Hey, Ok, so ever since day one, I was only able to use just under full throttle, or she would bog completely out and have no power. This however didn't bother me as it's probably the difference of about 0.5 MPH and it's only for pottering about town, and easy to get used to etc. (I did have a thread on it but couldn't find it) So anyway, I cleaned the carb, which maybe made a slight difference, but it's done the same since. Recently, (about 18 months down the line) I had the same problem, but couldn't go passed 1/4 throttle, which again didn't bother me as it still sat at nearly 40 (clock speed). Next, it completely dies on pretty much ANY throttle, and is now un-rideable. Again, carbs cleaned and air filter etc. No change! I did have it running sweet again, with a fresh plug, but then I think I nicked the throttle cable and it started revving quite high, and I leant it over and let it 'do it's thing' until it calmed down, which it did. But then the same problem, couldn't apply any throttle at all! It ticks over fine, but will eventually die, like it's being starved? Went in for a sarnie, came back out, she fired up, ran, and then couldn't use the throttle again for a while. The throttle is very smooth with no play, and slider is working ok. Please help! I use her daily so want to get it sorted asap. I've had the problem before where the piston rings had gone and it ran fine until hot, but it's done under 12,000 KM so surely can't be that!? In regards to setup, everything is standard. It's a 2005 plate on a 17.5 Dellorto. The jets are 53 main and 32 pilot. Brass plate is out. Exhaust gas box is still connected. (sorry for the essay) Thanks.
Update.. Can get it started by blocking the air intake on the air box, and then letting a bit in to get it ticking over, but with full air flow it just revs uncontrollably. So I presume too much air / air leak somewhere? Mixture screw has always been 1 turn out (although Haynes says 1.5, my plug has been brown ish!) so left it that way.
I thought the same! I changed it for a spare I had kicking around, but it was still the same. I dug deeper, and opened the splitter box, and the cable was snagged so the slider wasn't sitting as low as it should have been. I think in my moment of panic when it revved up, I must have pulled it..! I hate doing it as never given up on a carb but I changed it and it's running ok now. I've got the mixture at 1.5 turns out, and the circlip was in the middle slot, which I left it at, but Haynes says top clip. Is that correct? If so I will change it as it's not running 100% always. Not checked the plug yet though, but had a long ride last night on it.
Try refitting brass plate, I had same probs with an nrg the plate doesnt restrict the performance of the bike it actually improved the performance when I fitted it (bike was standard derestricted) think without the plate the bike runs too lean. Hope that helps.
I have changed the needle height to the top notch, and she's now running better, but had a few moments where it's almost died for a few seconds like it's ran out of fuel, then suddenly kicks in again. I have recently had the exhaust welded due to it snapping off where it links to the EGR valve. Now the tube is just hanging, does it need to be blocked off at all, or will it not effect performance at all?
Yea I removed the plate thinking it would give more airflow but full throttle the bike kept bogging out from standstill so I did what you did put the clip on the needle on the bottom the only way I could make it run was to wind the mixture screw right in and quarter turn out which isnt right. Then went to local and very experienced scooter shop told me.to put.plate back in and set carb back to standard settings. I was dubious but low and behold the bike then flew off the mark and did 50-55 mph. If the restrictor (not egr) pipe has been chopped off the exhaust then I would put a bigger jet in the carb to 60 ish. Hope you get to the bottom of it I had the same crap with my nephews bike!!
measure your compression, sounds like its bad mixture... worth jetting up a little bit try a 56 main jet
