Scooterotica

Hello folks.
I thought I had solved my running problems by binning the jettex carb but the scoot still cuts out on me.
It's an LI 125. 175 head. Scoot rs exhaust.running a 26 mm dellorto, no filter, no air scoop. Fast flow tap.
It starts perfectly, runs well up to around 35 mph where it begins to stutter. Only does 40mph max. Today it cut out going up a slight hill at around 35 ish. Pulled over, it kicked straight away, off I went.
Am still running the engine in after a rebuild and quite happy pottering around at 30 everywhere but can't risk any longer runs out!!!!

Where should I go next to get it running properly?

Thanks.

Electrics: start with the easy ones, spark plug, suppressor cap, ht lead, etc....eventually leading to stator/flywheel. Might be worth checking (multi-meter) stator readings early on.

has the head been matched to cylinder?

All electrics are new, 12 v conversion.
Also tried the carb needle on each different setting but no change.
The head has not been matched to the cylinder, do I need to get it done?

I was thinking it would be a carb/jetting issue?

Cheers.

i,m confused ..as a std 125 would do more than 40mph ..
and you say that you have a 175 head on it ?

Yes mate. It's an LI 125 with a 175 head and piston.

still fuel related Id say, the clue being that there was no change when moving the needle through all 4 settings

Definitely something very wrong there!

I wish everyone that hates jetex carbs 'cos there shite would send them to me

Oh, is the scootrs exhaust a mild steel or stainless?

It's a stainless scooters exhaust.
Tried fettling with the jettex for a long time. I tried various combinations of the jets upon advice from the place where I get my parts.
There was a immediate improvement when I put the dellorto on. But it still splutters at around 35 ish and won't go past 40.
I wondered if the reason why it cuts out when I was going uphill was down to starvation but it fired up straight away when I pulled over!!!!???

Cheers.

Does this happen when you get to a specific speed or specific distance? I only ask as I had a similar problem after I had gone about 500m. Would then start after a minute and happen again 500 metres down the road. Turned out the petrol inner hose had kinked just below the tap but wasn't obvious because it had an outer on it. was the last thing I looked at... .the hose closed up when I sat
On it and therefor only had a bowels worth of juice. After a minute of me standing there with the weight off it would refill and start.

Anyway now run a clear hose but had an issue with it being nipped up between the metal part of the bumpstop and the frame.

Good luck