I need help guys!!!

[Josh]

You may or may not know that I installed my Malossi 68cc kit about a month ago. Along with that kit, I installed 13/43 sprockets, a new Barnett clutch and TP carbon fiber reeds. I heat cycled the bike about 4 times and then took it easy for about 35 miles. After that I started getting on it more aggresively. It was great for about 4 days, then I blew a motor mount. Got it fixed. While i started noticing the mount was going bad, I started noticing that the bike didn't have the power that it had when I first got everything going ok. After I got the mount fixed, I really noticed that it was slow!!! It is running no where near as fast as it should!!! I am running a 87 main jet on my Dellorto 21mm with the needle in the second clip. My top speed is 72mph which is way low for my setup. At first I thought it was the CF reeds that I had put in. I thought they were not working correctly. No, not that. I changed the reeds and still the same lack of power. Now I am thinking it is the piston rings not sealing and giving bad compression. Maybe I didn't break it in long enough? The thing that boggles my mind, is that there are no problems with the bike bogging or running bad, other than the very obvious lack of power!! I need help guys!!

I have not got around to tearing the bike down yet, but maybe this weekend if I can get some insight into what is going on here!!!

help guys!! and gals!!!

Josh

[sandbergdenmark]

i would say that the piston rings could be leaking.
rings don´t last so long on a high rpm motor

i´m currently using a stock hebo replica cilinder, which has a bit lower power than your malossi, and even so i can notice a big difference in power with only 1000km ( approx 600 miles ) on the ring.

[Josh]

I'm thinking the rings also. Also, has anyone noticed that on the Malossi rings, there is no marking to show what side is up?

i need more input!

Also, if I tear apart the motor this weekend, what would be some tell-tale signs of the rings going bad?

Josh

[sandbergdenmark]

most pistons i use there is no marking on the rings either, cuz it does´nt matter what way you turn them.

if they are very worn down you might see some shadows on them, but the best way is to put the ring in the cilinder, then take a new ring and put in next to it, and compare the gap between the ends, i normally change ring every 500 - 700 miles and i can see a noticeable difference in the gap.

[Josh]

I guess I will be tearing down the motor tomorrow and I'll try to decipher what is up.

Josh

[sandbergdenmark]

good luck:)

[BikerGeek]

Before you tear apart the motor, make sure the obvious stuff is OK. I would assume that you are using a higher-temp spark plug? Are you sure the plug is not fouled? I have 3,000 miles on my big bore kit including some track rides. My 75cc bike still makes great power.

If you find the problem, please post the results here.

Ride safe.

[micah apriliaforum com]

Check the compression.....it should be at least 100 psi.