Scooterotica

Setting up a Monza 240 with touting tune.
Would there be a benefit in reducing the main Jet size and using the Powerjet on a Mikuni TMX30 for a touring tune which only revs to 7500rpm? It's blanked off at the moment. Would I risk leaning off the midrange too much? At what rpm or throttle opening does a Power Jet start to work?

i use a Mikuni TMX 30 on my TS-230 & JL3
im on the understanding that you can with it having a power jet you use a smaller main as the power jet comes into action at full throttle
this carb came with a 80 power jet & 195 main which i didnt risk

heres my jetting it may help 4 starters
pilot - 35
Float Valve - 3.5
Needle clip - 2.5 (thin washer under clip)
Main - 290
Power jet - 40 -- i did initially have a 30 fitted but upped it for safety

GL

Norrie Bodge wrote: ↑Sat Jan 22, 2022 8:38 pm i use a Mikuni TMX 30 on my TS-230 & JL3
im on the understanding that you can with it having a power jet you use a smaller main as the power jet comes into action at full throttle
this carb came with a 80 power jet & 195 main which i didnt risk

heres my jetting it may help 4 starters
pilot - 35
Float Valve - 3.5
Needle clip - 2.5 (thin washer under clip)
Main - 290
Power jet - 40 -- i did initially have a 30 fitted but upped it for safety

GL

Thanks for that.

The idea is supposed to me that main jet should be 75% and power jet 25%. So if you're using a 300 main with power blocked off, then you should be running something like 225 main with 75 power. On my 225 Mugello with LTH reed and TMX27 I erred on the cautious side and went 260 main with 50 power jet. I damaged the feed pipe to the power jet and blew it up as it obviously ran too lean when that happened. The pipe had been rubbing until a hole appeared in it. I blocked it off and just ran 310 main after that and it rode exactly the same and AFR was good on both set-ups on dyno. Unlike Dellorto it always ran clean at low revs even with higher main jet.