Piaggio, low topspeed

this is unusual . you should be pulling hard even with the 70 kit .

do you have the stock CDI still ? what i would do is pull the race cdi ( they call it race but it aint its just a unlimited cdi) and pop in the stock cdi run the bike see how it feels. next i would look at the timing see whats happening with a timing gun when you blap the throttle, is it retarding itself for some sort of reason.

i know its not best practice , remove airbox fully and be ready to rejet, see if the open air feed allows you to run up higher , theres a restriction somewhere thats not allowing the full HP to be released

 

Thanks for the reply!

I have the original CDI and one unrestricted. Both are acting the same.

Before I downjetted from 100, i could rev the bike quite good (standing still) BUT the last rews was quite Hard to get up to. Had to stay at WOT for a while. Didnt try this after I put in 92 main.

Could always try to take off airbox and upjet again. Dont know If it will do anything though because I have drilled extra holes in airbox, just to let the carb get full airflow...

Will try that tomorrow and post a update.

 

Something has to be not right. Big time.
Wonder If it could be airleaks from my engineassemble. Will buy startinggas aswell and check for leaks.
Will Also check the durations with exact measure (already checked with cylinder off, but will check with cylinder on and a gradescale) Dont think this is the issue though.

 

you may need to preform a leak down test , use washing liquid in water and a spray bottle so when the motor case is under pressure you can spray the seam joins and see any leaking. that way you get a defined show if there is a case leak or not

 

Ok, tried different things today.
Checked Compression: 115 PSI (cold)
Sprayed starting gas all over the engine (drowned the engine) with no differens in idle. Not a single RPM up or down.
Checked durations. Exhaust 190 degrees, transfer and boost 120 degrees.
Cannot perform leak down test because I dont have the tools.

The calculations with CORRECT exhaustsystem, is that I should have 12 HP with 9000 RPM.

I really, really REALLY need a new exhaust!! Want to weld one myself so I can make it after my engine, but dont have a weld

I cant see that anything else could be the problem, or can someone else see something strange? A magic wizard?