Scooterotica

had scoot dynoe'd last week, as I nipped up. Was advised to upjet from a 90 (25mm delly btw) to a 95, seizure problem solved. But now in mid throttle it sounds like morse code & I have to rag it through the gears to eliminate it, I cant seem to ride gently without a spluttering engine note.

Any ideas please?

Wasn't it jetted correctly as part of the dyno session?

"Any ideas please?"... use a different dyno next time?

I never explained myself properly..I was running a 90 jet, I nipped up, took it to be dynoed & he said you need a 95, I bought a 95 when I got home & it does this intermitent running in mid throttle. No prob with the dyno whatsoever. Had scoots set up there before & all spot on.

Sounds like 95 was too big of a jump. They call it a main jet because it affects everything.

This is one of the reasons I don't think dyno's are the end all to tuning. They are a great resource to get that max HP out of a motor but that is under ideal conditions (unless the tuner understands road vs power tuning).

Did you open up the top end after the sieze? You might be wasting time trying jet a motor with a partially stuck ring.

ive also had a recent dyno session and found my scooter lumpy on the road
i partially agree it should run fine after being on the dyno,but i indicated i wanted my bike to run "safe"..(mainly for running in purposes)
so obviously he has set mine with plenty of fuel supplying the top end,so now im going through the process of lowering the needle and keeping an eye on things
sounds to me you just had run horsepower printout?surely he would have supplied the main jet himself if he was setting up your carb?

Sorted. It was the needle and to be fair he did tell me he was low on stock last week.