

Thanks 2 wheels,I have adjusted both cables as evenly as I can, even played around with different tensions and lengths but there is still the fluctuation on a constant throttle. had the bike stripped down and checked that the servo was strutting its stuff. No I cant see another junction box anywhere along the line after the servo. Does the servo get its signal from the ECU ? I would have expected the valve to remain open on a constant throttle? And to be fair to the bike it almost always starts at the first push of the button

Well I think I've got the problem narrowed down to the power valve not functioning properly. The oil burning cleared up but the bike was still running rougher than a big rough thing on 'Rough Tuesday'. I decided to have another look at the power valve set up, and it doesn't look good. Setting up, using the drill bit to align the pulley was fine, turn ignition on and it completes it's cleaning sweep and returns to where it set off from. But rev the engine enough for the valve to operate and it comes to rest quite a few degrees off, but re aligns when i turn the ignition back on. Also, when running the engine with the pulley cover off, the valve fluctuates,opening and closing even on a constant throttle. I'm (obviously) no expert but surely this can't be right? The upshot is that I've unplugged the servo. The bike now runs without the farting and belching (unlike myself) and the spread of power is fairly smooth and even, if a little down, until higher revs when it still hits the power band. Any ideas what the problem might be?? Bad signal from the ECU?

Just had a good sniff but all I can smell is transmission oil. and no there doesn't appear to be any crank breather. There is a blanked off orifice on top of the cases just above the gear box fillercap but this looks like a factory blank?

Thanks guys. the trip is 10 miles each way but no real chance to get her lit up. I was having some suspicion about the crank seals. I have some memories of if you change the 2T it's been used to it can cause problems. I went for a semi synth as the safer bet not knowing what's been in previously. I'll give it a good sniffing at in the morning. One suggestion that was put to me was to disconnect the oil pump and run on pre mix for a couple of days. Any idea what ratio?? 40:1 ? Then if she runs OK therein lies the problem?

Hi, Newbie here, Have recently bought an 89 DTR125R, which wasn't running too well.. I firstly cleared out all of the old fuel,filled the tank with a good semi synth 2T, stripped and cleaned the flatslide carb. and cleaned and oiled the air filter. New BR9ES plug slotted into place, hit the button and off I went,, But not too quickly, it was stuttering and mis firing, then clearing a little but would not go past 40mph, My immediate suspicion was the power valve. Taking off the cover i was confronted with a short length of threaded bolt but no head and the pulley floating about doing not much. I removed the (DEP) exhaust and, following suggestions found on this site, reset the power valve to normal operating settings. All back together and....... Revelation, crisp, free revving, quick,(up to 65mph) and soooo much fun. I returned to the garage laughing like a loon in my helmet. It was like being 17 all over again. Now for the bad bit. Having used the bike for my daily commute to work (10 miles each way) for a few weeks, I was on my way to work, lightish traffic, bimbling along at 30 - 35 when the bike started stuttering again and bogging down and I couldn't get much more than 20mph. with a rooster tail of dark blue/grey smoke engulfing the countryside. Luckily, not too far from work. I let her cool off and at lunch time fired her up and revved her out a bit, after a couple of minutes she was running cleaner so i ran her up a fairly steep hill for about 1/2 mile, keeping the revs up, and returned running fine. Made it home with no problems. Following day and she is running badly again,Checked the plug, which was sooty but with a cocoa coloured electrode and again smoking like a frenchman. My thoughts are that it is burning too much 2 stroke, but again, using info found on here, the pump settings seem ok, and why so suddenly any way?? Suggestions please

Hello, New member who, like a lot of others no doubt,turns to you in times of strife to appeal to your better nature and superior knowledge. I have recently purchased an '89 DTR125R, but also run an 09 Kawasaki Z1000 and, occasionally (I can't fold up into position any more) a Ducati 900ssie. Hope to speak with some of your enlightened members on the 'Why won't it run properly pages' lol