Newb from Norway, Gilera Runner 50 sp 2004

Hi there. This bike is on the verge of driving me insane. It all started when i decided to put on a Airsal t6 kit (70cc). First i had serious issues with getting a black shoeshine textured oil buildup in the cylinder wich messed up things real good. and it would run just a few meters before it wouldnt be able to pull anymore.
This issue was solved by fitting new gaskets in the original carb (Delorto 17.5mm), wich was broken, and some places totally gone.

But it didn't stop there, not a all...
First off i will tell you whats been fitted on the bike, wich is as mentioned, a Airsal t6 70cc cylinder kit, Pollini hi speed variator kit, with the.... rollers and the 20kg contra spring installed ( it came with a 23kg spring allso), a derestricted Doppler premium exhaust, Doppler SX86 clutch with the white springs that it caame with installed, a new fuel pump and vakuum valve, and a new TP cdi and coil unit.

With all this installed the bike took off like a rocket and went well the first 200-300 meters, then it wouldn't accelerate and lost over 50% ov the power. But became noticeable better after i've made a completely stop ( engine still running ) and then i could take off again, but was far from rideable.

After a long time with troubleshooting an by reading tons of posts about the issue online, i'd come to the conclusion that a spacer or two was missing in the front pulley, and installed this, and voila, the bike accelerates a LOT better and i dont have to stop the bike completely to make it shift into low gear.
But, the issue with losing acceleration and power is till present, but occures after a much longer time, and not so severe as before, but enough to make it unrideable after a while.

It allso seems like the engine is getting way to hot, and water is allmost at boiling point after a few km, it sure feels like it. I cant say exact the temperature because the sensor is broken...
It allso wont pick up any speed from 3/4 throttle to Wot. It revs up well from about half throttle to full , but it wont pick up any speed, just rpm...this's a clutch issue maybe?

Or can it be the cylinder itself, or even the piston...?
Because before i installed the cylinder, i put on the piston rings and inserted the piston, and i had to use a bit of force to be able to move piston up and down in the cylinder, not much but enough to maybe start considering this to be a part of the problem...

Any thoughts on the issues would be much appreciated.

 

What weight are the rollers?

 

Hi, and sry about getting post in the wrong section, A bit tired .

Forgot to put in the weight of the rollers. Left space open there because i didn't remember the weight at the time and was supposed to fill it in...

Anyways, for the rollers, they are the 19x15.5 - 6.3 g, that came with the Pollini hi speed set.

It came with those and a set of 19x15.5 - 5 g.

 

Just went for about a km trip to the grocery store, to pick up some cowjuice. God, it runs well when cold/ running temperature, the bike allmost made a wheelie when going back up a small hill towards my house. Fun fun fun i say I just dont understand why it runs like sh..t after a longer period of riding. Maybe not getting enough cooling caused by a broken waterpump... ?
Either that or it's about to cease on me , and the cylinder are producing way to much heat, cuz of a previous overheated state or something.... can't recall that happening tho, but might be a possibility...?

In case of a broken waterpump.... this is located inside engine, and not possible to repair externally?
And is there any way to check if it's still operational..?